From 9bc4fbbd3ce32ae2c4bd4f1b6f548589ec5059e2 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Mon, 29 Jan 2018 14:27:39 +0000
Subject: [PATCH 01/60] Drop 'transform', and remove 'inplace' transformations.

---
 coreapi/client.py          | 27 ++++++--------------
 coreapi/codecs/corejson.py |  5 +---
 coreapi/codecs/python.py   |  2 --
 coreapi/document.py        | 10 +-------
 coreapi/transports/http.py | 31 +----------------------
 tests/test_codecs.py       |  2 --
 tests/test_document.py     |  9 +------
 tests/test_transitions.py  | 52 +++++++++-----------------------------
 8 files changed, 24 insertions(+), 114 deletions(-)

diff --git a/coreapi/client.py b/coreapi/client.py
index d02a59c..7321ebd 100644
--- a/coreapi/client.py
+++ b/coreapi/client.py
@@ -1,19 +1,15 @@
 from coreapi import codecs, exceptions, transports
 from coreapi.compat import string_types
-from coreapi.document import Document, Link
+from coreapi.document import Link
 from coreapi.utils import determine_transport, get_installed_codecs
-import collections
 import itypes
 
 
-LinkAncestor = collections.namedtuple('LinkAncestor', ['document', 'keys'])
-
-
 def _lookup_link(document, keys):
     """
     Validates that keys looking up a link are correct.
 
-    Returns a two-tuple of (link, link_ancestors).
+    Returns the Link.
     """
     if not isinstance(keys, (list, tuple)):
         msg = "'keys' must be a list of strings or ints."
@@ -28,7 +24,6 @@ def _lookup_link(document, keys):
     # 'node' is the link we're calling the action for.
     # 'document_keys' is the list of keys to the link's parent document.
     node = document
-    link_ancestors = [LinkAncestor(document=document, keys=[])]
     for idx, key in enumerate(keys):
         try:
             node = node[key]
@@ -36,9 +31,6 @@ def _lookup_link(document, keys):
             index_string = ''.join('[%s]' % repr(key).strip('u') for key in keys)
             msg = 'Index %s did not reference a link. Key %s was not found.'
             raise exceptions.LinkLookupError(msg % (index_string, repr(key).strip('u')))
-        if isinstance(node, Document):
-            ancestor = LinkAncestor(document=node, keys=keys[:idx + 1])
-            link_ancestors.append(ancestor)
 
     # Ensure that we've correctly indexed into a link.
     if not isinstance(node, Link):
@@ -48,7 +40,7 @@ def _lookup_link(document, keys):
             msg % (index_string, type(node).__name__)
         )
 
-    return (node, link_ancestors)
+    return node
 
 
 def _validate_parameters(link, parameters):
@@ -140,8 +132,8 @@ def reload(self, document, format=None, force_codec=False):
         return self.get(document.url, format=format, force_codec=force_codec)
 
     def action(self, document, keys, params=None, validate=True, overrides=None,
-               action=None, encoding=None, transform=None):
-        if (action is not None) or (encoding is not None) or (transform is not None):
+               action=None, encoding=None):
+        if (action is not None) or (encoding is not None):
             # Fallback for v1.x overrides.
             # Will be removed at some point, most likely in a 2.1 release.
             if overrides is None:
@@ -150,8 +142,6 @@ def action(self, document, keys, params=None, validate=True, overrides=None,
                 overrides['action'] = action
             if encoding is not None:
                 overrides['encoding'] = encoding
-            if transform is not None:
-                overrides['transform'] = transform
 
         if isinstance(keys, string_types):
             keys = [keys]
@@ -160,7 +150,7 @@ def action(self, document, keys, params=None, validate=True, overrides=None,
             params = {}
 
         # Validate the keys and link parameters.
-        link, link_ancestors = _lookup_link(document, keys)
+        link = _lookup_link(document, keys)
         if validate:
             _validate_parameters(link, params)
 
@@ -169,10 +159,9 @@ def action(self, document, keys, params=None, validate=True, overrides=None,
             url = overrides.get('url', link.url)
             action = overrides.get('action', link.action)
             encoding = overrides.get('encoding', link.encoding)
-            transform = overrides.get('transform', link.transform)
             fields = overrides.get('fields', link.fields)
-            link = Link(url, action=action, encoding=encoding, transform=transform, fields=fields)
+            link = Link(url, action=action, encoding=encoding, fields=fields)
 
         # Perform the action, and return a new document.
         transport = determine_transport(self.transports, link.url)
-        return transport.transition(link, self.decoders, params=params, link_ancestors=link_ancestors)
+        return transport.transition(link, self.decoders, params=params)
diff --git a/coreapi/codecs/corejson.py b/coreapi/codecs/corejson.py
index f025533..92facc4 100644
--- a/coreapi/codecs/corejson.py
+++ b/coreapi/codecs/corejson.py
@@ -196,8 +196,6 @@ def _document_to_primitive(node, base_url=None):
             ret['action'] = node.action
         if node.encoding:
             ret['encoding'] = node.encoding
-        if node.transform:
-            ret['transform'] = node.transform
         if node.title:
             ret['title'] = node.title
         if node.description:
@@ -264,7 +262,6 @@ def _primitive_to_document(data, base_url=None):
         url = urlparse.urljoin(base_url, url)
         action = _get_string(data, 'action')
         encoding = _get_string(data, 'encoding')
-        transform = _get_string(data, 'transform')
         title = _get_string(data, 'title')
         description = _get_string(data, 'description')
         fields = _get_list(data, 'fields')
@@ -278,7 +275,7 @@ def _primitive_to_document(data, base_url=None):
             for item in fields if isinstance(item, dict)
         ]
         return Link(
-            url=url, action=action, encoding=encoding, transform=transform,
+            url=url, action=action, encoding=encoding,
             title=title, description=description, fields=fields
         )
 
diff --git a/coreapi/codecs/python.py b/coreapi/codecs/python.py
index 6265a28..6feec4e 100644
--- a/coreapi/codecs/python.py
+++ b/coreapi/codecs/python.py
@@ -42,8 +42,6 @@ def _to_repr(node):
             args += ", action=%s" % repr(node.action)
         if node.encoding:
             args += ", encoding=%s" % repr(node.encoding)
-        if node.transform:
-            args += ", transform=%s" % repr(node.transform)
         if node.description:
             args += ", description=%s" % repr(node.description)
         if node.fields:
diff --git a/coreapi/document.py b/coreapi/document.py
index c6c9ceb..dd498dc 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -187,15 +187,13 @@ class Link(itypes.Object):
     """
     Links represent the actions that a client may perform.
     """
-    def __init__(self, url=None, action=None, encoding=None, transform=None, title=None, description=None, fields=None):
+    def __init__(self, url=None, action=None, encoding=None, title=None, description=None, fields=None):
         if (url is not None) and (not isinstance(url, string_types)):
             raise TypeError("Argument 'url' must be a string.")
         if (action is not None) and (not isinstance(action, string_types)):
             raise TypeError("Argument 'action' must be a string.")
         if (encoding is not None) and (not isinstance(encoding, string_types)):
             raise TypeError("Argument 'encoding' must be a string.")
-        if (transform is not None) and (not isinstance(transform, string_types)):
-            raise TypeError("Argument 'transform' must be a string.")
         if (title is not None) and (not isinstance(title, string_types)):
             raise TypeError("Argument 'title' must be a string.")
         if (description is not None) and (not isinstance(description, string_types)):
@@ -211,7 +209,6 @@ def __init__(self, url=None, action=None, encoding=None, transform=None, title=N
         self._url = '' if (url is None) else url
         self._action = '' if (action is None) else action
         self._encoding = '' if (encoding is None) else encoding
-        self._transform = '' if (transform is None) else transform
         self._title = '' if (title is None) else title
         self._description = '' if (description is None) else description
         self._fields = () if (fields is None) else tuple([
@@ -231,10 +228,6 @@ def action(self):
     def encoding(self):
         return self._encoding
 
-    @property
-    def transform(self):
-        return self._transform
-
     @property
     def title(self):
         return self._title
@@ -253,7 +246,6 @@ def __eq__(self, other):
             self.url == other.url and
             self.action == other.action and
             self.encoding == other.encoding and
-            self.transform == other.transform and
             self.description == other.description and
             sorted(self.fields, key=lambda f: f.name) == sorted(other.fields, key=lambda f: f.name)
         )
diff --git a/coreapi/transports/http.py b/coreapi/transports/http.py
index a548024..cf63be9 100644
--- a/coreapi/transports/http.py
+++ b/coreapi/transports/http.py
@@ -305,32 +305,6 @@ def _decode_result(response, decoders, force_codec=False):
     return result
 
 
-def _handle_inplace_replacements(document, link, link_ancestors):
-    """
-    Given a new document, and the link/ancestors it was created,
-    determine if we should:
-
-    * Make an inline replacement and then return the modified document tree.
-    * Return the new document as-is.
-    """
-    if not link.transform:
-        if link.action.lower() in ('put', 'patch', 'delete'):
-            transform = 'inplace'
-        else:
-            transform = 'new'
-    else:
-        transform = link.transform
-
-    if transform == 'inplace':
-        root = link_ancestors[0].document
-        keys_to_link_parent = link_ancestors[-1].keys
-        if document is None:
-            return root.delete_in(keys_to_link_parent)
-        return root.set_in(keys_to_link_parent, document)
-
-    return document
-
-
 class HTTPTransport(BaseTransport):
     schemes = ['http', 'https']
 
@@ -366,7 +340,7 @@ def __init__(self, credentials=None, headers=None, auth=None, session=None, requ
     def headers(self):
         return self._headers
 
-    def transition(self, link, decoders, params=None, link_ancestors=None, force_codec=False):
+    def transition(self, link, decoders, params=None, force_codec=False):
         session = self._session
         method = _get_method(link.action)
         encoding = _get_encoding(link.encoding)
@@ -379,9 +353,6 @@ def transition(self, link, decoders, params=None, link_ancestors=None, force_cod
         response = session.send(request)
         result = _decode_result(response, decoders, force_codec)
 
-        if isinstance(result, Document) and link_ancestors:
-            result = _handle_inplace_replacements(result, link, link_ancestors)
-
         if isinstance(result, Error):
             raise exceptions.ErrorMessage(result)
 
diff --git a/tests/test_codecs.py b/tests/test_codecs.py
index 32458cd..2475293 100644
--- a/tests/test_codecs.py
+++ b/tests/test_codecs.py
@@ -194,7 +194,6 @@ def test_link_encodings(json_codec):
     doc = Document(content={
         'link': Link(
             action='post',
-            transform='inplace',
             fields=['optional', Field('required', required=True, location='path')]
         )
     })
@@ -204,7 +203,6 @@ def test_link_encodings(json_codec):
     "link": {
         "_type": "link",
         "action": "post",
-        "transform": "inplace",
         "fields": [
             {
                 "name": "optional"
diff --git a/tests/test_document.py b/tests/test_document.py
index 6b06de7..c985fa9 100644
--- a/tests/test_document.py
+++ b/tests/test_document.py
@@ -17,7 +17,6 @@ def doc():
             'link': Link(
                 url='/',
                 action='post',
-                transform='inplace',
                 fields=['optional', Field('required', required=True, location='path')]
             ),
             'nested': {'child': Link(url='/123')}
@@ -224,7 +223,7 @@ def test_document_repr(doc):
         "'integer': 123, "
         "'list': [1, 2, 3], "
         "'nested': {'child': Link(url='/123')}, "
-        "'link': Link(url='/', action='post', transform='inplace', "
+        "'link': Link(url='/', action='post', "
         "fields=['optional', Field('required', required=True, location='path')])"
         "})"
     )
@@ -345,7 +344,6 @@ def test_document_equality(doc):
         'link': Link(
             url='/',
             action='post',
-            transform='inplace',
             fields=['optional', Field('required', required=True, location='path')]
         ),
         'nested': {'child': Link(url='/123')}
@@ -424,11 +422,6 @@ def test_link_action_must_be_string():
         Link(action=123)
 
 
-def test_link_transform_must_be_string():
-    with pytest.raises(TypeError):
-        Link(transform=123)
-
-
 def test_link_fields_must_be_list():
     with pytest.raises(TypeError):
         Link(fields=123)
diff --git a/tests/test_transitions.py b/tests/test_transitions.py
index a31ba13..28e2ad0 100644
--- a/tests/test_transitions.py
+++ b/tests/test_transitions.py
@@ -1,24 +1,14 @@
 # coding: utf-8
 from coreapi import Document, Link, Client
 from coreapi.transports import HTTPTransport
-from coreapi.transports.http import _handle_inplace_replacements
 import pytest
 
 
 class MockTransport(HTTPTransport):
     schemes = ['mock']
 
-    def transition(self, link, decoders, params=None, link_ancestors=None):
-        if link.action == 'get':
-            document = Document(title='new', content={'new': 123})
-        elif link.action in ('put', 'post'):
-            if params is None:
-                params = {}
-            document = Document(title='new', content={'new': 123, 'foo': params.get('foo')})
-        else:
-            document = None
-
-        return _handle_inplace_replacements(document, link, link_ancestors)
+    def transition(self, link, decoders, params=None):
+        return {'action': link.action, 'params': params}
 
 
 client = Client(transports=[MockTransport()])
@@ -29,7 +19,6 @@ def doc():
     return Document(title='original', content={
         'nested': Document(content={
             'follow': Link(url='mock://example.com', action='get'),
-            'action': Link(url='mock://example.com', action='post', transform='inplace', fields=['foo']),
             'create': Link(url='mock://example.com', action='post', fields=['foo']),
             'update': Link(url='mock://example.com', action='put', fields=['foo']),
             'delete': Link(url='mock://example.com', action='delete')
@@ -40,44 +29,27 @@ def doc():
 # Test valid transitions.
 
 def test_get(doc):
-    new = client.action(doc, ['nested', 'follow'])
-    assert new == {'new': 123}
-    assert new.title == 'new'
-
-
-def test_inline_post(doc):
-    new = client.action(doc, ['nested', 'action'], params={'foo': 123})
-    assert new == {'nested': {'new': 123, 'foo': 123}}
-    assert new.title == 'original'
+    data = client.action(doc, ['nested', 'follow'])
+    assert data == {'action': 'get', 'params': {}}
 
 
 def test_post(doc):
-    new = client.action(doc, ['nested', 'create'], params={'foo': 456})
-    assert new == {'new': 123, 'foo': 456}
-    assert new.title == 'new'
+    data = client.action(doc, ['nested', 'create'], params={'foo': 456})
+    assert data == {'action': 'post', 'params': {'foo': 456}}
 
 
 def test_put(doc):
-    new = client.action(doc, ['nested', 'update'], params={'foo': 789})
-    assert new == {'nested': {'new': 123, 'foo': 789}}
-    assert new.title == 'original'
+    data = client.action(doc, ['nested', 'update'], params={'foo': 789})
+    assert data == {'action': 'put', 'params': {'foo': 789}}
 
 
 def test_delete(doc):
-    new = client.action(doc, ['nested', 'delete'])
-    assert new == {}
-    assert new.title == 'original'
+    data = client.action(doc, ['nested', 'delete'])
+    assert data == {'action': 'delete', 'params': {}}
 
 
 # Test overrides
 
 def test_override_action(doc):
-    new = client.action(doc, ['nested', 'follow'], overrides={'action': 'put'})
-    assert new == {'nested': {'new': 123, 'foo': None}}
-    assert new.title == 'original'
-
-
-def test_override_transform(doc):
-    new = client.action(doc, ['nested', 'update'], params={'foo': 456}, overrides={'transform': 'new'})
-    assert new == {'new': 123, 'foo': 456}
-    assert new.title == 'new'
+    data = client.action(doc, ['nested', 'follow'], overrides={'action': 'put'})
+    assert data == {'action': 'put', 'params': {}}

From b9f9dd76a4b9a7f67e9744b5e506d52be80044e0 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 30 Jan 2018 14:26:57 +0000
Subject: [PATCH 02/60] Drop action= and encoding= parameters on client, in
 favor of override

---
 coreapi/client.py | 13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

diff --git a/coreapi/client.py b/coreapi/client.py
index b005eae..ece3d27 100644
--- a/coreapi/client.py
+++ b/coreapi/client.py
@@ -131,18 +131,7 @@ def reload(self, document, format=None, force_codec=False):
         # Fallback for v1.x. To be removed in favour of explict `get` style.
         return self.get(document.url, format=format, force_codec=force_codec)
 
-    def action(self, document, keys, params=None, validate=True, overrides=None,
-               action=None, encoding=None):
-        if (action is not None) or (encoding is not None):
-            # Fallback for v1.x overrides.
-            # Will be removed at some point, most likely in a 2.1 release.
-            if overrides is None:
-                overrides = {}
-            if action is not None:
-                overrides['action'] = action
-            if encoding is not None:
-                overrides['encoding'] = encoding
-
+    def action(self, document, keys, params=None, validate=True, overrides=None):
         if isinstance(keys, string_types):
             keys = [keys]
 

From 4fb5e883c2dc2472b656f089d5298eb30e78c937 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 30 Jan 2018 14:29:33 +0000
Subject: [PATCH 03/60] Drop HTTPTransport 'credentials' in favor of 'auth'

---
 coreapi/transports/http.py | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/coreapi/transports/http.py b/coreapi/transports/http.py
index 5b78fc7..0b13b03 100644
--- a/coreapi/transports/http.py
+++ b/coreapi/transports/http.py
@@ -308,7 +308,7 @@ def _decode_result(response, decoders, force_codec=False):
 class HTTPTransport(BaseTransport):
     schemes = ['http', 'https']
 
-    def __init__(self, credentials=None, headers=None, auth=None, session=None, request_callback=None, response_callback=None):
+    def __init__(self, headers=None, auth=None, session=None, request_callback=None, response_callback=None):
         if headers:
             headers = {key.lower(): value for key, value in headers.items()}
         if session is None:
@@ -318,12 +318,6 @@ def __init__(self, credentials=None, headers=None, auth=None, session=None, requ
         if not getattr(session.auth, 'allow_cookies', False):
             session.cookies.set_policy(BlockAll())
 
-        if credentials is not None:
-            warnings.warn(
-                "The 'credentials' argument is now deprecated in favor of 'auth'.",
-                DeprecationWarning
-            )
-            auth = DomainCredentials(credentials)
         if request_callback is not None or response_callback is not None:
             warnings.warn(
                 "The 'request_callback' and 'response_callback' arguments are now deprecated. "

From b0eb95c1a22b6ef349e0207b314b492cb27bf8ff Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 30 Jan 2018 14:30:22 +0000
Subject: [PATCH 04/60] Drop HTTP request_callback and response_callback in
 favor of custom sessions

---
 coreapi/transports/http.py | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/coreapi/transports/http.py b/coreapi/transports/http.py
index 0b13b03..3bee6c0 100644
--- a/coreapi/transports/http.py
+++ b/coreapi/transports/http.py
@@ -308,7 +308,7 @@ def _decode_result(response, decoders, force_codec=False):
 class HTTPTransport(BaseTransport):
     schemes = ['http', 'https']
 
-    def __init__(self, headers=None, auth=None, session=None, request_callback=None, response_callback=None):
+    def __init__(self, headers=None, auth=None, session=None):
         if headers:
             headers = {key.lower(): value for key, value in headers.items()}
         if session is None:
@@ -318,15 +318,6 @@ def __init__(self, headers=None, auth=None, session=None, request_callback=None,
         if not getattr(session.auth, 'allow_cookies', False):
             session.cookies.set_policy(BlockAll())
 
-        if request_callback is not None or response_callback is not None:
-            warnings.warn(
-                "The 'request_callback' and 'response_callback' arguments are now deprecated. "
-                "Use a custom 'session' instance instead.",
-                DeprecationWarning
-            )
-            session.mount('https://', CallbackAdapter(request_callback, response_callback))
-            session.mount('http://', CallbackAdapter(request_callback, response_callback))
-
         self._headers = itypes.Dict(headers or {})
         self._session = session
 

From ad00b0a273bd0a781c21f4d70f2e32840d9c8f54 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 30 Jan 2018 14:33:44 +0000
Subject: [PATCH 05/60] Drop unused import

---
 coreapi/transports/http.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/coreapi/transports/http.py b/coreapi/transports/http.py
index 3bee6c0..f8268b6 100644
--- a/coreapi/transports/http.py
+++ b/coreapi/transports/http.py
@@ -11,7 +11,6 @@
 import itypes
 import mimetypes
 import uritemplate
-import warnings
 
 
 Params = collections.namedtuple('Params', ['path', 'query', 'data', 'files'])

From 15dcdc9cbde6015963977814da205c22c89d55a9 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 30 Jan 2018 15:58:30 +0000
Subject: [PATCH 06/60] Removing data from documents. Drop 'Array'.

---
 coreapi/__init__.py        |   4 +-
 coreapi/codecs/corejson.py |  10 +---
 coreapi/codecs/display.py  |  13 +----
 coreapi/codecs/python.py   |  12 +---
 coreapi/document.py        |  20 +------
 coreapi/transports/http.py |   9 +--
 tests/test_document.py     | 109 +------------------------------------
 7 files changed, 13 insertions(+), 164 deletions(-)

diff --git a/coreapi/__init__.py b/coreapi/__init__.py
index 92ac890..0e1f79b 100644
--- a/coreapi/__init__.py
+++ b/coreapi/__init__.py
@@ -1,12 +1,12 @@
 # coding: utf-8
 from coreapi import auth, codecs, exceptions, transports, utils
 from coreapi.client import Client
-from coreapi.document import Array, Document, Link, Object, Error, Field
+from coreapi.document import Document, Link, Object, Error, Field
 
 
 __version__ = '2.3.3'
 __all__ = [
-    'Array', 'Document', 'Link', 'Object', 'Error', 'Field',
+    'Document', 'Link', 'Object', 'Error', 'Field',
     'Client',
     'auth', 'codecs', 'exceptions', 'transports', 'utils',
 ]
diff --git a/coreapi/codecs/corejson.py b/coreapi/codecs/corejson.py
index 92facc4..4d6f75b 100644
--- a/coreapi/codecs/corejson.py
+++ b/coreapi/codecs/corejson.py
@@ -3,7 +3,7 @@
 from coreapi.codecs.base import BaseCodec
 from coreapi.compat import force_bytes, string_types, urlparse
 from coreapi.compat import COMPACT_SEPARATORS, VERBOSE_SEPARATORS
-from coreapi.document import Document, Link, Array, Object, Error, Field
+from coreapi.document import Document, Link, Object, Error, Field
 from coreapi.exceptions import ParseError
 import coreschema
 import json
@@ -222,9 +222,6 @@ def _document_to_primitive(node, base_url=None):
             for key, value in node.items()
         ])
 
-    elif isinstance(node, Array):
-        return [_document_to_primitive(value) for value in node]
-
     return node
 
 
@@ -284,11 +281,6 @@ def _primitive_to_document(data, base_url=None):
         content = _get_content(data, base_url=base_url)
         return Object(content)
 
-    elif isinstance(data, list):
-        # Array
-        content = [_primitive_to_document(item, base_url) for item in data]
-        return Array(content)
-
     # String, Integer, Number, Boolean, null.
     return data
 
diff --git a/coreapi/codecs/display.py b/coreapi/codecs/display.py
index 250e0cc..1dfa8cb 100644
--- a/coreapi/codecs/display.py
+++ b/coreapi/codecs/display.py
@@ -4,7 +4,7 @@
 from __future__ import unicode_literals
 from coreapi.codecs.base import BaseCodec
 from coreapi.compat import console_style, string_types
-from coreapi.document import Document, Link, Array, Object, Error
+from coreapi.document import Document, Link, Object, Error
 import json
 
 
@@ -76,17 +76,6 @@ def _to_plaintext(node, indent=0, base_url=None, colorize=False, extra_offset=No
 
         return head if (not body) else head + '\n' + body
 
-    elif isinstance(node, Array):
-        head_indent = '    ' * indent
-        body_indent = '    ' * (indent + 1)
-
-        body = ',\n'.join([
-            body_indent + _to_plaintext(value, indent + 1, base_url=base_url, colorize=colorize)
-            for value in node
-        ])
-
-        return '[]' if (not body) else '[\n' + body + '\n' + head_indent + ']'
-
     elif isinstance(node, Link):
         return (
             colorize_keys('link(') +
diff --git a/coreapi/codecs/python.py b/coreapi/codecs/python.py
index 6feec4e..c1e34ac 100644
--- a/coreapi/codecs/python.py
+++ b/coreapi/codecs/python.py
@@ -3,7 +3,7 @@
 # It may move into a utility function in the future.
 from __future__ import unicode_literals
 from coreapi.codecs.base import BaseCodec
-from coreapi.document import Document, Link, Array, Object, Error, Field
+from coreapi.document import Document, Link, Object, Error, Field
 
 
 def _to_repr(node):
@@ -31,11 +31,6 @@ def _to_repr(node):
             for key, value in node.items()
         ])
 
-    elif isinstance(node, Array):
-        return '[%s]' % ', '.join([
-            _to_repr(value) for value in node
-        ])
-
     elif isinstance(node, Link):
         args = "url=%s" % repr(node.url)
         if node.action:
@@ -71,10 +66,7 @@ class PythonCodec(BaseCodec):
     media_type = 'text/python'
 
     def encode(self, document, **options):
-        # Object and Array only have the class name wrapper if they
-        # are the outermost element.
+        # Object only has the class name wrapper if it is the outermost element.
         if isinstance(document, Object):
             return 'Object(%s)' % _to_repr(document)
-        elif isinstance(document, Array):
-            return 'Array(%s)' % _to_repr(document)
         return _to_repr(document)
diff --git a/coreapi/document.py b/coreapi/document.py
index dd498dc..f625999 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -8,8 +8,6 @@
 def _to_immutable(value):
     if isinstance(value, dict):
         return Object(value)
-    elif isinstance(value, list):
-        return Array(value)
     return value
 
 
@@ -169,20 +167,6 @@ def links(self):
         ])
 
 
-class Array(itypes.List):
-    """
-    An immutable list type container.
-    """
-    def __init__(self, *args):
-        self._data = [_to_immutable(value) for value in list(*args)]
-
-    def __repr__(self):
-        return _repr(self)
-
-    def __str__(self):
-        return _str(self)
-
-
 class Link(itypes.Object):
     """
     Links represent the actions that a client may perform.
@@ -295,8 +279,10 @@ def title(self):
     def get_messages(self):
         messages = []
         for value in self.values():
-            if isinstance(value, Array):
+            if isinstance(value, list):
                 messages += [
                     item for item in value if isinstance(item, string_types)
                 ]
+            elif isinstance(value, string_types):
+                messages += [value]
         return messages
diff --git a/coreapi/transports/http.py b/coreapi/transports/http.py
index f8268b6..c593532 100644
--- a/coreapi/transports/http.py
+++ b/coreapi/transports/http.py
@@ -3,7 +3,7 @@
 from collections import OrderedDict
 from coreapi import exceptions, utils
 from coreapi.compat import cookiejar, urlparse
-from coreapi.document import Document, Object, Link, Array, Error
+from coreapi.document import Document, Object, Error
 from coreapi.transports.base import BaseTransport
 from coreapi.utils import guess_filename, is_file, File
 import collections
@@ -242,13 +242,6 @@ def _coerce_to_error_content(node):
             (key, _coerce_to_error_content(value))
             for key, value in node.data.items()
         ])
-    elif isinstance(node, Array):
-        # Strip Links from Arrays.
-        return [
-            _coerce_to_error_content(item)
-            for item in node
-            if not isinstance(item, Link)
-        ]
     return node
 
 
diff --git a/tests/test_document.py b/tests/test_document.py
index c985fa9..b9185f6 100644
--- a/tests/test_document.py
+++ b/tests/test_document.py
@@ -1,6 +1,6 @@
 # coding: utf-8
 from coreapi import Client
-from coreapi import Array, Document, Object, Link, Error, Field
+from coreapi import Document, Object, Link, Error, Field
 from coreapi.exceptions import LinkLookupError
 import pytest
 
@@ -13,7 +13,6 @@ def doc():
         content={
             'integer': 123,
             'dict': {'key': 'value'},
-            'list': [1, 2, 3],
             'link': Link(
                 url='/',
                 action='post',
@@ -28,11 +27,6 @@ def obj():
     return Object({'key': 'value', 'nested': {'abc': 123}})
 
 
-@pytest.fixture
-def array():
-    return Array([{'a': 1}, {'b': 2}, {'c': 3}])
-
-
 @pytest.fixture
 def link():
     return Link(
@@ -95,23 +89,6 @@ def test_object_does_not_support_key_deletion(obj):
         del obj['key']
 
 
-# Arrays are immutable.
-
-def test_array_does_not_support_item_assignment(array):
-    with pytest.raises(TypeError):
-        array[1] = 456
-
-
-def test_array_does_not_support_property_assignment(array):
-    with pytest.raises(TypeError):
-        array.integer = 456
-
-
-def test_array_does_not_support_item_deletion(array):
-    with pytest.raises(TypeError):
-        del array[1]
-
-
 # Links are immutable.
 
 def test_link_does_not_support_property_assignment():
@@ -134,10 +111,6 @@ def test_document_dictionaries_coerced_to_objects(doc):
     assert isinstance(doc['dict'], Object)
 
 
-def test_document_lists_coerced_to_arrays(doc):
-    assert isinstance(doc['list'], Array)
-
-
 # The `delete` and `set` methods return new instances.
 
 def test_document_delete(doc):
@@ -172,48 +145,6 @@ def test_object_set(obj):
         assert obj[key] is new[key]
 
 
-def test_array_delete(array):
-    new = array.delete(1)
-    assert array is not new
-    assert len(new) == len(array) - 1
-    assert new[0] is array[0]
-    assert new[1] is array[2]
-
-
-def test_array_set(array):
-    new = array.set(1, 456)
-    assert array is not new
-    assert len(new) == len(array)
-    assert new[0] is array[0]
-    assert new[1] == 456
-    assert new[2] is array[2]
-
-
-# The `delete_in` and `set_in` functions return new instances.
-
-def test_delete_in():
-    nested = Object({'key': [{'abc': 123}, {'def': 456}], 'other': 0})
-
-    assert nested.delete_in(['key', 0]) == {'key': [{'def': 456}], 'other': 0}
-    assert nested.delete_in(['key']) == {'other': 0}
-    assert nested.delete_in([]) is None
-
-
-def test_set_in():
-    nested = Object({'key': [{'abc': 123}, {'def': 456}], 'other': 0})
-    insert = Object({'xyz': 789})
-
-    assert (
-        nested.set_in(['key', 0], insert) ==
-        {'key': [{'xyz': 789}, {'def': 456}], 'other': 0}
-    )
-    assert (
-        nested.set_in(['key'], insert) ==
-        {'key': {'xyz': 789}, 'other': 0}
-    )
-    assert nested.set_in([], insert) == {'xyz': 789}
-
-
 # Container types have a uniquely identifying representation.
 
 def test_document_repr(doc):
@@ -221,7 +152,6 @@ def test_document_repr(doc):
         "Document(url='http://example.org', title='Example', content={"
         "'dict': {'key': 'value'}, "
         "'integer': 123, "
-        "'list': [1, 2, 3], "
         "'nested': {'child': Link(url='/123')}, "
         "'link': Link(url='/', action='post', "
         "fields=['optional', Field('required', required=True, location='path')])"
@@ -235,11 +165,6 @@ def test_object_repr(obj):
     assert eval(repr(obj)) == obj
 
 
-def test_array_repr(array):
-    assert repr(array) == "Array([{'a': 1}, {'b': 2}, {'c': 3}])"
-    assert eval(repr(array)) == array
-
-
 def test_link_repr(link):
     assert repr(link) == "Link(url='/', action='post', fields=[Field('required', required=True), 'optional'])"
     assert eval(repr(link)) == link
@@ -259,11 +184,6 @@ def test_document_str(doc):
                 key: "value"
             }
             integer: 123
-            list: [
-                1,
-                2,
-                3
-            ]
             nested: {
                 child()
             }
@@ -291,22 +211,6 @@ def test_object_str(obj):
     """)
 
 
-def test_array_str(array):
-    assert str(array) == _dedent("""
-        [
-            {
-                a: 1
-            },
-            {
-                b: 2
-            },
-            {
-                c: 3
-            }
-        ]
-    """)
-
-
 def test_link_str(link):
     assert str(link) == "link(required, [optional])"
 
@@ -314,9 +218,7 @@ def test_link_str(link):
 def test_error_str(error):
     assert str(error) == _dedent("""
         <Error>
-            messages: [
-                "failed"
-            ]
+            messages: ["failed"]
     """)
 
 
@@ -340,7 +242,6 @@ def test_document_equality(doc):
     assert doc == {
         'integer': 123,
         'dict': {'key': 'value'},
-        'list': [1, 2, 3],
         'link': Link(
             url='/',
             action='post',
@@ -354,14 +255,10 @@ def test_object_equality(obj):
     assert obj == {'key': 'value', 'nested': {'abc': 123}}
 
 
-def test_array_equality(array):
-    assert array == [{'a': 1}, {'b': 2}, {'c': 3}]
-
-
 # Container types support len.
 
 def test_document_len(doc):
-    assert len(doc) == 5
+    assert len(doc) == 4
 
 
 def test_object_len(obj):

From f3c8ddef2a9c4aaedbdf10fd80c50d2a64ed6b39 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 31 Jan 2018 12:06:13 +0000
Subject: [PATCH 07/60] Drop CallbackAdapater. We don't use it anywhere. Could
 later farm it out to an external lib or snippet if we want.

---
 coreapi/transports/http.py | 17 -----------------
 1 file changed, 17 deletions(-)

diff --git a/coreapi/transports/http.py b/coreapi/transports/http.py
index c593532..18b61e2 100644
--- a/coreapi/transports/http.py
+++ b/coreapi/transports/http.py
@@ -62,23 +62,6 @@ def __call__(self, request):
         return request
 
 
-class CallbackAdapter(requests.adapters.HTTPAdapter):
-    """
-    Custom requests HTTP adapter, to support deprecated callback arguments.
-    """
-    def __init__(self, request_callback=None, response_callback=None):
-        self.request_callback = request_callback
-        self.response_callback = response_callback
-
-    def send(self, request, **kwargs):
-        if self.request_callback is not None:
-            self.request_callback(request)
-        response = super(CallbackAdapter, self).send(request, **kwargs)
-        if self.response_callback is not None:
-            self.response_callback(response)
-        return response
-
-
 def _get_method(action):
     if not action:
         return 'GET'

From 7d06d9329283bbaed5feae8564352a7394277ce7 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 31 Jan 2018 12:15:18 +0000
Subject: [PATCH 08/60] Drop DomainCredentials, now that we have proper auth
 classes

---
 coreapi/transports/http.py | 24 +-----------------------
 1 file changed, 1 insertion(+), 23 deletions(-)

diff --git a/coreapi/transports/http.py b/coreapi/transports/http.py
index 18b61e2..aa0fae6 100644
--- a/coreapi/transports/http.py
+++ b/coreapi/transports/http.py
@@ -2,7 +2,7 @@
 from __future__ import unicode_literals
 from collections import OrderedDict
 from coreapi import exceptions, utils
-from coreapi.compat import cookiejar, urlparse
+from coreapi.compat import cookiejar
 from coreapi.document import Document, Object, Error
 from coreapi.transports.base import BaseTransport
 from coreapi.utils import guess_filename, is_file, File
@@ -40,28 +40,6 @@ class BlockAll(cookiejar.CookiePolicy):
     rfc2965 = hide_cookie2 = False
 
 
-class DomainCredentials(requests.auth.AuthBase):
-    """
-    Custom auth class to support deprecated 'credentials' argument.
-    """
-    allow_cookies = False
-    credentials = None
-
-    def __init__(self, credentials=None):
-        self.credentials = credentials
-
-    def __call__(self, request):
-        if not self.credentials:
-            return request
-
-        # Include any authorization credentials relevant to this domain.
-        url_components = urlparse.urlparse(request.url)
-        host = url_components.hostname
-        if host in self.credentials:
-            request.headers['Authorization'] = self.credentials[host]
-        return request
-
-
 def _get_method(action):
     if not action:
         return 'GET'

From ced53cf0640d69b674706c7a9d54928d1744373b Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 31 Jan 2018 15:14:03 +0000
Subject: [PATCH 09/60] Refactor to use session.request

---
 coreapi/transports/http.py | 31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/coreapi/transports/http.py b/coreapi/transports/http.py
index aa0fae6..bdfe0b4 100644
--- a/coreapi/transports/http.py
+++ b/coreapi/transports/http.py
@@ -160,35 +160,35 @@ def _get_upload_headers(file_obj):
     }
 
 
-def _build_http_request(session, url, method, headers=None, encoding=None, params=empty_params):
+def _get_request_options(headers=None, encoding=None, params=empty_params):
     """
-    Make an HTTP request and return an HTTP response.
+    Returns a dictionary of keyword parameters to include when making
+    the outgoing request.
     """
-    opts = {
+    options = {
         "headers": headers or {}
     }
 
     if params.query:
-        opts['params'] = params.query
+        options['params'] = params.query
 
     if params.data or params.files:
         if encoding == 'application/json':
-            opts['json'] = params.data
+            options['json'] = params.data
         elif encoding == 'multipart/form-data':
-            opts['data'] = params.data
-            opts['files'] = ForceMultiPartDict(params.files)
+            options['data'] = params.data
+            options['files'] = ForceMultiPartDict(params.files)
         elif encoding == 'application/x-www-form-urlencoded':
-            opts['data'] = params.data
+            options['data'] = params.data
         elif encoding == 'application/octet-stream':
             if isinstance(params.data, File):
-                opts['data'] = params.data.content
+                options['data'] = params.data.content
             else:
-                opts['data'] = params.data
+                options['data'] = params.data
             upload_headers = _get_upload_headers(params.data)
-            opts['headers'].update(upload_headers)
+            headers.update(upload_headers)
 
-    request = requests.Request(method, url, **opts)
-    return session.prepare_request(request)
+    return options
 
 
 def _coerce_to_error_content(node):
@@ -287,9 +287,8 @@ def transition(self, link, decoders, params=None, force_codec=False):
         headers = _get_headers(url, decoders)
         headers.update(self.headers)
 
-        request = _build_http_request(session, url, method, headers, encoding, params)
-        settings = session.merge_environment_settings(request.url, None, None, None, None)
-        response = session.send(request, **settings)
+        options = _get_request_options(headers, encoding, params)
+        response = session.request(method, url, **options)
         result = _decode_result(response, decoders, force_codec)
 
         if isinstance(result, Error):

From 93946cd3112c41d71164e18cb531e9ad5102bcb7 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 31 Jan 2018 15:26:08 +0000
Subject: [PATCH 10/60] Drop unneccessary default parameters

---
 coreapi/transports/http.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/coreapi/transports/http.py b/coreapi/transports/http.py
index bdfe0b4..e6f5256 100644
--- a/coreapi/transports/http.py
+++ b/coreapi/transports/http.py
@@ -160,7 +160,7 @@ def _get_upload_headers(file_obj):
     }
 
 
-def _get_request_options(headers=None, encoding=None, params=empty_params):
+def _get_request_options(headers, encoding, params):
     """
     Returns a dictionary of keyword parameters to include when making
     the outgoing request.

From e99f71b1a9b2ffb9189906602dc6a089ae233410 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 31 Jan 2018 15:27:12 +0000
Subject: [PATCH 11/60] Move _guess_extension out of utils and into
 codes/download

---
 coreapi/codecs/download.py | 93 +++++++++++++++++++++++++++++++++++++-
 coreapi/utils.py           | 89 ------------------------------------
 2 files changed, 91 insertions(+), 91 deletions(-)

diff --git a/coreapi/codecs/download.py b/coreapi/codecs/download.py
index 0995690..8547c1a 100644
--- a/coreapi/codecs/download.py
+++ b/coreapi/codecs/download.py
@@ -1,13 +1,102 @@
 # coding: utf-8
 from coreapi.codecs.base import BaseCodec
 from coreapi.compat import urlparse
-from coreapi.utils import DownloadedFile, guess_extension
+from coreapi.utils import DownloadedFile
 import cgi
 import os
 import posixpath
 import tempfile
 
 
+def _guess_extension(content_type):
+    """
+    Python's `mimetypes.guess_extension` is no use because it simply returns
+    the first of an unordered set. We use the same set of media types here,
+    but take a reasonable preference on what extension to map to.
+    """
+    return {
+        'application/javascript': '.js',
+        'application/msword': '.doc',
+        'application/octet-stream': '.bin',
+        'application/oda': '.oda',
+        'application/pdf': '.pdf',
+        'application/pkcs7-mime': '.p7c',
+        'application/postscript': '.ps',
+        'application/vnd.apple.mpegurl': '.m3u',
+        'application/vnd.ms-excel': '.xls',
+        'application/vnd.ms-powerpoint': '.ppt',
+        'application/x-bcpio': '.bcpio',
+        'application/x-cpio': '.cpio',
+        'application/x-csh': '.csh',
+        'application/x-dvi': '.dvi',
+        'application/x-gtar': '.gtar',
+        'application/x-hdf': '.hdf',
+        'application/x-latex': '.latex',
+        'application/x-mif': '.mif',
+        'application/x-netcdf': '.nc',
+        'application/x-pkcs12': '.p12',
+        'application/x-pn-realaudio': '.ram',
+        'application/x-python-code': '.pyc',
+        'application/x-sh': '.sh',
+        'application/x-shar': '.shar',
+        'application/x-shockwave-flash': '.swf',
+        'application/x-sv4cpio': '.sv4cpio',
+        'application/x-sv4crc': '.sv4crc',
+        'application/x-tar': '.tar',
+        'application/x-tcl': '.tcl',
+        'application/x-tex': '.tex',
+        'application/x-texinfo': '.texinfo',
+        'application/x-troff': '.tr',
+        'application/x-troff-man': '.man',
+        'application/x-troff-me': '.me',
+        'application/x-troff-ms': '.ms',
+        'application/x-ustar': '.ustar',
+        'application/x-wais-source': '.src',
+        'application/xml': '.xml',
+        'application/zip': '.zip',
+        'audio/basic': '.au',
+        'audio/mpeg': '.mp3',
+        'audio/x-aiff': '.aif',
+        'audio/x-pn-realaudio': '.ra',
+        'audio/x-wav': '.wav',
+        'image/gif': '.gif',
+        'image/ief': '.ief',
+        'image/jpeg': '.jpe',
+        'image/png': '.png',
+        'image/svg+xml': '.svg',
+        'image/tiff': '.tiff',
+        'image/vnd.microsoft.icon': '.ico',
+        'image/x-cmu-raster': '.ras',
+        'image/x-ms-bmp': '.bmp',
+        'image/x-portable-anymap': '.pnm',
+        'image/x-portable-bitmap': '.pbm',
+        'image/x-portable-graymap': '.pgm',
+        'image/x-portable-pixmap': '.ppm',
+        'image/x-rgb': '.rgb',
+        'image/x-xbitmap': '.xbm',
+        'image/x-xpixmap': '.xpm',
+        'image/x-xwindowdump': '.xwd',
+        'message/rfc822': '.eml',
+        'text/css': '.css',
+        'text/csv': '.csv',
+        'text/html': '.html',
+        'text/plain': '.txt',
+        'text/richtext': '.rtx',
+        'text/tab-separated-values': '.tsv',
+        'text/x-python': '.py',
+        'text/x-setext': '.etx',
+        'text/x-sgml': '.sgml',
+        'text/x-vcard': '.vcf',
+        'text/xml': '.xml',
+        'video/mp4': '.mp4',
+        'video/mpeg': '.mpeg',
+        'video/quicktime': '.mov',
+        'video/webm': '.webm',
+        'video/x-msvideo': '.avi',
+        'video/x-sgi-movie': '.movie'
+    }.get(content_type, '')
+
+
 def _unique_output_path(path):
     """
     Given a path like '/a/b/c.txt'
@@ -69,7 +158,7 @@ def _get_filename_from_url(url, content_type=None):
     parsed = urlparse.urlparse(url)
     final_path_component = posixpath.basename(parsed.path.rstrip('/'))
     filename = _safe_filename(final_path_component)
-    suffix = guess_extension(content_type or '')
+    suffix = _guess_extension(content_type or '')
 
     if filename:
         if '.' not in filename:
diff --git a/coreapi/utils.py b/coreapi/utils.py
index fb7ade4..f39ed8a 100644
--- a/coreapi/utils.py
+++ b/coreapi/utils.py
@@ -54,95 +54,6 @@ def guess_filename(obj):
     return None
 
 
-def guess_extension(content_type):
-    """
-    Python's `mimetypes.guess_extension` is no use because it simply returns
-    the first of an unordered set. We use the same set of media types here,
-    but take a reasonable preference on what extension to map to.
-    """
-    return {
-        'application/javascript': '.js',
-        'application/msword': '.doc',
-        'application/octet-stream': '.bin',
-        'application/oda': '.oda',
-        'application/pdf': '.pdf',
-        'application/pkcs7-mime': '.p7c',
-        'application/postscript': '.ps',
-        'application/vnd.apple.mpegurl': '.m3u',
-        'application/vnd.ms-excel': '.xls',
-        'application/vnd.ms-powerpoint': '.ppt',
-        'application/x-bcpio': '.bcpio',
-        'application/x-cpio': '.cpio',
-        'application/x-csh': '.csh',
-        'application/x-dvi': '.dvi',
-        'application/x-gtar': '.gtar',
-        'application/x-hdf': '.hdf',
-        'application/x-latex': '.latex',
-        'application/x-mif': '.mif',
-        'application/x-netcdf': '.nc',
-        'application/x-pkcs12': '.p12',
-        'application/x-pn-realaudio': '.ram',
-        'application/x-python-code': '.pyc',
-        'application/x-sh': '.sh',
-        'application/x-shar': '.shar',
-        'application/x-shockwave-flash': '.swf',
-        'application/x-sv4cpio': '.sv4cpio',
-        'application/x-sv4crc': '.sv4crc',
-        'application/x-tar': '.tar',
-        'application/x-tcl': '.tcl',
-        'application/x-tex': '.tex',
-        'application/x-texinfo': '.texinfo',
-        'application/x-troff': '.tr',
-        'application/x-troff-man': '.man',
-        'application/x-troff-me': '.me',
-        'application/x-troff-ms': '.ms',
-        'application/x-ustar': '.ustar',
-        'application/x-wais-source': '.src',
-        'application/xml': '.xml',
-        'application/zip': '.zip',
-        'audio/basic': '.au',
-        'audio/mpeg': '.mp3',
-        'audio/x-aiff': '.aif',
-        'audio/x-pn-realaudio': '.ra',
-        'audio/x-wav': '.wav',
-        'image/gif': '.gif',
-        'image/ief': '.ief',
-        'image/jpeg': '.jpe',
-        'image/png': '.png',
-        'image/svg+xml': '.svg',
-        'image/tiff': '.tiff',
-        'image/vnd.microsoft.icon': '.ico',
-        'image/x-cmu-raster': '.ras',
-        'image/x-ms-bmp': '.bmp',
-        'image/x-portable-anymap': '.pnm',
-        'image/x-portable-bitmap': '.pbm',
-        'image/x-portable-graymap': '.pgm',
-        'image/x-portable-pixmap': '.ppm',
-        'image/x-rgb': '.rgb',
-        'image/x-xbitmap': '.xbm',
-        'image/x-xpixmap': '.xpm',
-        'image/x-xwindowdump': '.xwd',
-        'message/rfc822': '.eml',
-        'text/css': '.css',
-        'text/csv': '.csv',
-        'text/html': '.html',
-        'text/plain': '.txt',
-        'text/richtext': '.rtx',
-        'text/tab-separated-values': '.tsv',
-        'text/x-python': '.py',
-        'text/x-setext': '.etx',
-        'text/x-sgml': '.sgml',
-        'text/x-vcard': '.vcf',
-        'text/xml': '.xml',
-        'video/mp4': '.mp4',
-        'video/mpeg': '.mpeg',
-        'video/quicktime': '.mov',
-        'video/webm': '.webm',
-        'video/x-msvideo': '.avi',
-        'video/x-sgi-movie': '.movie'
-    }.get(content_type, '')
-
-
 if _TemporaryFileWrapper:
     # Ideally we subclass this so that we can present a custom representation.
     class DownloadedFile(_TemporaryFileWrapper):

From 61d4198347ce81bcc7e6993108135986cabca13a Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 13 Feb 2018 15:58:03 +0000
Subject: [PATCH 12/60] Drop 'Document.clone'

---
 coreapi/document.py    |  3 ---
 tests/test_document.py | 34 ----------------------------------
 2 files changed, 37 deletions(-)

diff --git a/coreapi/document.py b/coreapi/document.py
index f625999..7b249c3 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -79,9 +79,6 @@ def __init__(self, url=None, title=None, description=None, media_type=None, cont
         self._media_type = '' if (media_type is None) else media_type
         self._data = {key: _to_immutable(value) for key, value in content.items()}
 
-    def clone(self, data):
-        return self.__class__(self.url, self.title, self.description, self.media_type, data)
-
     def __iter__(self):
         items = sorted(self._data.items(), key=_key_sorting)
         return iter([key for key, value in items])
diff --git a/tests/test_document.py b/tests/test_document.py
index b9185f6..6b10f97 100644
--- a/tests/test_document.py
+++ b/tests/test_document.py
@@ -111,40 +111,6 @@ def test_document_dictionaries_coerced_to_objects(doc):
     assert isinstance(doc['dict'], Object)
 
 
-# The `delete` and `set` methods return new instances.
-
-def test_document_delete(doc):
-    new = doc.delete('integer')
-    assert doc is not new
-    assert set(new.keys()) == set(doc.keys()) - set(['integer'])
-    for key in new.keys():
-        assert doc[key] is new[key]
-
-
-def test_document_set(doc):
-    new = doc.set('integer', 456)
-    assert doc is not new
-    assert set(new.keys()) == set(doc.keys())
-    for key in set(new.keys()) - set(['integer']):
-        assert doc[key] is new[key]
-
-
-def test_object_delete(obj):
-    new = obj.delete('key')
-    assert obj is not new
-    assert set(new.keys()) == set(obj.keys()) - set(['key'])
-    for key in new.keys():
-        assert obj[key] is new[key]
-
-
-def test_object_set(obj):
-    new = obj.set('key', 456)
-    assert obj is not new
-    assert set(new.keys()) == set(obj.keys())
-    for key in set(new.keys()) - set(['key']):
-        assert obj[key] is new[key]
-
-
 # Container types have a uniquely identifying representation.
 
 def test_document_repr(doc):

From bc6aa9eb4f59ce6f393730a4970200eb0f291270 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 14 Feb 2018 13:01:32 +0000
Subject: [PATCH 13/60] Add typesys. Add OpenAPI, JSONSchema.

---
 coreapi/__init__.py           |   6 +-
 coreapi/codecs/__init__.py    |   7 +-
 coreapi/codecs/jsonschema.py  | 166 ++++++++++++++++
 coreapi/codecs/openapi.py     |  94 +++++++++
 coreapi/document.py           |  31 ++-
 coreapi/schemas/__init__.py   |   5 +
 coreapi/schemas/jsonschema.py |  32 +++
 coreapi/schemas/openapi.py    | 137 +++++++++++++
 coreapi/typesys.py            | 358 ++++++++++++++++++++++++++++++++++
 tests/codecs/test_openapi.py  | 170 ++++++++++++++++
 10 files changed, 992 insertions(+), 14 deletions(-)
 create mode 100644 coreapi/codecs/jsonschema.py
 create mode 100644 coreapi/codecs/openapi.py
 create mode 100644 coreapi/schemas/__init__.py
 create mode 100644 coreapi/schemas/jsonschema.py
 create mode 100644 coreapi/schemas/openapi.py
 create mode 100644 coreapi/typesys.py
 create mode 100644 tests/codecs/test_openapi.py

diff --git a/coreapi/__init__.py b/coreapi/__init__.py
index 0e1f79b..21ac6a9 100644
--- a/coreapi/__init__.py
+++ b/coreapi/__init__.py
@@ -1,12 +1,12 @@
 # coding: utf-8
-from coreapi import auth, codecs, exceptions, transports, utils
+from coreapi import auth, codecs, exceptions, transports, typesys, utils
 from coreapi.client import Client
 from coreapi.document import Document, Link, Object, Error, Field
 
 
-__version__ = '2.3.3'
+__version__ = '3.0.0'
 __all__ = [
     'Document', 'Link', 'Object', 'Error', 'Field',
     'Client',
-    'auth', 'codecs', 'exceptions', 'transports', 'utils',
+    'auth', 'codecs', 'exceptions', 'transports', 'typesys', 'utils',
 ]
diff --git a/coreapi/codecs/__init__.py b/coreapi/codecs/__init__.py
index 4fa6a1a..8c3596f 100644
--- a/coreapi/codecs/__init__.py
+++ b/coreapi/codecs/__init__.py
@@ -4,11 +4,14 @@
 from coreapi.codecs.display import DisplayCodec
 from coreapi.codecs.download import DownloadCodec
 from coreapi.codecs.jsondata import JSONCodec
+from coreapi.codecs.jsonschema import JSONSchemaCodec
+from coreapi.codecs.openapi import OpenAPICodec
 from coreapi.codecs.python import PythonCodec
 from coreapi.codecs.text import TextCodec
 
 
 __all__ = [
-    'BaseCodec', 'CoreJSONCodec', 'DisplayCodec',
-    'JSONCodec', 'PythonCodec', 'TextCodec', 'DownloadCodec'
+    'BaseCodec', 'CoreJSONCodec', 'DisplayCodec', 'JSONCodec',
+    'JSONSchemaCodec', 'OpenAPICodec', 'PythonCodec', 'TextCodec',
+    'DownloadCodec'
 ]
diff --git a/coreapi/codecs/jsonschema.py b/coreapi/codecs/jsonschema.py
new file mode 100644
index 0000000..eae034c
--- /dev/null
+++ b/coreapi/codecs/jsonschema.py
@@ -0,0 +1,166 @@
+from coreapi import typesys
+from coreapi.codecs.base import BaseCodec
+from coreapi.compat import COMPACT_SEPARATORS, VERBOSE_SEPARATORS, force_bytes
+from coreapi.exceptions import ParseError
+from coreapi.schemas import JSONSchema
+import collections
+import json
+
+
+class JSONSchemaCodec(BaseCodec):
+    media_type = 'application/schema+json'
+
+    def decode(self, bytestring, **options):
+        try:
+            data = json.loads(
+                bytestring.decode('utf-8'),
+                object_pairs_hook=collections.OrderedDict
+            )
+        except ValueError as exc:
+            raise ParseError('Malformed JSON. %s' % exc)
+        jsonschema = JSONSchema(data)
+        return self.decode_from_data_structure(jsonschema)
+
+    def decode_from_data_structure(self, struct):
+        attrs = {}
+
+        if '$ref' in struct:
+            if struct['$ref'] == '#':
+                return typesys.ref()
+            name = struct['$ref'].split('/')[-1]
+            return typesys.ref(name)
+
+        if struct['type'] == 'string':
+            if 'minLength' in struct:
+                attrs['min_length'] = struct['minLength']
+            if 'maxLength' in struct:
+                attrs['max_length'] = struct['maxLength']
+            if 'pattern' in struct:
+                attrs['pattern'] = struct['pattern']
+            if 'format' in struct:
+                attrs['format'] = struct['format']
+            return typesys.string(**attrs)
+
+        if struct['type'] in ['number', 'integer']:
+            if 'minimum' in struct:
+                attrs['minimum'] = struct['minimum']
+            if 'maximum' in struct:
+                attrs['maximum'] = struct['maximum']
+            if 'exclusiveMinimum' in struct:
+                attrs['exclusiveMinimum'] = struct['exclusiveMinimum']
+            if 'exclusiveMaximum' in struct:
+                attrs['exclusiveMaximum'] = struct['exclusiveMaximum']
+            if 'multipleOf' in struct:
+                attrs['multipleOf'] = struct['multipleOf']
+            if struct['type'] == 'integer':
+                return typesys.integer(**attrs)
+            return typesys.number(**attrs)
+
+        if struct['type'] == 'boolean':
+            return typesys.boolean()
+
+        if struct['type'] == 'object':
+            if 'properties' in struct:
+                attrs['properties'] = {
+                    key: self.decode_from_data_structure(value)
+                    for key, value in struct['properties'].items()
+                }
+            if 'required' in struct:
+                attrs['required'] = struct['required']
+            return typesys.obj(**attrs)
+
+        if struct['type'] == 'array':
+            if 'items' in struct:
+                attrs['items'] = self.decode_from_data_structure(struct['items'])
+            if 'additionalItems' in struct:
+                attrs['additional_items'] = struct['additionalItems']
+            if 'minItems' in struct:
+                attrs['min_items'] = struct['minItems']
+            if 'maxItems' in struct:
+                attrs['max_items'] = struct['maxItems']
+            if 'uniqueItems' in struct:
+                attrs['unique_items'] = struct['uniqueItems']
+            return typesys.array(**attrs)
+
+    def encode(self, cls, **options):
+        struct = self.encode_to_data_structure(cls)
+        indent = options.get('indent')
+        if indent:
+            kwargs = {
+                'ensure_ascii': False,
+                'indent': 4,
+                'separators': VERBOSE_SEPARATORS
+            }
+        else:
+            kwargs = {
+                'ensure_ascii': False,
+                'indent': None,
+                'separators': COMPACT_SEPARATORS
+            }
+        return force_bytes(json.dumps(struct, **kwargs))
+
+    def encode_to_data_structure(self, cls):
+        if issubclass(cls, typesys.String):
+            value = {'type': 'string'}
+            if cls.max_length is not None:
+                value['maxLength'] = cls.max_length
+            if cls.min_length is not None:
+                value['minLength'] = cls.min_length
+            if cls.pattern is not None:
+                value['pattern'] = cls.pattern
+            if cls.format is not None:
+                value['format'] = cls.format
+            return value
+
+        if issubclass(cls, typesys.NumericType):
+            if issubclass(cls, typesys.Integer):
+                value = {'type': 'integer'}
+            else:
+                value = {'type': 'number'}
+
+            if cls.minimum is not None:
+                value['minimum'] = cls.minimum
+            if cls.maximum is not None:
+                value['maximum'] = cls.maximum
+            if cls.exclusive_minimum:
+                value['exclusiveMinimum'] = cls.exclusive_minimum
+            if cls.exclusive_maximum:
+                value['exclusiveMaximum'] = cls.exclusive_maximum
+            if cls.multiple_of is not None:
+                value['multipleOf'] = cls.multiple_of
+            return value
+
+        if issubclass(cls, typesys.Boolean):
+            return {'type': 'boolean'}
+
+        if issubclass(cls, typesys.Object):
+            value = {'type': 'object'}
+            if cls.properties:
+                value['properties'] = {
+                    key: self.encode_to_data_structure(value)
+                    for key, value in cls.properties.items()
+                }
+            if cls.required:
+                value['required'] = cls.required
+            return value
+
+        if issubclass(cls, typesys.Array):
+            value = {'type': 'array'}
+            if cls.items is not None:
+                value['items'] = self.encode_to_data_structure(cls.items)
+            if cls.additional_items:
+                value['additionalItems'] = cls.additional_items
+            if cls.min_items is not None:
+                value['minItems'] = cls.min_items
+            if cls.max_items is not None:
+                value['maxItems'] = cls.max_items
+            if cls.unique_items is not None:
+                value['uniqueItems'] = cls.unique_items
+            return value
+
+        if issubclass(cls, typesys.Ref):
+            if not cls.to:
+                return {'$ref': '#'}
+            return {'$ref': '#/definitions/%s' % cls.to}
+
+        raise Exception('Cannot encode class %s' % cls)
diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
new file mode 100644
index 0000000..732bda1
--- /dev/null
+++ b/coreapi/codecs/openapi.py
@@ -0,0 +1,94 @@
+from coreapi.codecs import BaseCodec, JSONSchemaCodec
+from coreapi.document import Document, Link, Field
+from coreapi.schemas import OpenAPI
+import yaml
+
+
+METHODS = [
+    'get', 'put', 'post', 'delete', 'options', 'head', 'patch', 'trace'
+]
+
+
+class OpenAPICodec(BaseCodec):
+    media_type = 'application/vnd.oai.openapi'
+    format = 'openapi'
+
+    def decode(self, bytestring, **options):
+        data = yaml.safe_load(bytestring)
+        openapi = OpenAPI(data)
+        title = openapi.lookup(['info', 'title'])
+        description = openapi.lookup(['info', 'description'])
+        url = openapi.lookup(['servers', 0, 'url'])
+        content = self.get_links(openapi)
+        return Document(title=title, description=description, url=url, content=content)
+
+    def get_links(self, openapi):
+        """
+        Return all the links in the document, layed out by tag and operationId.
+        """
+        content = {}
+
+        for path, path_info in openapi.get('paths', {}).items():
+            operations = {
+                key: path_info[key] for key in path_info
+                if key in METHODS
+            }
+            for operation, operation_info in operations.items():
+                operationId = operation_info.get('operationId')
+                tag = operation_info.lookup(['tags', 0])
+                if not operationId:
+                    continue
+
+                link = self.get_link(path, path_info, operation, operation_info)
+                if tag is None:
+                    content[operationId] = link
+                else:
+                    if tag in content:
+                        content[tag][operationId] = link
+                    else:
+                        content[tag] = {operationId: link}
+
+        return content
+
+    def get_link(self, path, path_info, operation, operation_info):
+        """
+        Return a single link in the document.
+        """
+        title = operation_info.get('summary')
+        description = operation_info.get('description')
+        parameters = path_info.get('parameters', [])
+        parameters += operation_info.get('parameters', [])
+
+        fields = [
+            self.get_field(parameter)
+            for parameter in parameters
+        ]
+
+        return Link(
+            url=path,
+            action=operation,
+            title=title,
+            description=description,
+            fields=fields
+        )
+
+    def get_field(self, parameter):
+        """
+        Return a single field in a link.
+        """
+        name = parameter.get('name')
+        location = parameter.get('in')
+        description = parameter.get('description')
+        required = parameter.get('required', False)
+        schema = parameter.get('schema')
+
+        if schema is not None:
+            schema = JSONSchemaCodec().decode_from_data_structure(schema)
+
+        return Field(
+            name=name,
+            location=location,
+            description=description,
+            required=required,
+            schema=schema
+        )
diff --git a/coreapi/document.py b/coreapi/document.py
index 7b249c3..f2773cc 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -1,6 +1,6 @@
 # coding: utf-8
 from __future__ import unicode_literals
-from collections import OrderedDict, namedtuple
+from collections import OrderedDict
 from coreapi.compat import string_types
 import itypes
 
@@ -40,14 +40,6 @@ def _key_sorting(item):
     return (0, key)
 
 
-# The field class, as used by Link objects:
-
-# NOTE: 'type', 'description' and 'example' are now deprecated,
-#       in favor of 'schema'.
-Field = namedtuple('Field', ['name', 'required', 'location', 'schema', 'description', 'type', 'example'])
-Field.__new__.__defaults__ = (False, '', None, None, None, None)
-
-
 # The Core API primitives:
 
 class Document(itypes.Dict):
@@ -238,6 +230,27 @@ def __str__(self):
         return _str(self)
 
 
+class Field(object):
+    def __init__(self, name, required=False, location='', schema=None, description=None, example=None):
+        self.name = name
+        self.required = required
+        self.location = location
+        self.schema = schema
+        self.description = description
+        self.example = example
+
+    def __eq__(self, other):
+        return (
+            isinstance(other, Field) and
+            self.name == other.name and
+            self.required == other.required and
+            self.location == other.location and
+            self.description == other.description and
+            self.schema.__class__ == other.schema.__class__ and
+            self.example == other.example
+        )
+
+
 class Error(itypes.Dict):
     def __init__(self, title=None, content=None):
         data = {} if (content is None) else content
diff --git a/coreapi/schemas/__init__.py b/coreapi/schemas/__init__.py
new file mode 100644
index 0000000..16e7864
--- /dev/null
+++ b/coreapi/schemas/__init__.py
@@ -0,0 +1,5 @@
+from coreapi.schemas.jsonschema import JSONSchema
+from coreapi.schemas.openapi import OpenAPI
+
+
+__all__ = ['JSONSchema', 'OpenAPI']
diff --git a/coreapi/schemas/jsonschema.py b/coreapi/schemas/jsonschema.py
new file mode 100644
index 0000000..b408d0f
--- /dev/null
+++ b/coreapi/schemas/jsonschema.py
@@ -0,0 +1,32 @@
+from coreapi import typesys
+
+
+class JSONSchema(typesys.Object):
+    properties = {
+        '$ref': typesys.string(),
+        'type': typesys.string(),
+
+        # String
+        'minLength': typesys.integer(minimum=0, default=0),
+        'maxLength': typesys.integer(minimum=0),
+        'pattern': typesys.string(format='regex'),
+        'format': typesys.string(),
+
+        # Numeric
+        'minimum': typesys.number(),
+        'maximum': typesys.number(),
+        'exclusiveMinimum': typesys.boolean(default=False),
+        'exclusiveMaximum': typesys.boolean(default=False),
+        'multipleOf': typesys.number(minimum=0.0, exclusive_minimum=True),
+
+        # Object
+        'properties': typesys.obj(),  # TODO: typesys.ref('JSONSchema'),
+        'required': typesys.array(items=typesys.string(), min_items=1, unique=True),
+
+        # Array
+        'items': typesys.obj(),  # TODO: typesys.ref('JSONSchema'),
+        'additionalItems': typesys.boolean(),
+        'minItems': typesys.integer(minimum=0),
+        'maxItems': typesys.integer(minimum=0),
+        'uniqueItems': typesys.boolean(),
+    }
diff --git a/coreapi/schemas/openapi.py b/coreapi/schemas/openapi.py
new file mode 100644
index 0000000..d572628
--- /dev/null
+++ b/coreapi/schemas/openapi.py
@@ -0,0 +1,137 @@
+from coreapi import typesys
+from coreapi.schemas import JSONSchema
+
+
+class Contact(typesys.Object):
+    properties = {
+        'name': typesys.string(),
+        'url': typesys.string(format='url'),
+        'email': typesys.string(format='email')
+    }
+
+
+class License(typesys.Object):
+    properties = {
+        'name': typesys.string(),
+        'url': typesys.string(format='url')
+    }
+    required = ['name']
+
+
+class Info(typesys.Object):
+    properties = {
+        'title': typesys.string(),
+        'description': typesys.string(format='textarea'),
+        'termsOfService': typesys.string(format='url'),
+        'contact': Contact,
+        'license': License,
+        'version': typesys.string()
+    }
+    required = ['title', 'version']
+
+
+class ServerVariable(typesys.Object):
+    properties = {
+        'enum': typesys.array(items=typesys.string()),
+        'default': typesys.string(),
+        'description': typesys.string(format='textarea')
+    }
+    required = ['default']
+
+
+class Server(typesys.Object):
+    properties = {
+        'url': typesys.string(),
+        'description': typesys.string(format='textarea'),
+        'variables': typesys.obj(additional_properties=ServerVariable)
+    }
+    required = ['url']
+
+
+class ExternalDocs(typesys.Object):
+    properties = {
+        'description': typesys.string(format='textarea'),
+        'url': typesys.string(format='url')
+    }
+    required = ['url']
+
+
+class SecurityRequirement(typesys.Object):
+    additional_properties = typesys.array(items=typesys.string())
+
+
+class Parameter(typesys.Object):
+    properties = {
+        'name': typesys.string(),
+        'in': typesys.enum(enum=['query', 'header', 'path', 'cookie']),
+        'description': typesys.string(format='textarea'),
+        'required': typesys.boolean(),
+        'deprecated': typesys.boolean(),
+        'allowEmptyValue': typesys.boolean(),
+        'schema': JSONSchema,
+        # TODO: Other fields
+    }
+    required = ['name', 'in']
+
+
+class Operation(typesys.Object):
+    properties = {
+        'tags': typesys.array(items=typesys.string()),
+        'summary': typesys.string(),
+        'description': typesys.string(format='textarea'),
+        'externalDocs': ExternalDocs,
+        'operationId': typesys.string(),
+        'parameters': typesys.array(items=Parameter),  # Parameter | ReferenceObject
+        # TODO: 'requestBody'
+        # TODO: 'responses'
+        # TODO: 'callbacks'
+        'deprecated': typesys.boolean(),
+        'security': SecurityRequirement,
+        'servers': typesys.array(items=Server)
+    }
+
+
+class Path(typesys.Object):
+    properties = {
+        'summary': typesys.string(),
+        'description': typesys.string(format='textarea'),
+        'get': Operation,
+        'put': Operation,
+        'post': Operation,
+        'delete': Operation,
+        'options': Operation,
+        'head': Operation,
+        'patch': Operation,
+        'trace': Operation,
+        'servers': typesys.array(items=Server),
+        'parameters': typesys.array(items=Parameter)  # TODO: Parameter | ReferenceObject
+    }
+
+
+class Paths(typesys.Object):
+    pattern_properties = {
+        '^/': Path  # TODO: Path | ReferenceObject
+    }
+
+
+class Tag(typesys.Object):
+    properties = {
+        'name': typesys.string(),
+        'description': typesys.string(format='textarea'),
+        'externalDocs': ExternalDocs
+    }
+    required = ['name']
+
+
+class OpenAPI(typesys.Object):
+    properties = {
+        'openapi': typesys.string(),
+        'info': Info,
+        'servers': typesys.array(items=Server),
+        'paths': Paths,
+        # TODO: 'components': ...,
+        'security': SecurityRequirement,
+        'tags': typesys.array(items=Tag),
+        'externalDocs': ExternalDocs
+    }
+    required = ['openapi', 'info']
diff --git a/coreapi/typesys.py b/coreapi/typesys.py
new file mode 100644
index 0000000..167739a
--- /dev/null
+++ b/coreapi/typesys.py
@@ -0,0 +1,358 @@
+import re
+# from typing import Any, Dict, List, Optional, Tuple, Union, overload  # noqa
+
+
+# TODO: Error on unknown attributes
+# TODO: allow_blank?
+# TODO: format (check type at start and allow, coerce, .native)
+# TODO: default=empty
+# TODO: check 'required' exists in 'properties'
+# TODO: smarter ordering
+# TODO: extra_properties=False by default
+# TODO: inf, -inf, nan
+# TODO: Overriding errors
+# TODO: Blank booleans as False?
+
+
+class ValidationError(Exception):
+    def __init__(self, detail):
+        self.detail = detail
+        super(ValidationError, self).__init__(detail)
+
+
+class String(str):
+    errors = {
+        'type': 'Must be a string.',
+        'blank': 'Must not be blank.',
+        'max_length': 'Must have no more than {max_length} characters.',
+        'min_length': 'Must have at least {min_length} characters.',
+        'pattern': 'Must match the pattern /{pattern}/.',
+        'format': 'Must be a valid {format}.',
+    }
+    max_length = None  # type: int
+    min_length = None  # type: int
+    pattern = None  # type: str
+    format = None  # type: Any
+    trim_whitespace = True
+
+    def __new__(cls, value):
+        value = str.__new__(cls, value)
+
+        if cls.trim_whitespace:
+            value = value.strip()
+
+        if cls.min_length is not None:
+            if len(value) < cls.min_length:
+                if cls.min_length == 1:
+                    cls.error('blank')
+                else:
+                    cls.error('min_length')
+
+        if cls.max_length is not None:
+            if len(value) > cls.max_length:
+                cls.error('max_length')
+
+        if cls.pattern is not None:
+            if not re.search(cls.pattern, value):
+                cls.error('pattern')
+
+        return value
+
+    @classmethod
+    def error(cls, code):
+        message = cls.errors[code].format(**cls.__dict__)
+        raise ValidationError(message)  # from None
+
+
+class NumericType(object):
+    """
+    Base class for both `Number` and `Integer`.
+    """
+    numeric_type = None  # type: type
+    errors = {
+        'type': 'Must be a valid number.',
+        'minimum': 'Must be greater than or equal to {minimum}.',
+        'exclusive_minimum': 'Must be greater than {minimum}.',
+        'maximum': 'Must be less than or equal to {maximum}.',
+        'exclusive_maximum': 'Must be less than {maximum}.',
+        'multiple_of': 'Must be a multiple of {multiple_of}.',
+    }
+    minimum = None  # type: Union[float, int]
+    maximum = None  # type: Union[float, int]
+    exclusive_minimum = False
+    exclusive_maximum = False
+    multiple_of = None  # type: Union[float, int]
+
+    def __new__(cls, value):
+        try:
+            value = cls.numeric_type.__new__(cls, value)
+        except (TypeError, ValueError):
+            cls.error('type')
+
+        if cls.minimum is not None:
+            if cls.exclusive_minimum:
+                if value <= cls.minimum:
+                    cls.error('exclusive_minimum')
+            else:
+                if value < cls.minimum:
+                    cls.error('minimum')
+
+        if cls.maximum is not None:
+            if cls.exclusive_maximum:
+                if value >= cls.maximum:
+                    cls.error('exclusive_maximum')
+            else:
+                if value > cls.maximum:
+                    cls.error('maximum')
+
+        if cls.multiple_of is not None:
+            if isinstance(cls.multiple_of, float):
+                failed = not (value * (1 / cls.multiple_of)).is_integer()
+            else:
+                failed = value % cls.multiple_of
+            if failed:
+                cls.error('multiple_of')
+
+        return value
+
+    @classmethod
+    def error(cls, code):
+        message = cls.errors[code].format(**cls.__dict__)
+        raise ValidationError(message)  # from None
+
+
+class Number(NumericType, float):
+    numeric_type = float
+
+
+class Integer(NumericType, int):
+    numeric_type = int
+
+
+class Boolean(object):
+    native_type = bool
+    errors = {
+        'type': 'Must be a valid boolean.'
+    }
+
+    def __new__(cls, value):
+        if isinstance(value, str):
+            try:
+                return {
+                    'true': True,
+                    'false': False,
+                    '1': True,
+                    '0': False
+                }[value.lower()]
+            except KeyError:
+                cls.error('type')
+        return bool(value)
+
+    @classmethod
+    def error(cls, code):
+        message = cls.errors[code].format(**cls.__dict__)
+        raise ValidationError(message)  # from None
+
+
+class Enum(str):
+    errors = {
+        'enum': 'Must be a valid choice.',
+        'exact': 'Must be {exact}.'
+    }
+    enum = []  # type: List[str]
+
+    def __new__(cls, value):
+        if value not in cls.enum:
+            if len(cls.enum) == 1:
+                cls.error('exact')
+            cls.error('enum')
+        return value
+
+    @classmethod
+    def error(cls, code):
+        message = cls.errors[code].format(**cls.__dict__)
+        raise ValidationError(message)  # from None
+
+
+class Object(dict):
+    errors = {
+        'type': 'Must be an object.',
+        'invalid_key': 'Object keys must be strings.',
+        'required': 'This field is required.',
+    }
+    properties = {}  # type: Dict[str, type]
+    pattern_properties = None  # type: Dict[str, type]
+    additional_properties = None  # type: type
+    required = []
+
+    def __init__(self, value):
+        try:
+            value = dict(value)
+        except TypeError:
+            self.error('type')
+
+        # Ensure all property keys are strings.
+        errors = {}
+        if any(not isinstance(key, str) for key in value.keys()):
+            self.error('invalid_key')
+
+        # Properties
+        for key, child_schema in self.properties.items():
+            try:
+                item = value.pop(key)
+            except KeyError:
+                if key in self.required:
+                    errors[key] = self.error_message('required')
+            else:
+                # Coerce value into the given schema type if needed.
+                if isinstance(item, child_schema):
+                    self[key] = item
+                else:
+                    try:
+                        self[key] = child_schema(item)
+                    except ValidationError as exc:
+                        errors[key] = exc.detail
+
+        # Pattern properties
+        if self.pattern_properties is not None:
+            for key in list(value.keys()):
+                for pattern, child_schema in self.pattern_properties.items():
+                    if re.search(pattern, key):
+                        item = value.pop(key)
+                        try:
+                            self[key] = child_schema(item)
+                        except ValidationError as exc:
+                            errors[key] = exc.detail
+
+        # Additional properties
+        if self.additional_properties is not None:
+            child_schema = self.additional_properties
+            for key in list(value.keys()):
+                item = value.pop(key)
+                try:
+                    self[key] = child_schema(item)
+                except ValidationError as exc:
+                    errors[key] = exc.detail
+
+        if errors:
+            raise ValidationError(errors)
+
+    def lookup(self, keys, default=None):
+        try:
+            item = self[keys[0]]
+        except KeyError:
+            return default
+
+        if len(keys) == 1:
+            return item
+        return item.lookup(keys[1:], default)
+
+    def error(self, code):
+        message = self.errors[code].format(**self.__dict__)
+        raise ValidationError(message)  # from None
+
+    def error_message(self, code):
+        return self.errors[code].format(**self.__dict__)
+
+
+class Array(list):
+    errors = {
+        'type': 'Must be a list.',
+        'min_items': 'Not enough items.',
+        'max_items': 'Too many items.',
+        'unique_items': 'This item is not unique.',
+    }
+    items = None  # type: Union[type, List[type]]
+    additional_items = False  # type: bool
+    min_items = None  # type: Optional[int]
+    max_items = None  # type: Optional[int]
+    unique_items = False  # type: bool
+
+    def __init__(self, value):
+        try:
+            value = list(value)
+        except TypeError:
+            self.error('type')
+
+        if isinstance(self.items, list) and len(self.items) > 1:
+            if len(value) < len(self.items):
+                self.error('min_items')
+            elif len(value) > len(self.items) and not self.additional_items:
+                self.error('max_items')
+
+        if self.min_items is not None and len(value) < self.min_items:
+            self.error('min_items')
+        elif self.max_items is not None and len(value) > self.max_items:
+            self.error('max_items')
+
+        # Ensure all items are of the right type.
+        errors = {}
+        if self.unique_items:
+            seen_items = set()
+
+        for pos, item in enumerate(value):
+            try:
+                if isinstance(self.items, list):
+                    if pos < len(self.items):
+                        item = self.items[pos](item)
+                elif self.items is not None:
+                    item = self.items(item)
+
+                if self.unique_items:
+                    if item in seen_items:
+                        self.error('unique_items')
+                    else:
+                        seen_items.add(item)
+
+                self.append(item)
+            except ValidationError as exc:
+                errors[pos] = exc.detail
+
+        if errors:
+            raise ValidationError(errors)
+
+    def lookup(self, keys, default=None):
+        try:
+            item = self[keys[0]]
+        except (TypeError, IndexError):
+            return default
+
+        if len(keys) == 1:
+            return item
+        return item.lookup(keys[1:], default)
+
+    def error(self, code):
+        message = self.errors[code].format(**self.__dict__)
+        raise ValidationError(message)  # from None
+
+
+def string(**kwargs):
+    return type('String', (String,), kwargs)
+
+
+def integer(**kwargs):
+    return type('Integer', (Integer,), kwargs)
+
+
+def number(**kwargs):
+    return type('Number', (Number,), kwargs)
+
+
+def boolean(**kwargs):
+    return type('Boolean', (Boolean,), kwargs)
+
+
+def enum(**kwargs):
+    return type('Enum', (Enum,), kwargs)
+
+
+def array(**kwargs):
+    return type('Array', (Array,), kwargs)
+
+
+def obj(**kwargs):
+    return type('Object', (Object,), kwargs)
+
+
+# def ref(to=''):
+#     return type('Ref', (Ref,), {'to': to})
diff --git a/tests/codecs/test_openapi.py b/tests/codecs/test_openapi.py
new file mode 100644
index 0000000..cf9c3b2
--- /dev/null
+++ b/tests/codecs/test_openapi.py
@@ -0,0 +1,170 @@
+from coreapi import typesys
+from coreapi.codecs import OpenAPICodec
+from coreapi.document import Document, Link, Field
+import pytest
+
+
+@pytest.fixture
+def openapi_codec():
+    return OpenAPICodec()
+
+
+@pytest.fixture
+def petstore_schema():
+    return '''
+openapi: "3.0.0"
+info:
+  version: 1.0.0
+  title: Swagger Petstore
+  license:
+    name: MIT
+servers:
+  - url: http://petstore.swagger.io/v1
+paths:
+  /pets:
+    get:
+      summary: List all pets
+      operationId: listPets
+      tags:
+        - pets
+      parameters:
+        - name: limit
+          in: query
+          description: How many items to return at one time (max 100)
+          required: false
+          schema:
+            type: integer
+            format: int32
+      responses:
+        '200':
+          description: An paged array of pets
+          headers:
+            x-next:
+              description: A link to the next page of responses
+              schema:
+                type: string
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Pets"
+        default:
+          description: unexpected error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+    post:
+      summary: Create a pet
+      operationId: createPets
+      tags:
+        - pets
+      responses:
+        '201':
+          description: Null response
+        default:
+          description: unexpected error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+  /pets/{petId}:
+    get:
+      summary: Info for a specific pet
+      operationId: showPetById
+      tags:
+        - pets
+      parameters:
+        - name: petId
+          in: path
+          required: true
+          description: The id of the pet to retrieve
+          schema:
+            type: string
+      responses:
+        '200':
+          description: Expected response to a valid request
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Pets"
+        default:
+          description: unexpected error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+components:
+  schemas:
+    Pet:
+      required:
+        - id
+        - name
+      properties:
+        id:
+          type: integer
+          format: int64
+        name:
+          type: string
+        tag:
+          type: string
+    Pets:
+      type: array
+      items:
+        $ref: "#/components/schemas/Pet"
+    Error:
+      required:
+        - code
+        - message
+      properties:
+        code:
+          type: integer
+          format: int32
+        message:
+          type: string
+'''
+
+
+def test_openapi(openapi_codec, petstore_schema):
+    doc = openapi_codec.decode(petstore_schema)
+    expected = Document(
+        title='Swagger Petstore',
+        url='http://petstore.swagger.io/v1',
+        content={
+            'pets': {
+                'listPets': Link(
+                    action='get',
+                    url='/pets',
+                    title='List all pets',
+                    fields=[
+                        Field(
+                            name='limit',
+                            location='query',
+                            description='How many items to return at one time (max 100)',
+                            required=False,
+                            schema=typesys.integer(format='int32')
+                        )
+                    ]
+                ),
+                'createPets': Link(
+                    action='post',
+                    url='/pets',
+                    title='Create a pet'
+                ),
+                'showPetById': Link(
+                    action='get',
+                    url='/pets/{petId}',
+                    title='Info for a specific pet',
+                    fields=[
+                        Field(
+                            name='petId',
+                            location='path',
+                            description='The id of the pet to retrieve',
+                            required=True,
+                            schema=typesys.string()
+                        )
+                    ]
+                )
+            }
+        }
+    )
+    assert doc == expected

From df8696645a86e52a683b9e691c928b9902798631 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 14 Feb 2018 13:33:40 +0000
Subject: [PATCH 14/60] .errors always a classmethod

---
 coreapi/typesys.py | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index 167739a..5eb5ece 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -247,12 +247,14 @@ def lookup(self, keys, default=None):
             return item
         return item.lookup(keys[1:], default)
 
-    def error(self, code):
-        message = self.errors[code].format(**self.__dict__)
+    @classmethod
+    def error(cls, code):
+        message = cls.errors[code].format(**cls.__dict__)
         raise ValidationError(message)  # from None
 
-    def error_message(self, code):
-        return self.errors[code].format(**self.__dict__)
+    @classmethod
+    def error_message(cls, code):
+        return cls.errors[code].format(**cls.__dict__)
 
 
 class Array(list):
@@ -321,11 +323,17 @@ def lookup(self, keys, default=None):
             return item
         return item.lookup(keys[1:], default)
 
-    def error(self, code):
-        message = self.errors[code].format(**self.__dict__)
+    @classmethod
+    def error(cls, code):
+        message = cls.errors[code].format(**cls.__dict__)
         raise ValidationError(message)  # from None
 
 
+class Any(object):
+    def __new__(self, value):
+        return value
+
+
 def string(**kwargs):
     return type('String', (String,), kwargs)
 

From f106bd020d68af3ba02e350bb343add563ef7577 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 14 Feb 2018 13:34:33 +0000
Subject: [PATCH 15/60] Create absolute URLs for Links from OpenAPI

---
 coreapi/codecs/openapi.py    | 25 +++++++++++++++++--------
 coreapi/schemas/openapi.py   |  1 +
 tests/codecs/test_openapi.py |  6 +++---
 3 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
index 732bda1..c706148 100644
--- a/coreapi/codecs/openapi.py
+++ b/coreapi/codecs/openapi.py
@@ -1,4 +1,5 @@
 from coreapi.codecs import BaseCodec, JSONSchemaCodec
+from coreapi.compat import urlparse
 from coreapi.document import Document, Link, Field
 from coreapi.schemas import OpenAPI
 import yaml
@@ -18,11 +19,11 @@ def decode(self, bytestring, **options):
         openapi = OpenAPI(data)
         title = openapi.lookup(['info', 'title'])
         description = openapi.lookup(['info', 'description'])
-        url = openapi.lookup(['servers', 0, 'url'])
-        content = self.get_links(openapi)
-        return Document(title=title, description=description, url=url, content=content)
+        base_url = openapi.lookup(['servers', 0, 'url'])
+        content = self.get_links(openapi, base_url)
+        return Document(title=title, description=description, url=base_url, content=content)
 
-    def get_links(self, openapi):
+    def get_links(self, openapi, base_url):
         """
         Return all the links in the document, layed out by tag and operationId.
         """
@@ -39,7 +40,7 @@ def get_links(self, openapi):
                 if not operationId:
                     continue
 
-                link = self.get_link(path, path_info, operation, operation_info)
+                link = self.get_link(base_url, path, path_info, operation, operation_info)
                 if tag is None:
                     content[operationId] = link
                 else:
@@ -50,12 +51,18 @@ def get_links(self, openapi):
 
         return content
 
-    def get_link(self, path, path_info, operation, operation_info):
+    def get_link(self, base_url, path, path_info, operation, operation_info):
         """
         Return a single link in the document.
         """
         title = operation_info.get('summary')
         description = operation_info.get('description')
+
+        # Allow path info and operation info to override the base url.
+        base_url = path_info.lookup(['servers', 0, 'url'], default=base_url)
+        base_url = operation_info.lookup(['servers', 0, 'url'], default=base_url)
+
+        # Parameters are taken both from the path info, and from the operation.
         parameters = path_info.get('parameters', [])
         parameters += operation_info.get('parameters', [])
 
@@ -65,7 +72,7 @@ def get_link(self, path, path_info, operation, operation_info):
         ]
 
         return Link(
-            url=path,
+            url=urlparse.urljoin(base_url, path),
             action=operation,
             title=title,
             description=description,
@@ -81,6 +88,7 @@ def get_field(self, parameter):
         description = parameter.get('description')
         required = parameter.get('required', False)
         schema = parameter.get('schema')
+        example = parameter.get('example')
 
         if schema is not None:
             schema = JSONSchemaCodec().decode_from_data_structure(schema)
@@ -90,5 +98,6 @@ def get_field(self, parameter):
             location=location,
             description=description,
             required=required,
-            schema=schema
+            schema=schema,
+            example=example
         )
diff --git a/coreapi/schemas/openapi.py b/coreapi/schemas/openapi.py
index d572628..443370c 100644
--- a/coreapi/schemas/openapi.py
+++ b/coreapi/schemas/openapi.py
@@ -69,6 +69,7 @@ class Parameter(typesys.Object):
         'deprecated': typesys.boolean(),
         'allowEmptyValue': typesys.boolean(),
         'schema': JSONSchema,
+        'example': typesys.Any
         # TODO: Other fields
     }
     required = ['name', 'in']
diff --git a/tests/codecs/test_openapi.py b/tests/codecs/test_openapi.py
index cf9c3b2..da82094 100644
--- a/tests/codecs/test_openapi.py
+++ b/tests/codecs/test_openapi.py
@@ -133,7 +133,7 @@ def test_openapi(openapi_codec, petstore_schema):
             'pets': {
                 'listPets': Link(
                     action='get',
-                    url='/pets',
+                    url='http://petstore.swagger.io/pets',
                     title='List all pets',
                     fields=[
                         Field(
@@ -147,12 +147,12 @@ def test_openapi(openapi_codec, petstore_schema):
                 ),
                 'createPets': Link(
                     action='post',
-                    url='/pets',
+                    url='http://petstore.swagger.io/pets',
                     title='Create a pet'
                 ),
                 'showPetById': Link(
                     action='get',
-                    url='/pets/{petId}',
+                    url='http://petstore.swagger.io/pets/{petId}',
                     title='Info for a specific pet',
                     fields=[
                         Field(

From 6b3296abc71da4877bffb7853f8db69600a64e82 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 14 Feb 2018 13:59:28 +0000
Subject: [PATCH 16/60] Drop coreschema

---
 coreapi/codecs/corejson.py | 34 ++++++++++++++++++----------------
 coreapi/typesys.py         | 15 +++++++++++++++
 requirements.txt           |  1 -
 setup.py                   |  1 -
 tests/test_codecs.py       |  6 +++---
 5 files changed, 36 insertions(+), 21 deletions(-)

diff --git a/coreapi/codecs/corejson.py b/coreapi/codecs/corejson.py
index 4d6f75b..07345ec 100644
--- a/coreapi/codecs/corejson.py
+++ b/coreapi/codecs/corejson.py
@@ -1,5 +1,6 @@
 from __future__ import unicode_literals
 from collections import OrderedDict
+from coreapi import typesys
 from coreapi.codecs.base import BaseCodec
 from coreapi.compat import force_bytes, string_types, urlparse
 from coreapi.compat import COMPACT_SEPARATORS, VERBOSE_SEPARATORS
@@ -13,15 +14,14 @@
 # Just a naive first-pass at this point.
 
 SCHEMA_CLASS_TO_TYPE_ID = {
-    coreschema.Object: 'object',
-    coreschema.Array: 'array',
-    coreschema.Number: 'number',
-    coreschema.Integer: 'integer',
-    coreschema.String: 'string',
-    coreschema.Boolean: 'boolean',
-    coreschema.Null: 'null',
-    coreschema.Enum: 'enum',
-    coreschema.Anything: 'anything'
+    typesys.Object: 'object',
+    typesys.Array: 'array',
+    typesys.Number: 'number',
+    typesys.Integer: 'integer',
+    typesys.String: 'string',
+    typesys.Boolean: 'boolean',
+    typesys.Enum: 'enum',
+    typesys.Any: 'anything'
 }
 
 TYPE_ID_TO_SCHEMA_CLASS = {
@@ -32,14 +32,16 @@
 
 
 def encode_schema_to_corejson(schema):
-    if hasattr(schema, 'typename'):
-        type_id = schema.typename
+    for cls, type_id in SCHEMA_CLASS_TO_TYPE_ID.items():
+        if issubclass(schema, cls):
+            break
     else:
-        type_id = SCHEMA_CLASS_TO_TYPE_ID.get(schema.__class__, 'anything')
+        type_id = 'anything'
+
     retval = {
         '_type': type_id,
-        'title': schema.title,
-        'description': schema.description
+        'title': schema.title or '',
+        'description': schema.description or ''
     }
     if hasattr(schema, 'enum'):
         retval['enum'] = schema.enum
@@ -51,12 +53,12 @@ def decode_schema_from_corejson(data):
     title = _get_string(data, 'title')
     description = _get_string(data, 'description')
 
-    kwargs = {}
+    kwargs = {'title': title, 'description': description}
     if type_id == 'enum':
         kwargs['enum'] = _get_list(data, 'enum')
 
     schema_cls = TYPE_ID_TO_SCHEMA_CLASS.get(type_id, coreschema.Anything)
-    return schema_cls(title=title, description=description, **kwargs)
+    return type(schema_cls.__name__, (schema_cls,), kwargs)
 
 
 # Robust dictionary lookups, that always return an item of the correct
diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index 5eb5ece..befded6 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -29,6 +29,8 @@ class String(str):
         'pattern': 'Must match the pattern /{pattern}/.',
         'format': 'Must be a valid {format}.',
     }
+    title = None  # type: str
+    description = None  # type: str
     max_length = None  # type: int
     min_length = None  # type: int
     pattern = None  # type: str
@@ -77,6 +79,8 @@ class NumericType(object):
         'exclusive_maximum': 'Must be less than {maximum}.',
         'multiple_of': 'Must be a multiple of {multiple_of}.',
     }
+    title = None  # type: str
+    description = None  # type: str
     minimum = None  # type: Union[float, int]
     maximum = None  # type: Union[float, int]
     exclusive_minimum = False
@@ -134,6 +138,8 @@ class Boolean(object):
     errors = {
         'type': 'Must be a valid boolean.'
     }
+    title = None  # type: str
+    description = None  # type: str
 
     def __new__(cls, value):
         if isinstance(value, str):
@@ -159,6 +165,8 @@ class Enum(str):
         'enum': 'Must be a valid choice.',
         'exact': 'Must be {exact}.'
     }
+    title = None  # type: str
+    description = None  # type: str
     enum = []  # type: List[str]
 
     def __new__(cls, value):
@@ -180,6 +188,8 @@ class Object(dict):
         'invalid_key': 'Object keys must be strings.',
         'required': 'This field is required.',
     }
+    title = None  # type: str
+    description = None  # type: str
     properties = {}  # type: Dict[str, type]
     pattern_properties = None  # type: Dict[str, type]
     additional_properties = None  # type: type
@@ -264,6 +274,8 @@ class Array(list):
         'max_items': 'Too many items.',
         'unique_items': 'This item is not unique.',
     }
+    title = None  # type: str
+    description = None  # type: str
     items = None  # type: Union[type, List[type]]
     additional_items = False  # type: bool
     min_items = None  # type: Optional[int]
@@ -330,6 +342,9 @@ def error(cls, code):
 
 
 class Any(object):
+    title = None  # type: str
+    description = None  # type: str
+
     def __new__(self, value):
         return value
 
diff --git a/requirements.txt b/requirements.txt
index 71ddd11..4a7d2a8 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,4 @@
 # Package requirements
-coreschema
 itypes
 requests
 uritemplate
diff --git a/setup.py b/setup.py
index 7dabead..2fa32a5 100755
--- a/setup.py
+++ b/setup.py
@@ -63,7 +63,6 @@ def get_package_data(package):
     packages=get_packages('coreapi'),
     package_data=get_package_data('coreapi'),
     install_requires=[
-        'coreschema',
         'requests',
         'itypes',
         'uritemplate'
diff --git a/tests/test_codecs.py b/tests/test_codecs.py
index 2475293..170ef69 100644
--- a/tests/test_codecs.py
+++ b/tests/test_codecs.py
@@ -1,10 +1,10 @@
 # coding: utf-8
+from coreapi import typesys
 from coreapi.codecs import CoreJSONCodec
 from coreapi.codecs.corejson import _document_to_primitive, _primitive_to_document
 from coreapi.document import Document, Link, Error, Field
 from coreapi.exceptions import ParseError, NoCodecAvailable
 from coreapi.utils import negotiate_decoder, negotiate_encoder
-from coreschema import Enum, String
 import pytest
 
 
@@ -26,8 +26,8 @@ def doc():
                 url='http://example.org/',
                 fields=[
                     Field(name='noschema'),
-                    Field(name='string_example', schema=String()),
-                    Field(name='enum_example', schema=Enum(['a', 'b', 'c'])),
+                    Field(name='string_example', schema=typesys.string()),
+                    Field(name='enum_example', schema=typesys.enum(enum=['a', 'b', 'c'])),
                 ]),
             'nested': {'child': Link(url='http://example.org/123')},
             '_type': 'needs escaping'

From 86446895a4996494ea130b0179ba60f7cabaaf83 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 14 Feb 2018 16:39:02 +0000
Subject: [PATCH 17/60] Ordered schema representations. Support OpenAPI
 encoding.

---
 coreapi/codecs/jsonschema.py  |   4 +
 coreapi/codecs/openapi.py     | 137 ++++++++++++++++++++++++++++-
 coreapi/compat.py             |   8 ++
 coreapi/schemas/jsonschema.py |  41 ++++-----
 coreapi/schemas/openapi.py    | 161 +++++++++++++++++-----------------
 coreapi/typesys.py            |   6 +-
 tests/codecs/test_openapi.py  |  96 +++++++++++++++++++-
 7 files changed, 347 insertions(+), 106 deletions(-)

diff --git a/coreapi/codecs/jsonschema.py b/coreapi/codecs/jsonschema.py
index eae034c..cd2506e 100644
--- a/coreapi/codecs/jsonschema.py
+++ b/coreapi/codecs/jsonschema.py
@@ -52,6 +52,8 @@ def decode_from_data_structure(self, struct):
                 attrs['exclusiveMaximum'] = struct['exclusiveMaximum']
             if 'multipleOf' in struct:
                 attrs['multipleOf'] = struct['multipleOf']
+            if 'format' in struct:
+                attrs['format'] = struct['format']
             if struct['type'] == 'integer':
                 return typesys.integer(**attrs)
             return typesys.number(**attrs)
@@ -128,6 +130,8 @@ def encode_to_data_structure(self, cls):
                 value['exclusiveMaximum'] = cls.exclusive_maximum
             if cls.multiple_of is not None:
                 value['multipleOf'] = cls.multiple_of
+            if cls.format is not None:
+                value['format'] = cls.format
             return value
 
         if issubclass(cls, typesys.Boolean):
diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
index c706148..e819695 100644
--- a/coreapi/codecs/openapi.py
+++ b/coreapi/codecs/openapi.py
@@ -1,5 +1,5 @@
 from coreapi.codecs import BaseCodec, JSONSchemaCodec
-from coreapi.compat import urlparse
+from coreapi.compat import dict_type, urlparse
 from coreapi.document import Document, Link, Field
 from coreapi.schemas import OpenAPI
 import yaml
@@ -10,6 +10,80 @@
 ]
 
 
+def represent_odict(dump, tag, mapping, flow_style=None):
+    """Like BaseRepresenter.represent_mapping, but does not issue the sort().
+    """
+    value = []
+    node = yaml.MappingNode(tag, value, flow_style=flow_style)
+    if dump.alias_key is not None:
+        dump.represented_objects[dump.alias_key] = node
+    best_style = True
+    if hasattr(mapping, 'items'):
+        mapping = mapping.items()
+    for item_key, item_value in mapping:
+        node_key = dump.represent_data(item_key)
+        node_value = dump.represent_data(item_value)
+        if not (isinstance(node_key, yaml.ScalarNode) and not node_key.style):
+            best_style = False
+        if not (isinstance(node_value, yaml.ScalarNode) and not node_value.style):
+            best_style = False
+        value.append((node_key, node_value))
+    if flow_style is None:
+        if dump.default_flow_style is not None:
+            node.flow_style = dump.default_flow_style
+        else:
+            node.flow_style = best_style
+    return node
+
+
+def represent_list(dump, tag, sequence, flow_style=None):
+    value = []
+    node = yaml.SequenceNode(tag, value, flow_style=flow_style)
+    if dump.alias_key is not None:
+        dump.represented_objects[dump.alias_key] = node
+    best_style = True
+    for item in sequence:
+        node_item = dump.represent_data(item)
+        if not (isinstance(node_item, yaml.ScalarNode) and not node_item.style):
+            best_style = False
+        value.append(node_item)
+    if flow_style is None:
+        if dump.default_flow_style is not None:
+            node.flow_style = dump.default_flow_style
+        else:
+            node.flow_style = best_style
+    return node
+
+
+class CustomSafeDumper(yaml.SafeDumper):
+    def increase_indent(self, flow=False, indentless=False):
+        return super(CustomSafeDumper, self).increase_indent(flow, False)
+
+
+CustomSafeDumper.add_multi_representer(
+    dict_type,
+    lambda dumper, value: represent_odict(dumper, u'tag:yaml.org,2002:map', value)
+)
+CustomSafeDumper.add_multi_representer(
+    list,
+    lambda dumper, value: represent_list(dumper, u'tag:yaml.org,2002:seq', value)
+)
+
+
+def _relative_url(base_url, url):
+    """
+    Return a graceful link for a URL relative to a base URL.
+
+    * If the have the same scheme and hostname, return the path & query params.
+    * Otherwise return the full URL.
+    """
+    base_prefix = '%s://%s' % urlparse.urlparse(base_url or '')[0:2]
+    url_prefix = '%s://%s' % urlparse.urlparse(url or '')[0:2]
+    if base_prefix == url_prefix and url_prefix != '://':
+        return url[len(url_prefix):]
+    return url
+
+
 class OpenAPICodec(BaseCodec):
     media_type = 'application/vnd.oai.openapi'
     format = 'openapi'
@@ -101,3 +175,64 @@ def get_field(self, parameter):
             schema=schema,
             example=example
         )
+
+    def encode(self, document, **options):
+        paths = self.get_paths(document)
+        openapi = OpenAPI({
+            'openapi': '3.0.0',
+            'info': {
+                'version': '',
+                'title': document.title,
+                'description': document.description
+            },
+            'servers': [{
+                'url': document.url
+            }],
+            'paths': paths
+        })
+        return yaml.dump(openapi, Dumper=CustomSafeDumper, default_flow_style=False)
+
+    def get_paths(self, document):
+        paths = {}
+
+        for operation_id, link in document.links.items():
+            url = urlparse.urlparse(link.url)
+            if url.path not in paths:
+                paths[url.path] = {}
+            paths[url.path][link.action] = self.get_operation(link, operation_id)
+
+        for tag, links in document.data.items():
+            for operation_id, link in links.links.items():
+                url = urlparse.urlparse(link.url)
+                if url.path not in paths:
+                    paths[url.path] = {}
+                paths[url.path][link.action] = self.get_operation(link, operation_id, tag=tag)
+
+        return paths
+
+    def get_operation(self, link, operation_id, tag=None):
+        operation = {
+            'operationId': operation_id
+        }
+        if link.title:
+            operation['summary'] = link.title
+        if link.description:
+            operation['description'] = link.description
+        if tag:
+            operation['tags'] = [tag]
+        if link.fields:
+            operation['parameters'] = [self.get_parameter(field) for field in link.fields]
+        return operation
+
+    def get_parameter(self, field):
+        parameter = {
+            'name': field.name,
+            'in': field.location
+        }
+        if field.required:
+            parameter['required'] = True
+        if field.description:
+            parameter['description'] = field.description
+        if field.schema:
+            parameter['schema'] = JSONSchemaCodec().encode_to_data_structure(field.schema)
+        return parameter
diff --git a/coreapi/compat.py b/coreapi/compat.py
index 9890ec1..c56cb44 100644
--- a/coreapi/compat.py
+++ b/coreapi/compat.py
@@ -1,6 +1,8 @@
 # coding: utf-8
 
 import base64
+import collections
+import sys
 
 
 __all__ = [
@@ -51,6 +53,12 @@ def force_text(string):
     return string
 
 
+if sys.version_info < (3, 5):
+    dict_type = collections.OrderedDict
+else:
+    dict_type = dict
+
+
 try:
     import click
     console_style = click.style
diff --git a/coreapi/schemas/jsonschema.py b/coreapi/schemas/jsonschema.py
index b408d0f..1dacfc9 100644
--- a/coreapi/schemas/jsonschema.py
+++ b/coreapi/schemas/jsonschema.py
@@ -1,32 +1,33 @@
 from coreapi import typesys
+from coreapi.compat import dict_type
 
 
 class JSONSchema(typesys.Object):
-    properties = {
-        '$ref': typesys.string(),
-        'type': typesys.string(),
+    properties = dict_type([
+        ('$ref', typesys.string()),
+        ('type', typesys.string()),
 
         # String
-        'minLength': typesys.integer(minimum=0, default=0),
-        'maxLength': typesys.integer(minimum=0),
-        'pattern': typesys.string(format='regex'),
-        'format': typesys.string(),
+        ('minLength', typesys.integer(minimum=0, default=0)),
+        ('maxLength', typesys.integer(minimum=0)),
+        ('pattern', typesys.string(format='regex')),
+        ('format', typesys.string()),
 
         # Numeric
-        'minimum': typesys.number(),
-        'maximum': typesys.number(),
-        'exclusiveMinimum': typesys.boolean(default=False),
-        'exclusiveMaximum': typesys.boolean(default=False),
-        'multipleOf': typesys.number(minimum=0.0, exclusive_minimum=True),
+        ('minimum', typesys.number()),
+        ('maximum', typesys.number()),
+        ('exclusiveMinimum', typesys.boolean(default=False)),
+        ('exclusiveMaximum', typesys.boolean(default=False)),
+        ('multipleOf', typesys.number(minimum=0.0, exclusive_minimum=True)),
 
         # Object
-        'properties': typesys.obj(),  # TODO: typesys.ref('JSONSchema'),
-        'required': typesys.array(items=typesys.string(), min_items=1, unique=True),
+        ('properties', typesys.obj()),  # TODO: typesys.ref('JSONSchema'),
+        ('required', typesys.array(items=typesys.string(), min_items=1, unique=True)),
 
         # Array
-        'items': typesys.obj(),  # TODO: typesys.ref('JSONSchema'),
-        'additionalItems': typesys.boolean(),
-        'minItems': typesys.integer(minimum=0),
-        'maxItems': typesys.integer(minimum=0),
-        'uniqueItems': typesys.boolean(),
-    }
+        ('items', typesys.obj()),  # TODO: typesys.ref('JSONSchema'),
+        ('additionalItems', typesys.boolean()),
+        ('minItems', typesys.integer(minimum=0)),
+        ('maxItems', typesys.integer(minimum=0)),
+        ('uniqueItems', typesys.boolean()),
+    ])
diff --git a/coreapi/schemas/openapi.py b/coreapi/schemas/openapi.py
index 443370c..3940434 100644
--- a/coreapi/schemas/openapi.py
+++ b/coreapi/schemas/openapi.py
@@ -1,58 +1,59 @@
 from coreapi import typesys
+from coreapi.compat import dict_type
 from coreapi.schemas import JSONSchema
 
 
 class Contact(typesys.Object):
-    properties = {
-        'name': typesys.string(),
-        'url': typesys.string(format='url'),
-        'email': typesys.string(format='email')
-    }
+    properties = dict_type([
+        ('name', typesys.string()),
+        ('url', typesys.string(format='url')),
+        ('email', typesys.string(format='email'))
+    ])
 
 
 class License(typesys.Object):
-    properties = {
-        'name': typesys.string(),
-        'url': typesys.string(format='url')
-    }
+    properties = dict_type([
+        ('name', typesys.string()),
+        ('url', typesys.string(format='url'))
+    ])
     required = ['name']
 
 
 class Info(typesys.Object):
-    properties = {
-        'title': typesys.string(),
-        'description': typesys.string(format='textarea'),
-        'termsOfService': typesys.string(format='url'),
-        'contact': Contact,
-        'license': License,
-        'version': typesys.string()
-    }
+    properties = dict_type([
+        ('title', typesys.string()),
+        ('description', typesys.string(format='textarea')),
+        ('termsOfService', typesys.string(format='url')),
+        ('contact', Contact),
+        ('license', License),
+        ('version', typesys.string())
+    ])
     required = ['title', 'version']
 
 
 class ServerVariable(typesys.Object):
-    properties = {
-        'enum': typesys.array(items=typesys.string()),
-        'default': typesys.string(),
-        'description': typesys.string(format='textarea')
-    }
+    properties = dict_type([
+        ('enum', typesys.array(items=typesys.string())),
+        ('default', typesys.string()),
+        ('description', typesys.string(format='textarea'))
+    ])
     required = ['default']
 
 
 class Server(typesys.Object):
-    properties = {
-        'url': typesys.string(),
-        'description': typesys.string(format='textarea'),
-        'variables': typesys.obj(additional_properties=ServerVariable)
-    }
+    properties = dict_type([
+        ('url', typesys.string()),
+        ('description', typesys.string(format='textarea')),
+        ('variables', typesys.obj(additional_properties=ServerVariable))
+    ])
     required = ['url']
 
 
 class ExternalDocs(typesys.Object):
-    properties = {
-        'description': typesys.string(format='textarea'),
-        'url': typesys.string(format='url')
-    }
+    properties = dict_type([
+        ('description', typesys.string(format='textarea')),
+        ('url', typesys.string(format='url'))
+    ])
     required = ['url']
 
 
@@ -61,52 +62,52 @@ class SecurityRequirement(typesys.Object):
 
 
 class Parameter(typesys.Object):
-    properties = {
-        'name': typesys.string(),
-        'in': typesys.enum(enum=['query', 'header', 'path', 'cookie']),
-        'description': typesys.string(format='textarea'),
-        'required': typesys.boolean(),
-        'deprecated': typesys.boolean(),
-        'allowEmptyValue': typesys.boolean(),
-        'schema': JSONSchema,
-        'example': typesys.Any
+    properties = dict_type([
+        ('name', typesys.string()),
+        ('in', typesys.enum(enum=['query', 'header', 'path', 'cookie'])),
+        ('description', typesys.string(format='textarea')),
+        ('required', typesys.boolean()),
+        ('deprecated', typesys.boolean()),
+        ('allowEmptyValue', typesys.boolean()),
+        ('schema', JSONSchema),
+        ('example', typesys.Any)
         # TODO: Other fields
-    }
+    ])
     required = ['name', 'in']
 
 
 class Operation(typesys.Object):
-    properties = {
-        'tags': typesys.array(items=typesys.string()),
-        'summary': typesys.string(),
-        'description': typesys.string(format='textarea'),
-        'externalDocs': ExternalDocs,
-        'operationId': typesys.string(),
-        'parameters': typesys.array(items=Parameter),  # Parameter | ReferenceObject
+    properties = dict_type([
+        ('tags', typesys.array(items=typesys.string())),
+        ('summary', typesys.string()),
+        ('description', typesys.string(format='textarea')),
+        ('externalDocs', ExternalDocs),
+        ('operationId', typesys.string()),
+        ('parameters', typesys.array(items=Parameter)),  # Parameter | ReferenceObject
         # TODO: 'requestBody'
         # TODO: 'responses'
         # TODO: 'callbacks'
-        'deprecated': typesys.boolean(),
-        'security': SecurityRequirement,
-        'servers': typesys.array(items=Server)
-    }
+        ('deprecated', typesys.boolean()),
+        ('security', SecurityRequirement),
+        ('servers', typesys.array(items=Server))
+    ])
 
 
 class Path(typesys.Object):
-    properties = {
-        'summary': typesys.string(),
-        'description': typesys.string(format='textarea'),
-        'get': Operation,
-        'put': Operation,
-        'post': Operation,
-        'delete': Operation,
-        'options': Operation,
-        'head': Operation,
-        'patch': Operation,
-        'trace': Operation,
-        'servers': typesys.array(items=Server),
-        'parameters': typesys.array(items=Parameter)  # TODO: Parameter | ReferenceObject
-    }
+    properties = dict_type([
+        ('summary', typesys.string()),
+        ('description', typesys.string(format='textarea')),
+        ('get', Operation),
+        ('put', Operation),
+        ('post', Operation),
+        ('delete', Operation),
+        ('options', Operation),
+        ('head', Operation),
+        ('patch', Operation),
+        ('trace', Operation),
+        ('servers', typesys.array(items=Server)),
+        ('parameters', typesys.array(items=Parameter))  # TODO: Parameter | ReferenceObject
+    ])
 
 
 class Paths(typesys.Object):
@@ -116,23 +117,23 @@ class Paths(typesys.Object):
 
 
 class Tag(typesys.Object):
-    properties = {
-        'name': typesys.string(),
-        'description': typesys.string(format='textarea'),
-        'externalDocs': ExternalDocs
-    }
+    properties = dict_type([
+        ('name', typesys.string()),
+        ('description', typesys.string(format='textarea')),
+        ('externalDocs', ExternalDocs)
+    ])
     required = ['name']
 
 
 class OpenAPI(typesys.Object):
-    properties = {
-        'openapi': typesys.string(),
-        'info': Info,
-        'servers': typesys.array(items=Server),
-        'paths': Paths,
+    properties = dict_type([
+        ('openapi', typesys.string()),
+        ('info', Info),
+        ('servers', typesys.array(items=Server)),
+        ('paths', Paths),
         # TODO: 'components': ...,
-        'security': SecurityRequirement,
-        'tags': typesys.array(items=Tag),
-        'externalDocs': ExternalDocs
-    }
+        ('security', SecurityRequirement),
+        ('tags', typesys.array(items=Tag)),
+        ('externalDocs', ExternalDocs)
+    ])
     required = ['openapi', 'info']
diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index befded6..8f66679 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -1,3 +1,4 @@
+from coreapi.compat import dict_type
 import re
 # from typing import Any, Dict, List, Optional, Tuple, Union, overload  # noqa
 
@@ -86,6 +87,7 @@ class NumericType(object):
     exclusive_minimum = False
     exclusive_maximum = False
     multiple_of = None  # type: Union[float, int]
+    format = None
 
     def __new__(cls, value):
         try:
@@ -182,7 +184,7 @@ def error(cls, code):
         raise ValidationError(message)  # from None
 
 
-class Object(dict):
+class Object(dict_type):
     errors = {
         'type': 'Must be an object.',
         'invalid_key': 'Object keys must be strings.',
@@ -196,6 +198,8 @@ class Object(dict):
     required = []
 
     def __init__(self, value):
+        super(Object, self).__init__()
+
         try:
             value = dict(value)
         except TypeError:
diff --git a/tests/codecs/test_openapi.py b/tests/codecs/test_openapi.py
index da82094..95ba951 100644
--- a/tests/codecs/test_openapi.py
+++ b/tests/codecs/test_openapi.py
@@ -11,8 +11,7 @@ def openapi_codec():
 
 @pytest.fixture
 def petstore_schema():
-    return '''
-openapi: "3.0.0"
+    return '''openapi: "3.0.0"
 info:
   version: 1.0.0
   title: Swagger Petstore
@@ -120,11 +119,54 @@ def petstore_schema():
           type: integer
           format: int32
         message:
-          type: string
+          type: string'''
+
+
+@pytest.fixture
+def minimal_petstore_schema():
+    return '''openapi: 3.0.0
+info:
+  title: Swagger Petstore
+  description: ''
+  version: ''
+servers:
+  - url: http://petstore.swagger.io/v1
+paths:
+  /pets:
+    get:
+      tags:
+        - pets
+      summary: List all pets
+      operationId: listPets
+      parameters:
+        - name: limit
+          in: query
+          description: How many items to return at one time (max 100)
+          schema:
+            type: integer
+            format: int32
+    post:
+      tags:
+        - pets
+      summary: Create a pet
+      operationId: createPets
+  /pets/{petId}:
+    get:
+      tags:
+        - pets
+      summary: Info for a specific pet
+      operationId: showPetById
+      parameters:
+        - name: petId
+          in: path
+          description: The id of the pet to retrieve
+          required: true
+          schema:
+            type: string
 '''
 
 
-def test_openapi(openapi_codec, petstore_schema):
+def test_decode_openapi(openapi_codec, petstore_schema):
     doc = openapi_codec.decode(petstore_schema)
     expected = Document(
         title='Swagger Petstore',
@@ -168,3 +210,49 @@ def test_openapi(openapi_codec, petstore_schema):
         }
     )
     assert doc == expected
+
+
+def test_encode_openapi(openapi_codec, minimal_petstore_schema):
+    doc = Document(
+        title='Swagger Petstore',
+        url='http://petstore.swagger.io/v1',
+        content={
+            'pets': {
+                'listPets': Link(
+                    action='get',
+                    url='http://petstore.swagger.io/pets',
+                    title='List all pets',
+                    fields=[
+                        Field(
+                            name='limit',
+                            location='query',
+                            description='How many items to return at one time (max 100)',
+                            required=False,
+                            schema=typesys.integer(format='int32')
+                        )
+                    ]
+                ),
+                'createPets': Link(
+                    action='post',
+                    url='http://petstore.swagger.io/pets',
+                    title='Create a pet'
+                ),
+                'showPetById': Link(
+                    action='get',
+                    url='http://petstore.swagger.io/pets/{petId}',
+                    title='Info for a specific pet',
+                    fields=[
+                        Field(
+                            name='petId',
+                            location='path',
+                            description='The id of the pet to retrieve',
+                            required=True,
+                            schema=typesys.string()
+                        )
+                    ]
+                )
+            }
+        }
+    )
+    schema = openapi_codec.encode(doc)
+    assert schema == minimal_petstore_schema

From 325d032aff95a6667fc7fcd9774f5f1c221278b1 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 14 Feb 2018 16:40:02 +0000
Subject: [PATCH 18/60] Include yaml in requirements

---
 requirements.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/requirements.txt b/requirements.txt
index 4a7d2a8..651d676 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,6 +2,7 @@
 itypes
 requests
 uritemplate
+pyyaml
 
 # Testing requirements
 coverage

From 5984a337c3e7e95db69b0da6dd903456641d33d3 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 14 Feb 2018 16:45:03 +0000
Subject: [PATCH 19/60] Drop coreschema

---
 coreapi/codecs/corejson.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/coreapi/codecs/corejson.py b/coreapi/codecs/corejson.py
index 07345ec..cd1f000 100644
--- a/coreapi/codecs/corejson.py
+++ b/coreapi/codecs/corejson.py
@@ -6,7 +6,6 @@
 from coreapi.compat import COMPACT_SEPARATORS, VERBOSE_SEPARATORS
 from coreapi.document import Document, Link, Object, Error, Field
 from coreapi.exceptions import ParseError
-import coreschema
 import json
 
 
@@ -57,7 +56,7 @@ def decode_schema_from_corejson(data):
     if type_id == 'enum':
         kwargs['enum'] = _get_list(data, 'enum')
 
-    schema_cls = TYPE_ID_TO_SCHEMA_CLASS.get(type_id, coreschema.Anything)
+    schema_cls = TYPE_ID_TO_SCHEMA_CLASS.get(type_id, typesys.Any)
     return type(schema_cls.__name__, (schema_cls,), kwargs)
 
 

From 9444bc066aa865a8aa9dada5aa1d6675ae353eb1 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 14 Feb 2018 16:53:40 +0000
Subject: [PATCH 20/60] Preserve ordering of OpenAPI 'paths' across python
 versions

---
 coreapi/codecs/openapi.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
index e819695..75d51be 100644
--- a/coreapi/codecs/openapi.py
+++ b/coreapi/codecs/openapi.py
@@ -193,7 +193,7 @@ def encode(self, document, **options):
         return yaml.dump(openapi, Dumper=CustomSafeDumper, default_flow_style=False)
 
     def get_paths(self, document):
-        paths = {}
+        paths = dict_type()
 
         for operation_id, link in document.links.items():
             url = urlparse.urlparse(link.url)

From b3fa5c2b89c0046c86e8f09af4e6bad4fadf958d Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Thu, 15 Feb 2018 15:42:27 +0000
Subject: [PATCH 21/60] Default to JSON-flavoured OpenAPI

---
 coreapi/__init__.py          |   4 +-
 coreapi/codecs/openapi.py    | 138 +++++++------
 coreapi/compat.py            |  31 +++
 coreapi/document.py          |   9 +-
 coreapi/typesys.py           |   4 +-
 requirements.txt             |   1 -
 tests/codecs/test_openapi.py | 386 +++++++++++++++++++++--------------
 7 files changed, 355 insertions(+), 218 deletions(-)

diff --git a/coreapi/__init__.py b/coreapi/__init__.py
index 21ac6a9..2bef8bb 100644
--- a/coreapi/__init__.py
+++ b/coreapi/__init__.py
@@ -1,12 +1,12 @@
 # coding: utf-8
 from coreapi import auth, codecs, exceptions, transports, typesys, utils
 from coreapi.client import Client
-from coreapi.document import Document, Link, Object, Error, Field
+from coreapi.document import Document, Link, Object, Error, Field, Array
 
 
 __version__ = '3.0.0'
 __all__ = [
-    'Document', 'Link', 'Object', 'Error', 'Field',
+    'Document', 'Link', 'Object', 'Error', 'Field', 'Array',
     'Client',
     'auth', 'codecs', 'exceptions', 'transports', 'typesys', 'utils',
 ]
diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
index 75d51be..c4714b3 100644
--- a/coreapi/codecs/openapi.py
+++ b/coreapi/codecs/openapi.py
@@ -1,8 +1,9 @@
 from coreapi.codecs import BaseCodec, JSONSchemaCodec
-from coreapi.compat import dict_type, urlparse
+from coreapi.compat import VERBOSE_SEPARATORS, dict_type, urlparse
 from coreapi.document import Document, Link, Field
+from coreapi.exceptions import ParseError
 from coreapi.schemas import OpenAPI
-import yaml
+import json
 
 
 METHODS = [
@@ -10,64 +11,66 @@
 ]
 
 
-def represent_odict(dump, tag, mapping, flow_style=None):
-    """Like BaseRepresenter.represent_mapping, but does not issue the sort().
-    """
-    value = []
-    node = yaml.MappingNode(tag, value, flow_style=flow_style)
-    if dump.alias_key is not None:
-        dump.represented_objects[dump.alias_key] = node
-    best_style = True
-    if hasattr(mapping, 'items'):
-        mapping = mapping.items()
-    for item_key, item_value in mapping:
-        node_key = dump.represent_data(item_key)
-        node_value = dump.represent_data(item_value)
-        if not (isinstance(node_key, yaml.ScalarNode) and not node_key.style):
-            best_style = False
-        if not (isinstance(node_value, yaml.ScalarNode) and not node_value.style):
-            best_style = False
-        value.append((node_key, node_value))
-    if flow_style is None:
-        if dump.default_flow_style is not None:
-            node.flow_style = dump.default_flow_style
-        else:
-            node.flow_style = best_style
-    return node
-
-
-def represent_list(dump, tag, sequence, flow_style=None):
-    value = []
-    node = yaml.SequenceNode(tag, value, flow_style=flow_style)
-    if dump.alias_key is not None:
-        dump.represented_objects[dump.alias_key] = node
-    best_style = True
-    for item in sequence:
-        node_item = dump.represent_data(item)
-        if not (isinstance(node_item, yaml.ScalarNode) and not node_item.style):
-            best_style = False
-        value.append(node_item)
-    if flow_style is None:
-        if dump.default_flow_style is not None:
-            node.flow_style = dump.default_flow_style
-        else:
-            node.flow_style = best_style
-    return node
-
-
-class CustomSafeDumper(yaml.SafeDumper):
-    def increase_indent(self, flow=False, indentless=False):
-        return super(CustomSafeDumper, self).increase_indent(flow, False)
-
-
-CustomSafeDumper.add_multi_representer(
-    dict_type,
-    lambda dumper, value: represent_odict(dumper, u'tag:yaml.org,2002:map', value)
-)
-CustomSafeDumper.add_multi_representer(
-    list,
-    lambda dumper, value: represent_list(dumper, u'tag:yaml.org,2002:seq', value)
-)
+# def represent_odict(dump, tag, mapping, flow_style=None):
+#     """Like BaseRepresenter.represent_mapping, but does not issue the sort().
+#     """
+#     value = []
+#     node = yaml.MappingNode(tag, value, flow_style=flow_style)
+#     if dump.alias_key is not None:
+#         dump.represented_objects[dump.alias_key] = node
+#     best_style = True
+#     if hasattr(mapping, 'items'):
+#         mapping = mapping.items()
+#     for item_key, item_value in mapping:
+#         node_key = dump.represent_data(item_key)
+#         node_value = dump.represent_data(item_value)
+#         if not (isinstance(node_key, yaml.ScalarNode) and not node_key.style):
+#             best_style = False
+#         if not (isinstance(node_value, yaml.ScalarNode) and not node_value.style):
+#             best_style = False
+#         value.append((node_key, node_value))
+#     if flow_style is None:
+#         if dump.default_flow_style is not None:
+#             node.flow_style = dump.default_flow_style
+#         else:
+#             node.flow_style = best_style
+#     return node
+#
+#
+# def represent_list(dump, tag, sequence, flow_style=None):
+#     value = []
+#     node = yaml.SequenceNode(tag, value, flow_style=flow_style)
+#     if dump.alias_key is not None:
+#         dump.represented_objects[dump.alias_key] = node
+#     best_style = True
+#     for item in sequence:
+#         node_item = dump.represent_data(item)
+#         if not (isinstance(node_item, yaml.ScalarNode) and not node_item.style):
+#             best_style = False
+#         value.append(node_item)
+#     if flow_style is None:
+#         if dump.default_flow_style is not None:
+#             node.flow_style = dump.default_flow_style
+#         else:
+#             node.flow_style = best_style
+#     return node
+#
+#
+# class CustomSafeDumper(yaml.SafeDumper):
+#     def increase_indent(self, flow=False, indentless=False):
+#         return super(CustomSafeDumper, self).increase_indent(flow, False)
+#
+#
+# CustomSafeDumper.add_multi_representer(
+#     dict_type,
+#     lambda dumper, value: represent_odict(dumper, u'tag:yaml.org,2002:map', value)
+# )
+# CustomSafeDumper.add_multi_representer(
+#     list,
+#     lambda dumper, value: represent_list(dumper, u'tag:yaml.org,2002:seq', value)
+# )
+#
+# return yaml.dump(openapi, Dumper=CustomSafeDumper, default_flow_style=False)
 
 
 def _relative_url(base_url, url):
@@ -89,7 +92,11 @@ class OpenAPICodec(BaseCodec):
     format = 'openapi'
 
     def decode(self, bytestring, **options):
-        data = yaml.safe_load(bytestring)
+        try:
+            data = json.loads(bytestring.decode('utf-8'))
+        except ValueError as exc:
+            raise ParseError('Malformed JSON. %s' % exc)
+
         openapi = OpenAPI(data)
         title = openapi.lookup(['info', 'title'])
         description = openapi.lookup(['info', 'description'])
@@ -190,7 +197,14 @@ def encode(self, document, **options):
             }],
             'paths': paths
         })
-        return yaml.dump(openapi, Dumper=CustomSafeDumper, default_flow_style=False)
+
+        kwargs = {
+            'ensure_ascii': False,
+            'indent': 4,
+            'separators': VERBOSE_SEPARATORS
+        }
+
+        return json.dumps(openapi, **kwargs)
 
     def get_paths(self, document):
         paths = dict_type()
diff --git a/coreapi/compat.py b/coreapi/compat.py
index c56cb44..d4fd043 100644
--- a/coreapi/compat.py
+++ b/coreapi/compat.py
@@ -41,6 +41,37 @@ def b64encode(input_string):
         return base64.b64encode(input_string.encode('ascii')).decode('ascii')
 
 
+try:
+    import coreschema
+except ImportError:
+    # Temporary shim, to support 'coreschema' until it's fully deprecated.
+    def coreschema_to_typesys(item):
+        return item
+else:
+    def coreschema_to_typesys(item):
+        from coreapi import typesys
+
+        # We were only ever using the type and title/description,
+        # so we don't both to include the full set of keyword arguments here.
+        if isinstance(item, coreschema.String):
+            return typesys.string(title=item.title, description=item.description)
+        elif isinstance(item, coreschema.Integer):
+            return typesys.integer(title=item.title, description=item.description)
+        elif isinstance(item, coreschema.Number):
+            return typesys.number(title=item.title, description=item.description)
+        elif isinstance(item, coreschema.Boolean):
+            return typesys.boolean(title=item.title, description=item.description)
+        elif isinstance(item, coreschema.Enum):
+            return typesys.enum(title=item.title, description=item.description, enum=item.enum)
+        elif isinstance(item, coreschema.Array):
+            return typesys.array(title=item.title, description=item.description)
+        elif isinstance(item, coreschema.Object):
+            return typesys.obj(title=item.title, description=item.description)
+        elif isinstance(item, coreschema.Anything):
+            return typesys.any(title=item.title, description=item.description)
+
+        return item
+
 def force_bytes(string):
     if isinstance(string, string_types):
         return string.encode('utf-8')
diff --git a/coreapi/document.py b/coreapi/document.py
index f2773cc..70102fc 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -1,7 +1,7 @@
 # coding: utf-8
 from __future__ import unicode_literals
 from collections import OrderedDict
-from coreapi.compat import string_types
+from coreapi.compat import coreschema_to_typesys, string_types
 import itypes
 
 
@@ -235,7 +235,7 @@ def __init__(self, name, required=False, location='', schema=None, description=N
         self.name = name
         self.required = required
         self.location = location
-        self.schema = schema
+        self.schema = coreschema_to_typesys(schema)
         self.description = description
         self.example = example
 
@@ -296,3 +296,8 @@ def get_messages(self):
             elif isinstance(value, string_types):
                 messages += [value]
         return messages
+
+
+class Array(object):
+    def __init__(self):
+        assert False, 'Array is deprecated'
diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index 8f66679..d1d139a 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -1,4 +1,4 @@
-from coreapi.compat import dict_type
+from coreapi.compat import dict_type, string_types
 import re
 # from typing import Any, Dict, List, Optional, Tuple, Union, overload  # noqa
 
@@ -207,7 +207,7 @@ def __init__(self, value):
 
         # Ensure all property keys are strings.
         errors = {}
-        if any(not isinstance(key, str) for key in value.keys()):
+        if any(not isinstance(key, string_types) for key in value.keys()):
             self.error('invalid_key')
 
         # Properties
diff --git a/requirements.txt b/requirements.txt
index 651d676..4a7d2a8 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,7 +2,6 @@
 itypes
 requests
 uritemplate
-pyyaml
 
 # Testing requirements
 coverage
diff --git a/tests/codecs/test_openapi.py b/tests/codecs/test_openapi.py
index 95ba951..5ee1a93 100644
--- a/tests/codecs/test_openapi.py
+++ b/tests/codecs/test_openapi.py
@@ -11,159 +11,247 @@ def openapi_codec():
 
 @pytest.fixture
 def petstore_schema():
-    return '''openapi: "3.0.0"
-info:
-  version: 1.0.0
-  title: Swagger Petstore
-  license:
-    name: MIT
-servers:
-  - url: http://petstore.swagger.io/v1
-paths:
-  /pets:
-    get:
-      summary: List all pets
-      operationId: listPets
-      tags:
-        - pets
-      parameters:
-        - name: limit
-          in: query
-          description: How many items to return at one time (max 100)
-          required: false
-          schema:
-            type: integer
-            format: int32
-      responses:
-        '200':
-          description: An paged array of pets
-          headers:
-            x-next:
-              description: A link to the next page of responses
-              schema:
-                type: string
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/Pets"
-        default:
-          description: unexpected error
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/Error"
-    post:
-      summary: Create a pet
-      operationId: createPets
-      tags:
-        - pets
-      responses:
-        '201':
-          description: Null response
-        default:
-          description: unexpected error
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/Error"
-  /pets/{petId}:
-    get:
-      summary: Info for a specific pet
-      operationId: showPetById
-      tags:
-        - pets
-      parameters:
-        - name: petId
-          in: path
-          required: true
-          description: The id of the pet to retrieve
-          schema:
-            type: string
-      responses:
-        '200':
-          description: Expected response to a valid request
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/Pets"
-        default:
-          description: unexpected error
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/Error"
-components:
-  schemas:
-    Pet:
-      required:
-        - id
-        - name
-      properties:
-        id:
-          type: integer
-          format: int64
-        name:
-          type: string
-        tag:
-          type: string
-    Pets:
-      type: array
-      items:
-        $ref: "#/components/schemas/Pet"
-    Error:
-      required:
-        - code
-        - message
-      properties:
-        code:
-          type: integer
-          format: int32
-        message:
-          type: string'''
+    return '''{
+    "openapi": "3.0.0",
+    "info": {
+        "title": "Swagger Petstore",
+        "version": "1.0.0",
+        "license": {
+            "name": "MIT"
+        }
+    },
+    "servers": [
+        {
+            "url": "http://petstore.swagger.io/v1"
+        }
+    ],
+    "paths": {
+        "/pets": {
+            "get": {
+                "tags": [
+                    "pets"
+                ],
+                "summary": "List all pets",
+                "operationId": "listPets",
+                "parameters": [
+                    {
+                        "in": "query",
+                        "description": "How many items to return at one time (max 100)",
+                        "name": "limit",
+                        "schema": {
+                            "format": "int32",
+                            "type": "integer"
+                        },
+                        "required": false
+                    }
+                ],
+                "responses": {
+                    "200": {
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/Pets"
+                                }
+                            }
+                        },
+                        "description": "An paged array of pets",
+                        "headers": {
+                            "x-next": {
+                                "description": "A link to the next page of responses",
+                                "schema": {
+                                    "type": "string"
+                                }
+                            }
+                        }
+                    },
+                    "default": {
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/Error"
+                                }
+                            }
+                        },
+                        "description": "unexpected error"
+                    }
+                }
+            },
+            "post": {
+                "tags": [
+                    "pets"
+                ],
+                "summary": "Create a pet",
+                "operationId": "createPets",
+                "responses": {
+                    "201": {
+                        "description": "Null response"
+                    },
+                    "default": {
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/Error"
+                                }
+                            }
+                        },
+                        "description": "unexpected error"
+                    }
+                }
+            }
+        },
+        "/pets/{petId}": {
+            "get": {
+                "tags": [
+                    "pets"
+                ],
+                "summary": "Info for a specific pet",
+                "operationId": "showPetById",
+                "parameters": [
+                    {
+                        "in": "path",
+                        "description": "The id of the pet to retrieve",
+                        "name": "petId",
+                        "schema": {
+                            "type": "string"
+                        },
+                        "required": true
+                    }
+                ],
+                "responses": {
+                    "200": {
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/Pets"
+                                }
+                            }
+                        },
+                        "description": "Expected response to a valid request"
+                    },
+                    "default": {
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/Error"
+                                }
+                            }
+                        },
+                        "description": "unexpected error"
+                    }
+                }
+            }
+        }
+    },
+    "components": {
+        "schemas": {
+            "Error": {
+                "properties": {
+                    "code": {
+                        "format": "int32",
+                        "type": "integer"
+                    },
+                    "message": {
+                        "type": "string"
+                    }
+                },
+                "required": [
+                    "code",
+                    "message"
+                ]
+            },
+            "Pets": {
+                "items": {
+                    "$ref": "#/components/schemas/Pet"
+                },
+                "type": "array"
+            },
+            "Pet": {
+                "properties": {
+                    "tag": {
+                        "type": "string"
+                    },
+                    "id": {
+                        "format": "int64",
+                        "type": "integer"
+                    },
+                    "name": {
+                        "type": "string"
+                    }
+                },
+                "required": [
+                    "id",
+                    "name"
+                ]
+            }
+        }
+    }
+}'''
 
 
 @pytest.fixture
 def minimal_petstore_schema():
-    return '''openapi: 3.0.0
-info:
-  title: Swagger Petstore
-  description: ''
-  version: ''
-servers:
-  - url: http://petstore.swagger.io/v1
-paths:
-  /pets:
-    get:
-      tags:
-        - pets
-      summary: List all pets
-      operationId: listPets
-      parameters:
-        - name: limit
-          in: query
-          description: How many items to return at one time (max 100)
-          schema:
-            type: integer
-            format: int32
-    post:
-      tags:
-        - pets
-      summary: Create a pet
-      operationId: createPets
-  /pets/{petId}:
-    get:
-      tags:
-        - pets
-      summary: Info for a specific pet
-      operationId: showPetById
-      parameters:
-        - name: petId
-          in: path
-          description: The id of the pet to retrieve
-          required: true
-          schema:
-            type: string
-'''
+    return '''{
+    "openapi": "3.0.0",
+    "info": {
+        "title": "Swagger Petstore",
+        "description": "",
+        "version": ""
+    },
+    "servers": [
+        {
+            "url": "http://petstore.swagger.io/v1"
+        }
+    ],
+    "paths": {
+        "/pets": {
+            "get": {
+                "tags": [
+                    "pets"
+                ],
+                "summary": "List all pets",
+                "operationId": "listPets",
+                "parameters": [
+                    {
+                        "name": "limit",
+                        "in": "query",
+                        "description": "How many items to return at one time (max 100)",
+                        "schema": {
+                            "type": "integer",
+                            "format": "int32"
+                        }
+                    }
+                ]
+            },
+            "post": {
+                "tags": [
+                    "pets"
+                ],
+                "summary": "Create a pet",
+                "operationId": "createPets"
+            }
+        },
+        "/pets/{petId}": {
+            "get": {
+                "tags": [
+                    "pets"
+                ],
+                "summary": "Info for a specific pet",
+                "operationId": "showPetById",
+                "parameters": [
+                    {
+                        "name": "petId",
+                        "in": "path",
+                        "description": "The id of the pet to retrieve",
+                        "required": true,
+                        "schema": {
+                            "type": "string"
+                        }
+                    }
+                ]
+            }
+        }
+    }
+}'''
 
 
 def test_decode_openapi(openapi_codec, petstore_schema):

From 235f50e3fb89d2adedf96331b03bd0b6c0935cb5 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Thu, 15 Feb 2018 16:04:37 +0000
Subject: [PATCH 22/60] Schemas in tests should be bytestrings

---
 tests/codecs/test_openapi.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/codecs/test_openapi.py b/tests/codecs/test_openapi.py
index 5ee1a93..4a44e9c 100644
--- a/tests/codecs/test_openapi.py
+++ b/tests/codecs/test_openapi.py
@@ -11,7 +11,7 @@ def openapi_codec():
 
 @pytest.fixture
 def petstore_schema():
-    return '''{
+    return b'''{
     "openapi": "3.0.0",
     "info": {
         "title": "Swagger Petstore",
@@ -190,7 +190,7 @@ def petstore_schema():
 
 @pytest.fixture
 def minimal_petstore_schema():
-    return '''{
+    return b'''{
     "openapi": "3.0.0",
     "info": {
         "title": "Swagger Petstore",

From dc4edeae64c355a21508285b79e40a0b21029810 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Thu, 15 Feb 2018 16:26:30 +0000
Subject: [PATCH 23/60] Ensure OpenAPI.encode returns bytestrings

---
 coreapi/codecs/openapi.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
index c4714b3..097fc7d 100644
--- a/coreapi/codecs/openapi.py
+++ b/coreapi/codecs/openapi.py
@@ -1,5 +1,5 @@
 from coreapi.codecs import BaseCodec, JSONSchemaCodec
-from coreapi.compat import VERBOSE_SEPARATORS, dict_type, urlparse
+from coreapi.compat import VERBOSE_SEPARATORS, dict_type, force_bytes, urlparse
 from coreapi.document import Document, Link, Field
 from coreapi.exceptions import ParseError
 from coreapi.schemas import OpenAPI
@@ -203,8 +203,7 @@ def encode(self, document, **options):
             'indent': 4,
             'separators': VERBOSE_SEPARATORS
         }
-
-        return json.dumps(openapi, **kwargs)
+        return force_bytes(json.dumps(openapi, **kwargs))
 
     def get_paths(self, document):
         paths = dict_type()

From c85818c695cb6249c6f97fe5a0317e21107af8f7 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Thu, 15 Feb 2018 16:57:14 +0000
Subject: [PATCH 24/60] dict is ordered in Python 3.6

---
 coreapi/compat.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/coreapi/compat.py b/coreapi/compat.py
index d4fd043..0d3c46f 100644
--- a/coreapi/compat.py
+++ b/coreapi/compat.py
@@ -84,7 +84,7 @@ def force_text(string):
     return string
 
 
-if sys.version_info < (3, 5):
+if sys.version_info < (3, 6):
     dict_type = collections.OrderedDict
 else:
     dict_type = dict

From 566abbe73915b7250456539a029f031804d22d10 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Thu, 15 Feb 2018 17:25:20 +0000
Subject: [PATCH 25/60] Force ordering of document using in test case

---
 tests/codecs/test_openapi.py | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/tests/codecs/test_openapi.py b/tests/codecs/test_openapi.py
index 4a44e9c..081d80b 100644
--- a/tests/codecs/test_openapi.py
+++ b/tests/codecs/test_openapi.py
@@ -1,5 +1,6 @@
 from coreapi import typesys
 from coreapi.codecs import OpenAPICodec
+from coreapi.compat import dict_type
 from coreapi.document import Document, Link, Field
 import pytest
 
@@ -260,8 +261,8 @@ def test_decode_openapi(openapi_codec, petstore_schema):
         title='Swagger Petstore',
         url='http://petstore.swagger.io/v1',
         content={
-            'pets': {
-                'listPets': Link(
+            'pets': dict_type([
+                ('listPets', Link(
                     action='get',
                     url='http://petstore.swagger.io/pets',
                     title='List all pets',
@@ -274,13 +275,13 @@ def test_decode_openapi(openapi_codec, petstore_schema):
                             schema=typesys.integer(format='int32')
                         )
                     ]
-                ),
-                'createPets': Link(
+                )),
+                ('createPets', Link(
                     action='post',
                     url='http://petstore.swagger.io/pets',
                     title='Create a pet'
-                ),
-                'showPetById': Link(
+                )),
+                ('showPetById', Link(
                     action='get',
                     url='http://petstore.swagger.io/pets/{petId}',
                     title='Info for a specific pet',
@@ -293,8 +294,8 @@ def test_decode_openapi(openapi_codec, petstore_schema):
                             schema=typesys.string()
                         )
                     ]
-                )
-            }
+                ))
+            ])
         }
     )
     assert doc == expected

From 6530dc2b06eeffe3b7455f631aed624bf4e3ceb5 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 20 Feb 2018 10:22:49 +0000
Subject: [PATCH 26/60] Enforced ordering in Object

---
 coreapi/typesys.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index d1d139a..721f9d7 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -201,7 +201,7 @@ def __init__(self, value):
         super(Object, self).__init__()
 
         try:
-            value = dict(value)
+            value = dict_type(value)
         except TypeError:
             self.error('type')
 

From 09518cd567b142e9bb20bedd547f5b34ab3fa3df Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 20 Feb 2018 10:23:17 +0000
Subject: [PATCH 27/60] Drop commented-out YAML code

---
 coreapi/codecs/openapi.py | 62 ---------------------------------------
 1 file changed, 62 deletions(-)

diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
index 097fc7d..9aaa551 100644
--- a/coreapi/codecs/openapi.py
+++ b/coreapi/codecs/openapi.py
@@ -11,68 +11,6 @@
 ]
 
 
-# def represent_odict(dump, tag, mapping, flow_style=None):
-#     """Like BaseRepresenter.represent_mapping, but does not issue the sort().
-#     """
-#     value = []
-#     node = yaml.MappingNode(tag, value, flow_style=flow_style)
-#     if dump.alias_key is not None:
-#         dump.represented_objects[dump.alias_key] = node
-#     best_style = True
-#     if hasattr(mapping, 'items'):
-#         mapping = mapping.items()
-#     for item_key, item_value in mapping:
-#         node_key = dump.represent_data(item_key)
-#         node_value = dump.represent_data(item_value)
-#         if not (isinstance(node_key, yaml.ScalarNode) and not node_key.style):
-#             best_style = False
-#         if not (isinstance(node_value, yaml.ScalarNode) and not node_value.style):
-#             best_style = False
-#         value.append((node_key, node_value))
-#     if flow_style is None:
-#         if dump.default_flow_style is not None:
-#             node.flow_style = dump.default_flow_style
-#         else:
-#             node.flow_style = best_style
-#     return node
-#
-#
-# def represent_list(dump, tag, sequence, flow_style=None):
-#     value = []
-#     node = yaml.SequenceNode(tag, value, flow_style=flow_style)
-#     if dump.alias_key is not None:
-#         dump.represented_objects[dump.alias_key] = node
-#     best_style = True
-#     for item in sequence:
-#         node_item = dump.represent_data(item)
-#         if not (isinstance(node_item, yaml.ScalarNode) and not node_item.style):
-#             best_style = False
-#         value.append(node_item)
-#     if flow_style is None:
-#         if dump.default_flow_style is not None:
-#             node.flow_style = dump.default_flow_style
-#         else:
-#             node.flow_style = best_style
-#     return node
-#
-#
-# class CustomSafeDumper(yaml.SafeDumper):
-#     def increase_indent(self, flow=False, indentless=False):
-#         return super(CustomSafeDumper, self).increase_indent(flow, False)
-#
-#
-# CustomSafeDumper.add_multi_representer(
-#     dict_type,
-#     lambda dumper, value: represent_odict(dumper, u'tag:yaml.org,2002:map', value)
-# )
-# CustomSafeDumper.add_multi_representer(
-#     list,
-#     lambda dumper, value: represent_list(dumper, u'tag:yaml.org,2002:seq', value)
-# )
-#
-# return yaml.dump(openapi, Dumper=CustomSafeDumper, default_flow_style=False)
-
-
 def _relative_url(base_url, url):
     """
     Return a graceful link for a URL relative to a base URL.

From 73c50154615b64ea9f8cc5d446165ad83039ea07 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 20 Feb 2018 11:33:41 +0000
Subject: [PATCH 28/60] Drop itypes from transports/codecs/client

---
 coreapi/client.py          | 7 +++----
 coreapi/codecs/base.py     | 5 +----
 coreapi/transports/base.py | 3 +--
 coreapi/transports/http.py | 3 +--
 4 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/coreapi/client.py b/coreapi/client.py
index ece3d27..027bf33 100644
--- a/coreapi/client.py
+++ b/coreapi/client.py
@@ -2,7 +2,6 @@
 from coreapi.compat import string_types
 from coreapi.document import Link
 from coreapi.utils import determine_transport, get_installed_codecs
-import itypes
 
 
 def _lookup_link(document, keys):
@@ -87,7 +86,7 @@ def get_default_transports(auth=None, session=None):
     ]
 
 
-class Client(itypes.Object):
+class Client(object):
     def __init__(self, decoders=None, transports=None, auth=None, session=None):
         assert transports is None or auth is None, (
             "Cannot specify both 'auth' and 'transports'. "
@@ -98,8 +97,8 @@ def __init__(self, decoders=None, transports=None, auth=None, session=None):
             decoders = get_default_decoders()
         if transports is None:
             transports = get_default_transports(auth=auth, session=session)
-        self._decoders = itypes.List(decoders)
-        self._transports = itypes.List(transports)
+        self._decoders = list(decoders)
+        self._transports = list(transports)
 
     @property
     def decoders(self):
diff --git a/coreapi/codecs/base.py b/coreapi/codecs/base.py
index 6f20044..dda33be 100644
--- a/coreapi/codecs/base.py
+++ b/coreapi/codecs/base.py
@@ -1,7 +1,4 @@
-import itypes
-
-
-class BaseCodec(itypes.Object):
+class BaseCodec(object):
     media_type = None
 
     # We don't implement stubs, to ensure that we can check which of these
diff --git a/coreapi/transports/base.py b/coreapi/transports/base.py
index b19f0cc..baef9f8 100644
--- a/coreapi/transports/base.py
+++ b/coreapi/transports/base.py
@@ -1,8 +1,7 @@
 # coding: utf-8
-import itypes
 
 
-class BaseTransport(itypes.Object):
+class BaseTransport(object):
     schemes = None
 
     def transition(self, link, decoders, params=None, link_ancestors=None, force_codec=False):
diff --git a/coreapi/transports/http.py b/coreapi/transports/http.py
index e6f5256..cbe368e 100644
--- a/coreapi/transports/http.py
+++ b/coreapi/transports/http.py
@@ -8,7 +8,6 @@
 from coreapi.utils import guess_filename, is_file, File
 import collections
 import requests
-import itypes
 import mimetypes
 import uritemplate
 
@@ -271,7 +270,7 @@ def __init__(self, headers=None, auth=None, session=None):
         if not getattr(session.auth, 'allow_cookies', False):
             session.cookies.set_policy(BlockAll())
 
-        self._headers = itypes.Dict(headers or {})
+        self._headers = {} if (headers is None) else dict(headers)
         self._session = session
 
     @property

From 2d6e0bcff7b9fb651e521a7e1987d4074c84ea52 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 20 Feb 2018 11:37:24 +0000
Subject: [PATCH 29/60] Drop BaseCodec dump/load/supports

---
 coreapi/codecs/base.py     | 22 ----------------------
 coreapi/transports/http.py |  2 +-
 2 files changed, 1 insertion(+), 23 deletions(-)

diff --git a/coreapi/codecs/base.py b/coreapi/codecs/base.py
index dda33be..d041cb3 100644
--- a/coreapi/codecs/base.py
+++ b/coreapi/codecs/base.py
@@ -11,28 +11,6 @@ class BaseCodec(object):
     # def encode(self, document, **options):
     #    pass
 
-    # The following will be removed at some point, most likely in a 2.1 release:
-    def dump(self, *args, **kwargs):
-        # Fallback for v1.x interface
-        return self.encode(*args, **kwargs)
-
-    def load(self, *args, **kwargs):
-        # Fallback for v1.x interface
-        return self.decode(*args, **kwargs)
-
-    @property
-    def supports(self):
-        # Fallback for v1.x interface.
-        if '+' not in self.media_type:
-            return ['data']
-
-        ret = []
-        if hasattr(self, 'encode'):
-            ret.append('encoding')
-        if hasattr(self, 'decode'):
-            ret.append('decoding')
-        return ret
-
     def get_media_types(self):
         # Fallback, while transitioning from `application/vnd.coreapi+json`
         # to simply `application/coreapi+json`.
diff --git a/coreapi/transports/http.py b/coreapi/transports/http.py
index cbe368e..4e0ccc0 100644
--- a/coreapi/transports/http.py
+++ b/coreapi/transports/http.py
@@ -243,7 +243,7 @@ def _decode_result(response, decoders, force_codec=False):
         if 'content-disposition' in response.headers:
             options['content_disposition'] = response.headers['content-disposition']
 
-        result = codec.load(response.content, **options)
+        result = codec.decode(response.content, **options)
     else:
         # No content returned in response.
         result = None

From 48784f47990d63c75de28387e7b310e3d69b8a7e Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 20 Feb 2018 13:35:23 +0000
Subject: [PATCH 30/60] Add document.version

---
 coreapi/codecs/openapi.py | 5 +++--
 coreapi/document.py       | 9 ++++++++-
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
index 9aaa551..044ae78 100644
--- a/coreapi/codecs/openapi.py
+++ b/coreapi/codecs/openapi.py
@@ -38,9 +38,10 @@ def decode(self, bytestring, **options):
         openapi = OpenAPI(data)
         title = openapi.lookup(['info', 'title'])
         description = openapi.lookup(['info', 'description'])
+        version = openapi.lookup(['info', 'version'])
         base_url = openapi.lookup(['servers', 0, 'url'])
         content = self.get_links(openapi, base_url)
-        return Document(title=title, description=description, url=base_url, content=content)
+        return Document(title=title, description=description, version=version, url=base_url, content=content)
 
     def get_links(self, openapi, base_url):
         """
@@ -126,7 +127,7 @@ def encode(self, document, **options):
         openapi = OpenAPI({
             'openapi': '3.0.0',
             'info': {
-                'version': '',
+                'version': document.version,
                 'title': document.title,
                 'description': document.description
             },
diff --git a/coreapi/document.py b/coreapi/document.py
index 70102fc..f6467a2 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -49,7 +49,7 @@ class Document(itypes.Dict):
     Expresses the data that the client may access,
     and the actions that the client may perform.
     """
-    def __init__(self, url=None, title=None, description=None, media_type=None, content=None):
+    def __init__(self, url=None, title=None, description=None, version=None, media_type=None, content=None):
         content = {} if (content is None) else content
 
         if url is not None and not isinstance(url, string_types):
@@ -58,6 +58,8 @@ def __init__(self, url=None, title=None, description=None, media_type=None, cont
             raise TypeError("'title' must be a string.")
         if description is not None and not isinstance(description, string_types):
             raise TypeError("'description' must be a string.")
+        if version is not None and not isinstance(version, string_types):
+            raise TypeError("'version' must be a string.")
         if media_type is not None and not isinstance(media_type, string_types):
             raise TypeError("'media_type' must be a string.")
         if not isinstance(content, dict):
@@ -68,6 +70,7 @@ def __init__(self, url=None, title=None, description=None, media_type=None, cont
         self._url = '' if (url is None) else url
         self._title = '' if (title is None) else title
         self._description = '' if (description is None) else description
+        self._version = '' if (version is None) else version
         self._media_type = '' if (media_type is None) else media_type
         self._data = {key: _to_immutable(value) for key, value in content.items()}
 
@@ -102,6 +105,10 @@ def title(self):
     def description(self):
         return self._description
 
+    @property
+    def version(self):
+        return self._version
+
     @property
     def media_type(self):
         return self._media_type

From 5e19106fd085cb5bc961af0467fcb3ce7e98f85f Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 20 Feb 2018 13:47:42 +0000
Subject: [PATCH 31/60] Drop itypes from Error

---
 coreapi/document.py    | 10 ++++++++--
 tests/test_document.py |  8 --------
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/coreapi/document.py b/coreapi/document.py
index f6467a2..c07610e 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -1,6 +1,6 @@
 # coding: utf-8
 from __future__ import unicode_literals
-from collections import OrderedDict
+from collections import Mapping, OrderedDict
 from coreapi.compat import coreschema_to_typesys, string_types
 import itypes
 
@@ -258,7 +258,7 @@ def __eq__(self, other):
         )
 
 
-class Error(itypes.Dict):
+class Error(Mapping):
     def __init__(self, title=None, content=None):
         data = {} if (content is None) else content
 
@@ -276,6 +276,12 @@ def __iter__(self):
         items = sorted(self._data.items(), key=_key_sorting)
         return iter([key for key, value in items])
 
+    def __len__(self):
+        return len(self._data)
+
+    def __getitem__(self, key):
+        return self._data[key]
+
     def __repr__(self):
         return _repr(self)
 
diff --git a/tests/test_document.py b/tests/test_document.py
index 6b10f97..1da002e 100644
--- a/tests/test_document.py
+++ b/tests/test_document.py
@@ -97,14 +97,6 @@ def test_link_does_not_support_property_assignment():
         link.integer = 456
 
 
-# Errors are immutable.
-
-def test_error_does_not_support_property_assignment():
-    error = Error(content={'messages': ['failed']})
-    with pytest.raises(TypeError):
-        error.integer = 456
-
-
 # Children in documents are immutable primitives.
 
 def test_document_dictionaries_coerced_to_objects(doc):

From d1c006f02803f7db33ab154fd3d3cbc39ce2ae7c Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 20 Feb 2018 13:48:44 +0000
Subject: [PATCH 32/60] Drop itypes from Link

---
 coreapi/document.py    | 2 +-
 tests/test_document.py | 8 --------
 2 files changed, 1 insertion(+), 9 deletions(-)

diff --git a/coreapi/document.py b/coreapi/document.py
index c07610e..e6a59da 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -163,7 +163,7 @@ def links(self):
         ])
 
 
-class Link(itypes.Object):
+class Link(object):
     """
     Links represent the actions that a client may perform.
     """
diff --git a/tests/test_document.py b/tests/test_document.py
index 1da002e..5decd84 100644
--- a/tests/test_document.py
+++ b/tests/test_document.py
@@ -89,14 +89,6 @@ def test_object_does_not_support_key_deletion(obj):
         del obj['key']
 
 
-# Links are immutable.
-
-def test_link_does_not_support_property_assignment():
-    link = Link()
-    with pytest.raises(TypeError):
-        link.integer = 456
-
-
 # Children in documents are immutable primitives.
 
 def test_document_dictionaries_coerced_to_objects(doc):

From b52553e0ed47eabdd4a6a9948be097d2467df0f3 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 20 Feb 2018 13:52:30 +0000
Subject: [PATCH 33/60] Drop itypes

---
 coreapi/document.py    | 17 ++++++++++++++---
 requirements.txt       |  1 -
 setup.py               |  1 -
 tests/test_document.py | 10 ----------
 4 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/coreapi/document.py b/coreapi/document.py
index e6a59da..ba54c07 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -2,7 +2,6 @@
 from __future__ import unicode_literals
 from collections import Mapping, OrderedDict
 from coreapi.compat import coreschema_to_typesys, string_types
-import itypes
 
 
 def _to_immutable(value):
@@ -42,7 +41,7 @@ def _key_sorting(item):
 
 # The Core API primitives:
 
-class Document(itypes.Dict):
+class Document(Mapping):
     """
     The Core API document type.
 
@@ -78,6 +77,12 @@ def __iter__(self):
         items = sorted(self._data.items(), key=_key_sorting)
         return iter([key for key, value in items])
 
+    def __len__(self):
+        return len(self._data)
+
+    def __getitem__(self, key):
+        return self._data[key]
+
     def __repr__(self):
         return _repr(self)
 
@@ -128,7 +133,7 @@ def links(self):
         ])
 
 
-class Object(itypes.Dict):
+class Object(Mapping):
     """
     An immutable mapping of strings to values.
     """
@@ -142,6 +147,12 @@ def __iter__(self):
         items = sorted(self._data.items(), key=_key_sorting)
         return iter([key for key, value in items])
 
+    def __len__(self):
+        return len(self._data)
+
+    def __getitem__(self, key):
+        return self._data[key]
+
     def __repr__(self):
         return _repr(self)
 
diff --git a/requirements.txt b/requirements.txt
index 4a7d2a8..401ec84 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,4 @@
 # Package requirements
-itypes
 requests
 uritemplate
 
diff --git a/setup.py b/setup.py
index 2fa32a5..dcfde78 100755
--- a/setup.py
+++ b/setup.py
@@ -64,7 +64,6 @@ def get_package_data(package):
     package_data=get_package_data('coreapi'),
     install_requires=[
         'requests',
-        'itypes',
         'uritemplate'
     ],
     entry_points={
diff --git a/tests/test_document.py b/tests/test_document.py
index 5decd84..b9c7743 100644
--- a/tests/test_document.py
+++ b/tests/test_document.py
@@ -62,11 +62,6 @@ def test_document_does_not_support_key_assignment(doc):
         doc['integer'] = 456
 
 
-def test_document_does_not_support_property_assignment(doc):
-    with pytest.raises(TypeError):
-        doc.integer = 456
-
-
 def test_document_does_not_support_key_deletion(doc):
     with pytest.raises(TypeError):
         del doc['integer']
@@ -79,11 +74,6 @@ def test_object_does_not_support_key_assignment(obj):
         obj['key'] = 456
 
 
-def test_object_does_not_support_property_assignment(obj):
-    with pytest.raises(TypeError):
-        obj.integer = 456
-
-
 def test_object_does_not_support_key_deletion(obj):
     with pytest.raises(TypeError):
         del obj['key']

From b1e34183cd0167292278b0d6a7e5e7922d9e58d4 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 20 Feb 2018 15:12:07 +0000
Subject: [PATCH 34/60] Drop client.reload

---
 coreapi/client.py | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/coreapi/client.py b/coreapi/client.py
index 027bf33..0432c2d 100644
--- a/coreapi/client.py
+++ b/coreapi/client.py
@@ -126,10 +126,6 @@ def get(self, url, format=None, force_codec=False):
         transport = determine_transport(self.transports, link.url)
         return transport.transition(link, decoders, force_codec=force_codec)
 
-    def reload(self, document, format=None, force_codec=False):
-        # Fallback for v1.x. To be removed in favour of explict `get` style.
-        return self.get(document.url, format=format, force_codec=force_codec)
-
     def action(self, document, keys, params=None, validate=True, overrides=None):
         if isinstance(keys, string_types):
             keys = [keys]

From 7b0cf7d28218153c4ed6099843b269c0a3ddc868 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 20 Feb 2018 15:12:36 +0000
Subject: [PATCH 35/60] _to_immutable -> _to_objects

---
 coreapi/document.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/coreapi/document.py b/coreapi/document.py
index ba54c07..f5e792a 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -4,7 +4,7 @@
 from coreapi.compat import coreschema_to_typesys, string_types
 
 
-def _to_immutable(value):
+def _to_objects(value):
     if isinstance(value, dict):
         return Object(value)
     return value
@@ -71,7 +71,7 @@ def __init__(self, url=None, title=None, description=None, version=None, media_t
         self._description = '' if (description is None) else description
         self._version = '' if (version is None) else version
         self._media_type = '' if (media_type is None) else media_type
-        self._data = {key: _to_immutable(value) for key, value in content.items()}
+        self._data = {key: _to_objects(value) for key, value in content.items()}
 
     def __iter__(self):
         items = sorted(self._data.items(), key=_key_sorting)
@@ -141,7 +141,7 @@ def __init__(self, *args, **kwargs):
         data = dict(*args, **kwargs)
         if any([not isinstance(key, string_types) for key in data.keys()]):
             raise TypeError('Object keys must be strings.')
-        self._data = {key: _to_immutable(value) for key, value in data.items()}
+        self._data = {key: _to_objects(value) for key, value in data.items()}
 
     def __iter__(self):
         items = sorted(self._data.items(), key=_key_sorting)
@@ -281,7 +281,7 @@ def __init__(self, title=None, content=None):
             raise TypeError('content keys must be strings.')
 
         self._title = '' if (title is None) else title
-        self._data = {key: _to_immutable(value) for key, value in data.items()}
+        self._data = {key: _to_objects(value) for key, value in data.items()}
 
     def __iter__(self):
         items = sorted(self._data.items(), key=_key_sorting)

From e663b9f1236fd58895b8a9e8b334a17f3ebc675f Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 20 Feb 2018 15:18:11 +0000
Subject: [PATCH 36/60] Drop reload from tests

---
 tests/test_integration.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/test_integration.py b/tests/test_integration.py
index 0a2e602..44b0f43 100644
--- a/tests/test_integration.py
+++ b/tests/test_integration.py
@@ -70,7 +70,7 @@ def mockreturn(self, request, *args, **kwargs):
 
     client = coreapi.Client()
     doc = coreapi.Document(url='http://example.org')
-    doc = client.reload(doc)
+    doc = client.get(doc.url)
     assert doc == {'example': 123}
 
 

From f09ca743cfa3a15e8b309e3812e1184c202579de Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 20 Feb 2018 15:27:43 +0000
Subject: [PATCH 37/60] 'enum' defined on types

---
 coreapi/codecs/corejson.py    |  6 +++--
 coreapi/schemas/jsonschema.py |  1 +
 coreapi/schemas/openapi.py    |  4 ++--
 coreapi/typesys.py            | 42 +++++++++++++----------------------
 tests/test_codecs.py          |  6 ++---
 5 files changed, 26 insertions(+), 33 deletions(-)

diff --git a/coreapi/codecs/corejson.py b/coreapi/codecs/corejson.py
index cd1f000..b21c183 100644
--- a/coreapi/codecs/corejson.py
+++ b/coreapi/codecs/corejson.py
@@ -19,7 +19,6 @@
     typesys.Integer: 'integer',
     typesys.String: 'string',
     typesys.Boolean: 'boolean',
-    typesys.Enum: 'enum',
     typesys.Any: 'anything'
 }
 
@@ -42,7 +41,7 @@ def encode_schema_to_corejson(schema):
         'title': schema.title or '',
         'description': schema.description or ''
     }
-    if hasattr(schema, 'enum'):
+    if getattr(schema, 'enum', None) is not None:
         retval['enum'] = schema.enum
     return retval
 
@@ -54,7 +53,10 @@ def decode_schema_from_corejson(data):
 
     kwargs = {'title': title, 'description': description}
     if type_id == 'enum':
+        type_id = 'string'
         kwargs['enum'] = _get_list(data, 'enum')
+    elif 'enum' in data:
+        kwargs['enum'] = data['enum']
 
     schema_cls = TYPE_ID_TO_SCHEMA_CLASS.get(type_id, typesys.Any)
     return type(schema_cls.__name__, (schema_cls,), kwargs)
diff --git a/coreapi/schemas/jsonschema.py b/coreapi/schemas/jsonschema.py
index 1dacfc9..959eccf 100644
--- a/coreapi/schemas/jsonschema.py
+++ b/coreapi/schemas/jsonschema.py
@@ -6,6 +6,7 @@ class JSONSchema(typesys.Object):
     properties = dict_type([
         ('$ref', typesys.string()),
         ('type', typesys.string()),
+        ('enum', typesys.Any),
 
         # String
         ('minLength', typesys.integer(minimum=0, default=0)),
diff --git a/coreapi/schemas/openapi.py b/coreapi/schemas/openapi.py
index 3940434..3eb22ed 100644
--- a/coreapi/schemas/openapi.py
+++ b/coreapi/schemas/openapi.py
@@ -64,7 +64,7 @@ class SecurityRequirement(typesys.Object):
 class Parameter(typesys.Object):
     properties = dict_type([
         ('name', typesys.string()),
-        ('in', typesys.enum(enum=['query', 'header', 'path', 'cookie'])),
+        ('in', typesys.string(enum=['query', 'header', 'path', 'cookie'])),
         ('description', typesys.string(format='textarea')),
         ('required', typesys.boolean()),
         ('deprecated', typesys.boolean()),
@@ -83,7 +83,7 @@ class Operation(typesys.Object):
         ('description', typesys.string(format='textarea')),
         ('externalDocs', ExternalDocs),
         ('operationId', typesys.string()),
-        ('parameters', typesys.array(items=Parameter)),  # Parameter | ReferenceObject
+        ('parameters', typesys.array(items=Parameter)),  # TODO: Parameter | ReferenceObject
         # TODO: 'requestBody'
         # TODO: 'responses'
         # TODO: 'callbacks'
diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index 721f9d7..6958816 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -29,6 +29,8 @@ class String(str):
         'min_length': 'Must have at least {min_length} characters.',
         'pattern': 'Must match the pattern /{pattern}/.',
         'format': 'Must be a valid {format}.',
+        'enum': 'Must be a valid choice.',
+        'exact': 'Must be {exact}.'
     }
     title = None  # type: str
     description = None  # type: str
@@ -36,6 +38,7 @@ class String(str):
     min_length = None  # type: int
     pattern = None  # type: str
     format = None  # type: Any
+    enum = None  # type: List[str]
     trim_whitespace = True
 
     def __new__(cls, value):
@@ -44,6 +47,12 @@ def __new__(cls, value):
         if cls.trim_whitespace:
             value = value.strip()
 
+        if cls.enum is not None:
+            if value not in cls.enum:
+                if len(cls.enum) == 1:
+                    cls.error('exact')
+                cls.error('enum')
+
         if cls.min_length is not None:
             if len(value) < cls.min_length:
                 if cls.min_length == 1:
@@ -82,6 +91,7 @@ class NumericType(object):
     }
     title = None  # type: str
     description = None  # type: str
+    enum = None  # type: List[Union[float, int]]
     minimum = None  # type: Union[float, int]
     maximum = None  # type: Union[float, int]
     exclusive_minimum = False
@@ -95,6 +105,12 @@ def __new__(cls, value):
         except (TypeError, ValueError):
             cls.error('type')
 
+        if cls.enum is not None:
+            if value not in cls.enum:
+                if len(cls.enum) == 1:
+                    cls.error('exact')
+                cls.error('enum')
+
         if cls.minimum is not None:
             if cls.exclusive_minimum:
                 if value <= cls.minimum:
@@ -162,28 +178,6 @@ def error(cls, code):
         raise ValidationError(message)  # from None
 
 
-class Enum(str):
-    errors = {
-        'enum': 'Must be a valid choice.',
-        'exact': 'Must be {exact}.'
-    }
-    title = None  # type: str
-    description = None  # type: str
-    enum = []  # type: List[str]
-
-    def __new__(cls, value):
-        if value not in cls.enum:
-            if len(cls.enum) == 1:
-                cls.error('exact')
-            cls.error('enum')
-        return value
-
-    @classmethod
-    def error(cls, code):
-        message = cls.errors[code].format(**cls.__dict__)
-        raise ValidationError(message)  # from None
-
-
 class Object(dict_type):
     errors = {
         'type': 'Must be an object.',
@@ -369,10 +363,6 @@ def boolean(**kwargs):
     return type('Boolean', (Boolean,), kwargs)
 
 
-def enum(**kwargs):
-    return type('Enum', (Enum,), kwargs)
-
-
 def array(**kwargs):
     return type('Array', (Array,), kwargs)
 
diff --git a/tests/test_codecs.py b/tests/test_codecs.py
index 170ef69..5d2f72d 100644
--- a/tests/test_codecs.py
+++ b/tests/test_codecs.py
@@ -27,7 +27,7 @@ def doc():
                 fields=[
                     Field(name='noschema'),
                     Field(name='string_example', schema=typesys.string()),
-                    Field(name='enum_example', schema=typesys.enum(enum=['a', 'b', 'c'])),
+                    Field(name='enum_example', schema=typesys.string(enum=['a', 'b', 'c'])),
                 ]),
             'nested': {'child': Link(url='http://example.org/123')},
             '_type': 'needs escaping'
@@ -60,7 +60,7 @@ def test_document_to_primitive(doc):
             {
                 'name': 'enum_example',
                 'schema': {
-                    '_type': 'enum',
+                    '_type': 'string',
                     'title': '',
                     'description': '',
                     'enum': ['a', 'b', 'c'],
@@ -98,7 +98,7 @@ def test_primitive_to_document(doc):
                 {
                     'name': 'enum_example',
                     'schema': {
-                        '_type': 'enum',
+                        '_type': 'string',
                         'title': '',
                         'description': '',
                         'enum': ['a', 'b', 'c'],

From 93482e9eb08d3d8ced7302fa752f24870ff0ddd0 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 20 Feb 2018 16:27:06 +0000
Subject: [PATCH 38/60] Add openapi codec to setup

---
 setup.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/setup.py b/setup.py
index dcfde78..575653a 100755
--- a/setup.py
+++ b/setup.py
@@ -69,6 +69,7 @@ def get_package_data(package):
     entry_points={
         'coreapi.codecs': [
             'corejson=coreapi.codecs:CoreJSONCodec',
+            'openapi=coreapi.codecs:OpenAPICodec',
             'json=coreapi.codecs:JSONCodec',
             'text=coreapi.codecs:TextCodec',
             'download=coreapi.codecs:DownloadCodec',

From 54199e3ee80145e6be2e305f91754e1d33655178 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 20 Feb 2018 16:27:26 +0000
Subject: [PATCH 39/60] Add Field.title

---
 coreapi/document.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/coreapi/document.py b/coreapi/document.py
index f5e792a..89852c6 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -249,12 +249,13 @@ def __str__(self):
 
 
 class Field(object):
-    def __init__(self, name, required=False, location='', schema=None, description=None, example=None):
+    def __init__(self, name, title='', description='', required=False, location='', schema=None, example=None):
         self.name = name
-        self.required = required
+        self.title = title
+        self.description = description
         self.location = location
+        self.required = required
         self.schema = coreschema_to_typesys(schema)
-        self.description = description
         self.example = example
 
     def __eq__(self, other):

From 8c1748ea147c652f8bf47131524735034c10c3c2 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 20 Feb 2018 16:47:54 +0000
Subject: [PATCH 40/60] Use Link.method. Put .action towards deprecation.

---
 coreapi/client.py          |  7 ++++---
 coreapi/codecs/corejson.py |  2 +-
 coreapi/codecs/openapi.py  |  2 +-
 coreapi/codecs/python.py   |  4 ++--
 coreapi/document.py        | 30 +++++++++++++++++++-----------
 coreapi/transports/http.py |  8 ++++----
 tests/test_document.py     | 14 +++++++-------
 7 files changed, 38 insertions(+), 29 deletions(-)

diff --git a/coreapi/client.py b/coreapi/client.py
index 0432c2d..9a99c8f 100644
--- a/coreapi/client.py
+++ b/coreapi/client.py
@@ -109,7 +109,7 @@ def transports(self):
         return self._transports
 
     def get(self, url, format=None, force_codec=False):
-        link = Link(url, action='get')
+        link = Link(url, method='get')
 
         decoders = self.decoders
         if format:
@@ -141,10 +141,11 @@ def action(self, document, keys, params=None, validate=True, overrides=None):
         if overrides:
             # Handle any explicit overrides.
             url = overrides.get('url', link.url)
-            action = overrides.get('action', link.action)
+            method = overrides.get('method', link.method)
+            method = overrides.get('action', method)  # TODO: Deprecate
             encoding = overrides.get('encoding', link.encoding)
             fields = overrides.get('fields', link.fields)
-            link = Link(url, action=action, encoding=encoding, fields=fields)
+            link = Link(url, method=method, encoding=encoding, fields=fields)
 
         # Perform the action, and return a new document.
         transport = determine_transport(self.transports, link.url)
diff --git a/coreapi/codecs/corejson.py b/coreapi/codecs/corejson.py
index b21c183..dcf2874 100644
--- a/coreapi/codecs/corejson.py
+++ b/coreapi/codecs/corejson.py
@@ -275,7 +275,7 @@ def _primitive_to_document(data, base_url=None):
             for item in fields if isinstance(item, dict)
         ]
         return Link(
-            url=url, action=action, encoding=encoding,
+            url=url, method=action, encoding=encoding,
             title=title, description=description, fields=fields
         )
 
diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
index 044ae78..4bdd15f 100644
--- a/coreapi/codecs/openapi.py
+++ b/coreapi/codecs/openapi.py
@@ -93,7 +93,7 @@ def get_link(self, base_url, path, path_info, operation, operation_info):
 
         return Link(
             url=urlparse.urljoin(base_url, path),
-            action=operation,
+            method=operation,
             title=title,
             description=description,
             fields=fields
diff --git a/coreapi/codecs/python.py b/coreapi/codecs/python.py
index c1e34ac..0a1137a 100644
--- a/coreapi/codecs/python.py
+++ b/coreapi/codecs/python.py
@@ -33,8 +33,8 @@ def _to_repr(node):
 
     elif isinstance(node, Link):
         args = "url=%s" % repr(node.url)
-        if node.action:
-            args += ", action=%s" % repr(node.action)
+        if node.method:
+            args += ", method=%s" % repr(node.method)
         if node.encoding:
             args += ", encoding=%s" % repr(node.encoding)
         if node.description:
diff --git a/coreapi/document.py b/coreapi/document.py
index 89852c6..4dd537e 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -24,18 +24,18 @@ def _key_sorting(item):
     """
     Document and Object sorting.
     Regular attributes sorted alphabetically.
-    Links are sorted based on their URL and action.
+    Links are sorted based on their URL and method.
     """
     key, value = item
     if isinstance(value, Link):
-        action_priority = {
+        method_priority = {
             'get': 0,
             'post': 1,
             'put': 2,
             'patch': 3,
             'delete': 4
-        }.get(value.action, 5)
-        return (1, (value.url, action_priority))
+        }.get(value.method, 5)
+        return (1, (value.url, method_priority))
     return (0, key)
 
 
@@ -178,11 +178,14 @@ class Link(object):
     """
     Links represent the actions that a client may perform.
     """
-    def __init__(self, url=None, action=None, encoding=None, title=None, description=None, fields=None):
+    def __init__(self, url=None, method=None, encoding=None, title=None, description=None, fields=None, action=None):
+        if action is not None:
+            method = action  # Deprecated
+
         if (url is not None) and (not isinstance(url, string_types)):
             raise TypeError("Argument 'url' must be a string.")
-        if (action is not None) and (not isinstance(action, string_types)):
-            raise TypeError("Argument 'action' must be a string.")
+        if (method is not None) and (not isinstance(method, string_types)):
+            raise TypeError("Argument 'method' must be a string.")
         if (encoding is not None) and (not isinstance(encoding, string_types)):
             raise TypeError("Argument 'encoding' must be a string.")
         if (title is not None) and (not isinstance(title, string_types)):
@@ -198,7 +201,7 @@ def __init__(self, url=None, action=None, encoding=None, title=None, description
             raise TypeError("Argument 'fields' must be a list of strings or fields.")
 
         self._url = '' if (url is None) else url
-        self._action = '' if (action is None) else action
+        self._method = '' if (method is None) else method
         self._encoding = '' if (encoding is None) else encoding
         self._title = '' if (title is None) else title
         self._description = '' if (description is None) else description
@@ -212,8 +215,8 @@ def url(self):
         return self._url
 
     @property
-    def action(self):
-        return self._action
+    def method(self):
+        return self._method
 
     @property
     def encoding(self):
@@ -231,11 +234,16 @@ def description(self):
     def fields(self):
         return self._fields
 
+    @property
+    def action(self):
+        # Deprecated
+        return self._method
+
     def __eq__(self, other):
         return (
             isinstance(other, Link) and
             self.url == other.url and
-            self.action == other.action and
+            self.method == other.method and
             self.encoding == other.encoding and
             self.description == other.description and
             sorted(self.fields, key=lambda f: f.name) == sorted(other.fields, key=lambda f: f.name)
diff --git a/coreapi/transports/http.py b/coreapi/transports/http.py
index 4e0ccc0..5d6b830 100644
--- a/coreapi/transports/http.py
+++ b/coreapi/transports/http.py
@@ -39,10 +39,10 @@ class BlockAll(cookiejar.CookiePolicy):
     rfc2965 = hide_cookie2 = False
 
 
-def _get_method(action):
-    if not action:
+def _get_method(method):
+    if not method:
         return 'GET'
-    return action.upper()
+    return method.upper()
 
 
 def _get_encoding(encoding):
@@ -279,7 +279,7 @@ def headers(self):
 
     def transition(self, link, decoders, params=None, force_codec=False):
         session = self._session
-        method = _get_method(link.action)
+        method = _get_method(link.method)
         encoding = _get_encoding(link.encoding)
         params = _get_params(method, encoding, link.fields, params)
         url = _get_url(link.url, params.path)
diff --git a/tests/test_document.py b/tests/test_document.py
index b9c7743..aced4d6 100644
--- a/tests/test_document.py
+++ b/tests/test_document.py
@@ -15,7 +15,7 @@ def doc():
             'dict': {'key': 'value'},
             'link': Link(
                 url='/',
-                action='post',
+                method='post',
                 fields=['optional', Field('required', required=True, location='path')]
             ),
             'nested': {'child': Link(url='/123')}
@@ -31,7 +31,7 @@ def obj():
 def link():
     return Link(
         url='/',
-        action='post',
+        method='post',
         fields=[Field('required', required=True), 'optional']
     )
 
@@ -93,7 +93,7 @@ def test_document_repr(doc):
         "'dict': {'key': 'value'}, "
         "'integer': 123, "
         "'nested': {'child': Link(url='/123')}, "
-        "'link': Link(url='/', action='post', "
+        "'link': Link(url='/', method='post', "
         "fields=['optional', Field('required', required=True, location='path')])"
         "})"
     )
@@ -106,7 +106,7 @@ def test_object_repr(obj):
 
 
 def test_link_repr(link):
-    assert repr(link) == "Link(url='/', action='post', fields=[Field('required', required=True), 'optional'])"
+    assert repr(link) == "Link(url='/', method='post', fields=[Field('required', required=True), 'optional'])"
     assert eval(repr(link)) == link
 
 
@@ -184,7 +184,7 @@ def test_document_equality(doc):
         'dict': {'key': 'value'},
         'link': Link(
             url='/',
-            action='post',
+            method='post',
             fields=['optional', Field('required', required=True, location='path')]
         ),
         'nested': {'child': Link(url='/123')}
@@ -254,9 +254,9 @@ def test_link_url_must_be_string():
         Link(url=123)
 
 
-def test_link_action_must_be_string():
+def test_link_mthod_must_be_string():
     with pytest.raises(TypeError):
-        Link(action=123)
+        Link(method=123)
 
 
 def test_link_fields_must_be_list():

From ae79ef584f39f714a92cd0ca360afe2cce7c9215 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 21 Feb 2018 10:56:05 +0000
Subject: [PATCH 41/60] Plain old classes for typesys

---
 coreapi/codecs/corejson.py    |   4 +-
 coreapi/codecs/jsonschema.py  | 117 ++++++------
 coreapi/codecs/openapi.py     |  27 ++-
 coreapi/schemas/jsonschema.py |  46 ++---
 coreapi/schemas/openapi.py    | 208 +++++++++++----------
 coreapi/typesys.py            | 329 ++++++++++++++--------------------
 tests/codecs/test_openapi.py  |   8 +-
 tests/test_codecs.py          |   4 +-
 8 files changed, 349 insertions(+), 394 deletions(-)

diff --git a/coreapi/codecs/corejson.py b/coreapi/codecs/corejson.py
index dcf2874..da089da 100644
--- a/coreapi/codecs/corejson.py
+++ b/coreapi/codecs/corejson.py
@@ -31,7 +31,7 @@
 
 def encode_schema_to_corejson(schema):
     for cls, type_id in SCHEMA_CLASS_TO_TYPE_ID.items():
-        if issubclass(schema, cls):
+        if isinstance(schema, cls):
             break
     else:
         type_id = 'anything'
@@ -59,7 +59,7 @@ def decode_schema_from_corejson(data):
         kwargs['enum'] = data['enum']
 
     schema_cls = TYPE_ID_TO_SCHEMA_CLASS.get(type_id, typesys.Any)
-    return type(schema_cls.__name__, (schema_cls,), kwargs)
+    return schema_cls(**kwargs)
 
 
 # Robust dictionary lookups, that always return an item of the correct
diff --git a/coreapi/codecs/jsonschema.py b/coreapi/codecs/jsonschema.py
index cd2506e..945944a 100644
--- a/coreapi/codecs/jsonschema.py
+++ b/coreapi/codecs/jsonschema.py
@@ -18,17 +18,17 @@ def decode(self, bytestring, **options):
             )
         except ValueError as exc:
             raise ParseError('Malformed JSON. %s' % exc)
-        jsonschema = JSONSchema(data)
+        jsonschema = JSONSchema.validate(data)
         return self.decode_from_data_structure(jsonschema)
 
     def decode_from_data_structure(self, struct):
         attrs = {}
 
-        if '$ref' in struct:
-            if struct['$ref'] == '#':
-                return typesys.ref()
-            name = struct['$ref'].split('/')[-1]
-            return typesys.ref(name)
+        # if '$ref' in struct:
+        #     if struct['$ref'] == '#':
+        #         return typesys.ref()
+        #     name = struct['$ref'].split('/')[-1]
+        #     return typesys.ref(name)
 
         if struct['type'] == 'string':
             if 'minLength' in struct:
@@ -39,7 +39,7 @@ def decode_from_data_structure(self, struct):
                 attrs['pattern'] = struct['pattern']
             if 'format' in struct:
                 attrs['format'] = struct['format']
-            return typesys.string(**attrs)
+            return typesys.String(**attrs)
 
         if struct['type'] in ['number', 'integer']:
             if 'minimum' in struct:
@@ -55,11 +55,11 @@ def decode_from_data_structure(self, struct):
             if 'format' in struct:
                 attrs['format'] = struct['format']
             if struct['type'] == 'integer':
-                return typesys.integer(**attrs)
-            return typesys.number(**attrs)
+                return typesys.Integer(**attrs)
+            return typesys.Number(**attrs)
 
         if struct['type'] == 'boolean':
-            return typesys.boolean()
+            return typesys.Boolean()
 
         if struct['type'] == 'object':
             if 'properties' in struct:
@@ -69,7 +69,7 @@ def decode_from_data_structure(self, struct):
                 }
             if 'required' in struct:
                 attrs['required'] = struct['required']
-            return typesys.obj(**attrs)
+            return typesys.Object(**attrs)
 
         if struct['type'] == 'array':
             if 'items' in struct:
@@ -82,10 +82,10 @@ def decode_from_data_structure(self, struct):
                 attrs['max_items'] = struct['maxItems']
             if 'uniqueItems' in struct:
                 attrs['unique_items'] = struct['uniqueItems']
-            return typesys.array(**attrs)
+            return typesys.Array(**attrs)
 
-    def encode(self, cls, **options):
-        struct = self.encode_to_data_structure(cls)
+    def encode(self, item, **options):
+        struct = self.encode_to_data_structure(item)
         indent = options.get('indent')
         if indent:
             kwargs = {
@@ -101,70 +101,65 @@ def encode(self, cls, **options):
             }
         return force_bytes(json.dumps(struct, **kwargs))
 
-    def encode_to_data_structure(self, cls):
-        if issubclass(cls, typesys.String):
+    def encode_to_data_structure(self, item):
+        if isinstance(item, typesys.String):
             value = {'type': 'string'}
-            if cls.max_length is not None:
-                value['maxLength'] = cls.max_length
-            if cls.min_length is not None:
-                value['minLength'] = cls.min_length
-            if cls.pattern is not None:
-                value['pattern'] = cls.pattern
-            if cls.format is not None:
-                value['format'] = cls.format
+            if item.max_length is not None:
+                value['maxLength'] = item.max_length
+            if item.min_length is not None:
+                value['minLength'] = item.min_length
+            if item.pattern is not None:
+                value['pattern'] = item.pattern
+            if item.format is not None:
+                value['format'] = item.format
             return value
 
-        if issubclass(cls, typesys.NumericType):
-            if issubclass(cls, typesys.Integer):
+        if isinstance(item, typesys.NumericType):
+            if isinstance(item, typesys.Integer):
                 value = {'type': 'integer'}
             else:
                 value = {'type': 'number'}
 
-            if cls.minimum is not None:
-                value['minimum'] = cls.minimum
-            if cls.maximum is not None:
-                value['maximum'] = cls.maximum
-            if cls.exclusive_minimum:
-                value['exclusiveMinimum'] = cls.exclusive_minimum
-            if cls.exclusive_maximum:
-                value['exclusiveMaximum'] = cls.exclusive_maximum
-            if cls.multiple_of is not None:
-                value['multipleOf'] = cls.multiple_of
-            if cls.format is not None:
-                value['format'] = cls.format
+            if item.minimum is not None:
+                value['minimum'] = item.minimum
+            if item.maximum is not None:
+                value['maximum'] = item.maximum
+            if item.exclusive_minimum:
+                value['exclusiveMinimum'] = item.exclusive_minimum
+            if item.exclusive_maximum:
+                value['exclusiveMaximum'] = item.exclusive_maximum
+            if item.multiple_of is not None:
+                value['multipleOf'] = item.multiple_of
+            if item.format is not None:
+                value['format'] = item.format
             return value
 
-        if issubclass(cls, typesys.Boolean):
+        if isinstance(item, typesys.Boolean):
             return {'type': 'boolean'}
 
-        if issubclass(cls, typesys.Object):
+        if isinstance(item, typesys.Object):
             value = {'type': 'object'}
-            if cls.properties:
+            if item.properties:
                 value['properties'] = {
                     key: self.encode_to_data_structure(value)
-                    for key, value in cls.properties.items()
+                    for key, value in item.properties.items()
                 }
-            if cls.required:
-                value['required'] = cls.required
+            if item.required:
+                value['required'] = item.required
             return value
 
-        if issubclass(cls, typesys.Array):
+        if isinstance(item, typesys.Array):
             value = {'type': 'array'}
-            if cls.items is not None:
-                value['items'] = self.encode_to_data_structure(cls.items)
-            if cls.additional_items:
-                value['additionalItems'] = cls.additional_items
-            if cls.min_items is not None:
-                value['minItems'] = cls.min_items
-            if cls.max_items is not None:
-                value['maxItems'] = cls.max_items
-            if cls.unique_items is not None:
-                value['uniqueItems'] = cls.unique_items
+            if item.items is not None:
+                value['items'] = self.encode_to_data_structure(item.items)
+            if item.additional_items:
+                value['additionalItems'] = item.additional_items
+            if item.min_items is not None:
+                value['minItems'] = item.min_items
+            if item.max_items is not None:
+                value['maxItems'] = item.max_items
+            if item.unique_items is not None:
+                value['uniqueItems'] = item.unique_items
             return value
 
-        if issubclass(cls, typesys.Ref):
-            if not cls.to:
-                return {'$ref': '#'}
-            return {'$ref': '#/definitions/%s' % cls.to}
-
-        raise Exception('Cannot encode class %s' % cls)
+        raise Exception('Cannot encode item %s' % item)
diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
index 4bdd15f..ee360f4 100644
--- a/coreapi/codecs/openapi.py
+++ b/coreapi/codecs/openapi.py
@@ -11,6 +11,15 @@
 ]
 
 
+def lookup(value, keys, default=None):
+    for key in keys:
+        try:
+            value = value[key]
+        except (KeyError, IndexError, TypeError):
+            return default
+    return value
+
+
 def _relative_url(base_url, url):
     """
     Return a graceful link for a URL relative to a base URL.
@@ -35,11 +44,11 @@ def decode(self, bytestring, **options):
         except ValueError as exc:
             raise ParseError('Malformed JSON. %s' % exc)
 
-        openapi = OpenAPI(data)
-        title = openapi.lookup(['info', 'title'])
-        description = openapi.lookup(['info', 'description'])
-        version = openapi.lookup(['info', 'version'])
-        base_url = openapi.lookup(['servers', 0, 'url'])
+        openapi = OpenAPI.validate(data)
+        title = lookup(openapi, ['info', 'title'])
+        description = lookup(openapi, ['info', 'description'])
+        version = lookup(openapi, ['info', 'version'])
+        base_url = lookup(openapi, ['servers', 0, 'url'])
         content = self.get_links(openapi, base_url)
         return Document(title=title, description=description, version=version, url=base_url, content=content)
 
@@ -56,7 +65,7 @@ def get_links(self, openapi, base_url):
             }
             for operation, operation_info in operations.items():
                 operationId = operation_info.get('operationId')
-                tag = operation_info.lookup(['tags', 0])
+                tag = lookup(operation_info, ['tags', 0])
                 if not operationId:
                     continue
 
@@ -79,8 +88,8 @@ def get_link(self, base_url, path, path_info, operation, operation_info):
         description = operation_info.get('description')
 
         # Allow path info and operation info to override the base url.
-        base_url = path_info.lookup(['servers', 0, 'url'], default=base_url)
-        base_url = operation_info.lookup(['servers', 0, 'url'], default=base_url)
+        base_url = lookup(path_info, ['servers', 0, 'url'], default=base_url)
+        base_url = lookup(operation_info, ['servers', 0, 'url'], default=base_url)
 
         # Parameters are taken both from the path info, and from the operation.
         parameters = path_info.get('parameters', [])
@@ -124,7 +133,7 @@ def get_field(self, parameter):
 
     def encode(self, document, **options):
         paths = self.get_paths(document)
-        openapi = OpenAPI({
+        openapi = OpenAPI.validate({
             'openapi': '3.0.0',
             'info': {
                 'version': document.version,
diff --git a/coreapi/schemas/jsonschema.py b/coreapi/schemas/jsonschema.py
index 959eccf..84b3bb5 100644
--- a/coreapi/schemas/jsonschema.py
+++ b/coreapi/schemas/jsonschema.py
@@ -1,34 +1,34 @@
 from coreapi import typesys
-from coreapi.compat import dict_type
 
 
-class JSONSchema(typesys.Object):
-    properties = dict_type([
-        ('$ref', typesys.string()),
-        ('type', typesys.string()),
-        ('enum', typesys.Any),
+JSONSchema = typesys.Object(
+    properties=[
+        ('$ref', typesys.String()),
+        ('type', typesys.String()),
+        ('enum', typesys.Any()),
 
         # String
-        ('minLength', typesys.integer(minimum=0, default=0)),
-        ('maxLength', typesys.integer(minimum=0)),
-        ('pattern', typesys.string(format='regex')),
-        ('format', typesys.string()),
+        ('minLength', typesys.Integer(minimum=0, default=0)),
+        ('maxLength', typesys.Integer(minimum=0)),
+        ('pattern', typesys.String(format='regex')),
+        ('format', typesys.String()),
 
         # Numeric
-        ('minimum', typesys.number()),
-        ('maximum', typesys.number()),
-        ('exclusiveMinimum', typesys.boolean(default=False)),
-        ('exclusiveMaximum', typesys.boolean(default=False)),
-        ('multipleOf', typesys.number(minimum=0.0, exclusive_minimum=True)),
+        ('minimum', typesys.Number()),
+        ('maximum', typesys.Number()),
+        ('exclusiveMinimum', typesys.Boolean(default=False)),
+        ('exclusiveMaximum', typesys.Boolean(default=False)),
+        ('multipleOf', typesys.Number(minimum=0.0, exclusive_minimum=True)),
 
         # Object
-        ('properties', typesys.obj()),  # TODO: typesys.ref('JSONSchema'),
-        ('required', typesys.array(items=typesys.string(), min_items=1, unique=True)),
+        ('properties', typesys.Object()),  # TODO: typesys.ref('JSONSchema'),
+        ('required', typesys.Array(items=typesys.String(), min_items=1, unique_items=True)),
 
         # Array
-        ('items', typesys.obj()),  # TODO: typesys.ref('JSONSchema'),
-        ('additionalItems', typesys.boolean()),
-        ('minItems', typesys.integer(minimum=0)),
-        ('maxItems', typesys.integer(minimum=0)),
-        ('uniqueItems', typesys.boolean()),
-    ])
+        ('items', typesys.Object()),  # TODO: typesys.ref('JSONSchema'),
+        ('additionalItems', typesys.Boolean()),
+        ('minItems', typesys.Integer(minimum=0)),
+        ('maxItems', typesys.Integer(minimum=0)),
+        ('uniqueItems', typesys.Boolean()),
+    ]
+)
diff --git a/coreapi/schemas/openapi.py b/coreapi/schemas/openapi.py
index 3eb22ed..df5f76d 100644
--- a/coreapi/schemas/openapi.py
+++ b/coreapi/schemas/openapi.py
@@ -1,102 +1,110 @@
 from coreapi import typesys
-from coreapi.compat import dict_type
 from coreapi.schemas import JSONSchema
 
 
-class Contact(typesys.Object):
-    properties = dict_type([
-        ('name', typesys.string()),
-        ('url', typesys.string(format='url')),
-        ('email', typesys.string(format='email'))
-    ])
+Contact = typesys.Object(
+    properties=[
+        ('name', typesys.String()),
+        ('url', typesys.String(format='url')),
+        ('email', typesys.String(format='email'))
+    ]
+)
 
 
-class License(typesys.Object):
-    properties = dict_type([
-        ('name', typesys.string()),
-        ('url', typesys.string(format='url'))
-    ])
-    required = ['name']
+License = typesys.Object(
+    properties=[
+        ('name', typesys.String()),
+        ('url', typesys.String(format='url'))
+    ],
+    required=['name']
+)
 
 
-class Info(typesys.Object):
-    properties = dict_type([
-        ('title', typesys.string()),
-        ('description', typesys.string(format='textarea')),
-        ('termsOfService', typesys.string(format='url')),
+Info = typesys.Object(
+    properties=[
+        ('title', typesys.String()),
+        ('description', typesys.String(format='textarea')),
+        ('termsOfService', typesys.String(format='url')),
         ('contact', Contact),
         ('license', License),
-        ('version', typesys.string())
-    ])
-    required = ['title', 'version']
-
-
-class ServerVariable(typesys.Object):
-    properties = dict_type([
-        ('enum', typesys.array(items=typesys.string())),
-        ('default', typesys.string()),
-        ('description', typesys.string(format='textarea'))
-    ])
-    required = ['default']
-
-
-class Server(typesys.Object):
-    properties = dict_type([
-        ('url', typesys.string()),
-        ('description', typesys.string(format='textarea')),
-        ('variables', typesys.obj(additional_properties=ServerVariable))
-    ])
-    required = ['url']
-
-
-class ExternalDocs(typesys.Object):
-    properties = dict_type([
-        ('description', typesys.string(format='textarea')),
-        ('url', typesys.string(format='url'))
-    ])
-    required = ['url']
-
-
-class SecurityRequirement(typesys.Object):
-    additional_properties = typesys.array(items=typesys.string())
-
-
-class Parameter(typesys.Object):
-    properties = dict_type([
-        ('name', typesys.string()),
-        ('in', typesys.string(enum=['query', 'header', 'path', 'cookie'])),
-        ('description', typesys.string(format='textarea')),
-        ('required', typesys.boolean()),
-        ('deprecated', typesys.boolean()),
-        ('allowEmptyValue', typesys.boolean()),
+        ('version', typesys.String())
+    ],
+    required=['title', 'version']
+)
+
+
+ServerVariable = typesys.Object(
+    properties=[
+        ('enum', typesys.Array(items=typesys.String())),
+        ('default', typesys.String()),
+        ('description', typesys.String(format='textarea'))
+    ],
+    required=['default']
+)
+
+
+Server = typesys.Object(
+    properties=[
+        ('url', typesys.String()),
+        ('description', typesys.String(format='textarea')),
+        ('variables', typesys.Object(additional_properties=ServerVariable))
+    ],
+    required=['url']
+)
+
+
+ExternalDocs = typesys.Object(
+    properties=[
+        ('description', typesys.String(format='textarea')),
+        ('url', typesys.String(format='url'))
+    ],
+    required=['url']
+)
+
+
+SecurityRequirement = typesys.Object(
+    additional_properties=typesys.Array(items=typesys.String())
+)
+
+
+Parameter = typesys.Object(
+    properties=[
+        ('name', typesys.String()),
+        ('in', typesys.String(enum=['query', 'header', 'path', 'cookie'])),
+        ('description', typesys.String(format='textarea')),
+        ('required', typesys.Boolean()),
+        ('deprecated', typesys.Boolean()),
+        ('allowEmptyValue', typesys.Boolean()),
         ('schema', JSONSchema),
-        ('example', typesys.Any)
+        ('example', typesys.Any())
         # TODO: Other fields
-    ])
-    required = ['name', 'in']
+    ],
+    required=['name', 'in']
+)
 
 
-class Operation(typesys.Object):
-    properties = dict_type([
-        ('tags', typesys.array(items=typesys.string())),
-        ('summary', typesys.string()),
-        ('description', typesys.string(format='textarea')),
+Operation = typesys.Object(
+    properties=[
+        ('tags', typesys.Array(items=typesys.String())),
+        ('summary', typesys.String()),
+        ('description', typesys.String(format='textarea')),
         ('externalDocs', ExternalDocs),
-        ('operationId', typesys.string()),
-        ('parameters', typesys.array(items=Parameter)),  # TODO: Parameter | ReferenceObject
+        ('operationId', typesys.String()),
+        ('parameters', typesys.Array(items=Parameter)),  # TODO: Parameter | ReferenceObject
         # TODO: 'requestBody'
         # TODO: 'responses'
         # TODO: 'callbacks'
-        ('deprecated', typesys.boolean()),
+        ('deprecated', typesys.Boolean()),
         ('security', SecurityRequirement),
-        ('servers', typesys.array(items=Server))
-    ])
+        ('servers', typesys.Array(items=Server))
+    ]
+)
 
 
-class Path(typesys.Object):
-    properties = dict_type([
-        ('summary', typesys.string()),
-        ('description', typesys.string(format='textarea')),
+Path = typesys.Object(
+    properties=[
+        ('summary', typesys.String()),
+        ('description', typesys.String(format='textarea')),
         ('get', Operation),
         ('put', Operation),
         ('post', Operation),
@@ -105,35 +113,39 @@ class Path(typesys.Object):
         ('head', Operation),
         ('patch', Operation),
         ('trace', Operation),
-        ('servers', typesys.array(items=Server)),
-        ('parameters', typesys.array(items=Parameter))  # TODO: Parameter | ReferenceObject
-    ])
+        ('servers', typesys.Array(items=Server)),
+        ('parameters', typesys.Array(items=Parameter))  # TODO: Parameter | ReferenceObject
+    ]
+)
 
 
-class Paths(typesys.Object):
-    pattern_properties = {
-        '^/': Path  # TODO: Path | ReferenceObject
-    }
+Paths = typesys.Object(
+    pattern_properties=[
+        ('^/', Path)  # TODO: Path | ReferenceObject
+    ]
+)
 
 
-class Tag(typesys.Object):
-    properties = dict_type([
-        ('name', typesys.string()),
-        ('description', typesys.string(format='textarea')),
+Tag = typesys.Object(
+    properties=[
+        ('name', typesys.String()),
+        ('description', typesys.String(format='textarea')),
         ('externalDocs', ExternalDocs)
-    ])
-    required = ['name']
+    ],
+    required=['name']
+)
 
 
-class OpenAPI(typesys.Object):
-    properties = dict_type([
-        ('openapi', typesys.string()),
+OpenAPI = typesys.Object(
+    properties=[
+        ('openapi', typesys.String()),
         ('info', Info),
-        ('servers', typesys.array(items=Server)),
+        ('servers', typesys.Array(items=Server)),
         ('paths', Paths),
         # TODO: 'components': ...,
         ('security', SecurityRequirement),
-        ('tags', typesys.array(items=Tag)),
+        ('tags', typesys.Array(items=Tag)),
         ('externalDocs', ExternalDocs)
-    ])
-    required = ['openapi', 'info']
+    ],
+    required=['openapi', 'info']
+)
diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index 6958816..0795b34 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -21,7 +21,27 @@ def __init__(self, detail):
         super(ValidationError, self).__init__(detail)
 
 
-class String(str):
+class Validator(object):
+    errors = {}
+
+    def __init__(self, title='', description='', default=None, definitions=None):
+        self.title = title
+        self.description = description
+        self.default = default
+        self.definitions = {} if (definitions is None) else definitions
+
+    def validate(value):
+        raise NotImplementedError()
+
+    def error(self, code):
+        message = self.error_message(code)
+        raise ValidationError(message)
+
+    def error_message(self, code):
+        return self.errors[code].format(**self.__dict__)
+
+
+class String(Validator):
     errors = {
         'type': 'Must be a string.',
         'blank': 'Must not be blank.',
@@ -32,51 +52,43 @@ class String(str):
         'enum': 'Must be a valid choice.',
         'exact': 'Must be {exact}.'
     }
-    title = None  # type: str
-    description = None  # type: str
-    max_length = None  # type: int
-    min_length = None  # type: int
-    pattern = None  # type: str
-    format = None  # type: Any
-    enum = None  # type: List[str]
-    trim_whitespace = True
-
-    def __new__(cls, value):
-        value = str.__new__(cls, value)
-
-        if cls.trim_whitespace:
-            value = value.strip()
-
-        if cls.enum is not None:
-            if value not in cls.enum:
-                if len(cls.enum) == 1:
-                    cls.error('exact')
-                cls.error('enum')
-
-        if cls.min_length is not None:
-            if len(value) < cls.min_length:
-                if cls.min_length == 1:
-                    cls.error('blank')
+
+    def __init__(self, max_length=None, min_length=None, pattern=None, enum=None, format=None, **kwargs):
+        super(String, self).__init__(**kwargs)
+        self.max_length = max_length
+        self.min_length = min_length
+        self.pattern = pattern
+        self.enum = enum
+        self.format = format
+
+    def validate(self, value):
+        value = str(value)
+
+        if self.enum is not None:
+            if value not in self.enum:
+                if len(self.enum) == 1:
+                    self.error('exact')
+                self.error('enum')
+
+        if self.min_length is not None:
+            if len(value) < self.min_length:
+                if self.min_length == 1:
+                    self.error('blank')
                 else:
-                    cls.error('min_length')
+                    self.error('min_length')
 
-        if cls.max_length is not None:
-            if len(value) > cls.max_length:
-                cls.error('max_length')
+        if self.max_length is not None:
+            if len(value) > self.max_length:
+                self.error('max_length')
 
-        if cls.pattern is not None:
-            if not re.search(cls.pattern, value):
-                cls.error('pattern')
+        if self.pattern is not None:
+            if not re.search(self.pattern, value):
+                self.error('pattern')
 
         return value
 
-    @classmethod
-    def error(cls, code):
-        message = cls.errors[code].format(**cls.__dict__)
-        raise ValidationError(message)  # from None
-
 
-class NumericType(object):
+class NumericType(Validator):
     """
     Base class for both `Number` and `Integer`.
     """
@@ -89,78 +101,73 @@ class NumericType(object):
         'exclusive_maximum': 'Must be less than {maximum}.',
         'multiple_of': 'Must be a multiple of {multiple_of}.',
     }
-    title = None  # type: str
-    description = None  # type: str
-    enum = None  # type: List[Union[float, int]]
-    minimum = None  # type: Union[float, int]
-    maximum = None  # type: Union[float, int]
-    exclusive_minimum = False
-    exclusive_maximum = False
-    multiple_of = None  # type: Union[float, int]
-    format = None
-
-    def __new__(cls, value):
+
+    def __init__(self, minimum=None, maximum=None, exclusive_minimum=False, exclusive_maximum=False, multiple_of=None, enum=None, format=None, **kwargs):
+        super(NumericType, self).__init__(**kwargs)
+        self.minimum = minimum
+        self.maximum = maximum
+        self.exclusive_minimum = exclusive_minimum
+        self.exclusive_maximum = exclusive_maximum
+        self.multiple_of = multiple_of
+        self.enum = enum
+        self.format = format
+
+    def validate(self, value):
         try:
-            value = cls.numeric_type.__new__(cls, value)
+            value = self.numeric_type(value)
         except (TypeError, ValueError):
-            cls.error('type')
-
-        if cls.enum is not None:
-            if value not in cls.enum:
-                if len(cls.enum) == 1:
-                    cls.error('exact')
-                cls.error('enum')
-
-        if cls.minimum is not None:
-            if cls.exclusive_minimum:
-                if value <= cls.minimum:
-                    cls.error('exclusive_minimum')
+            self.error('type')
+
+        if self.enum is not None:
+            if value not in self.enum:
+                if len(self.enum) == 1:
+                    self.error('exact')
+                self.error('enum')
+
+        if self.minimum is not None:
+            if self.exclusive_minimum:
+                if value <= self.minimum:
+                    self.error('exclusive_minimum')
             else:
-                if value < cls.minimum:
-                    cls.error('minimum')
+                if value < self.minimum:
+                    self.error('minimum')
 
-        if cls.maximum is not None:
-            if cls.exclusive_maximum:
-                if value >= cls.maximum:
-                    cls.error('exclusive_maximum')
+        if self.maximum is not None:
+            if self.exclusive_maximum:
+                if value >= self.maximum:
+                    self.error('exclusive_maximum')
             else:
-                if value > cls.maximum:
-                    cls.error('maximum')
+                if value > self.maximum:
+                    self.error('maximum')
 
-        if cls.multiple_of is not None:
-            if isinstance(cls.multiple_of, float):
-                failed = not (value * (1 / cls.multiple_of)).is_integer()
+        if self.multiple_of is not None:
+            if isinstance(self.multiple_of, float):
+                if not (value * (1 / self.multiple_of)).is_integer():
+                    self.error('multiple_of')
             else:
-                failed = value % cls.multiple_of
-            if failed:
-                cls.error('multiple_of')
+                if value % self.multiple_of:
+                    self.error('multiple_of')
 
         return value
 
-    @classmethod
-    def error(cls, code):
-        message = cls.errors[code].format(**cls.__dict__)
-        raise ValidationError(message)  # from None
-
 
-class Number(NumericType, float):
+class Number(NumericType):
     numeric_type = float
 
 
-class Integer(NumericType, int):
+class Integer(NumericType):
     numeric_type = int
 
 
-class Boolean(object):
-    native_type = bool
+class Boolean(Validator):
     errors = {
         'type': 'Must be a valid boolean.'
     }
-    title = None  # type: str
-    description = None  # type: str
 
-    def __new__(cls, value):
-        if isinstance(value, str):
+    def validate(self, value):
+        if isinstance(value, (int, float, bool)):
+            return bool(value)
+        elif isinstance(value, str):
             try:
                 return {
                     'true': True,
@@ -169,31 +176,26 @@ def __new__(cls, value):
                     '0': False
                 }[value.lower()]
             except KeyError:
-                cls.error('type')
-        return bool(value)
-
-    @classmethod
-    def error(cls, code):
-        message = cls.errors[code].format(**cls.__dict__)
-        raise ValidationError(message)  # from None
+                pass
+        self.error('type')
 
 
-class Object(dict_type):
+class Object(Validator):
     errors = {
         'type': 'Must be an object.',
         'invalid_key': 'Object keys must be strings.',
         'required': 'This field is required.',
     }
-    title = None  # type: str
-    description = None  # type: str
-    properties = {}  # type: Dict[str, type]
-    pattern_properties = None  # type: Dict[str, type]
-    additional_properties = None  # type: type
-    required = []
 
-    def __init__(self, value):
-        super(Object, self).__init__()
+    def __init__(self, properties=None, pattern_properties=None, additional_properties=None, required=None, **kwargs):
+        super(Object, self).__init__(**kwargs)
+        self.properties = {} if (properties is None) else dict_type(properties)
+        self.pattern_properties = {} if (pattern_properties is None) else dict_type(pattern_properties)
+        self.additional_properties = additional_properties
+        self.required = [] if (required is None) else required
 
+    def validate(self, value):
+        validated = dict_type()
         try:
             value = dict_type(value)
         except TypeError:
@@ -212,23 +214,19 @@ def __init__(self, value):
                 if key in self.required:
                     errors[key] = self.error_message('required')
             else:
-                # Coerce value into the given schema type if needed.
-                if isinstance(item, child_schema):
-                    self[key] = item
-                else:
-                    try:
-                        self[key] = child_schema(item)
-                    except ValidationError as exc:
-                        errors[key] = exc.detail
+                try:
+                    validated[key] = child_schema.validate(item)
+                except ValidationError as exc:
+                    errors[key] = exc.detail
 
         # Pattern properties
-        if self.pattern_properties is not None:
+        if self.pattern_properties:
             for key in list(value.keys()):
                 for pattern, child_schema in self.pattern_properties.items():
                     if re.search(pattern, key):
                         item = value.pop(key)
                         try:
-                            self[key] = child_schema(item)
+                            validated[key] = child_schema.validate(item)
                         except ValidationError as exc:
                             errors[key] = exc.detail
 
@@ -238,49 +236,34 @@ def __init__(self, value):
             for key in list(value.keys()):
                 item = value.pop(key)
                 try:
-                    self[key] = child_schema(item)
+                    validated[key] = child_schema.validate(item)
                 except ValidationError as exc:
                     errors[key] = exc.detail
 
         if errors:
             raise ValidationError(errors)
 
-    def lookup(self, keys, default=None):
-        try:
-            item = self[keys[0]]
-        except KeyError:
-            return default
-
-        if len(keys) == 1:
-            return item
-        return item.lookup(keys[1:], default)
-
-    @classmethod
-    def error(cls, code):
-        message = cls.errors[code].format(**cls.__dict__)
-        raise ValidationError(message)  # from None
+        return validated
 
-    @classmethod
-    def error_message(cls, code):
-        return cls.errors[code].format(**cls.__dict__)
 
-
-class Array(list):
+class Array(Validator):
     errors = {
         'type': 'Must be a list.',
         'min_items': 'Not enough items.',
         'max_items': 'Too many items.',
         'unique_items': 'This item is not unique.',
     }
-    title = None  # type: str
-    description = None  # type: str
-    items = None  # type: Union[type, List[type]]
-    additional_items = False  # type: bool
-    min_items = None  # type: Optional[int]
-    max_items = None  # type: Optional[int]
-    unique_items = False  # type: bool
-
-    def __init__(self, value):
+
+    def __init__(self, items=None, additional_items=None, min_items=None, max_items=None, unique_items=False, **kwargs):
+        super(Array, self).__init__(**kwargs)
+        self.items = items
+        self.additional_items = additional_items
+        self.min_items = min_items
+        self.max_items = max_items
+        self.unique_items = unique_items
+
+    def validate(self, value):
+        validated = []
         try:
             value = list(value)
         except TypeError:
@@ -306,9 +289,9 @@ def __init__(self, value):
             try:
                 if isinstance(self.items, list):
                     if pos < len(self.items):
-                        item = self.items[pos](item)
+                        item = self.items[pos].validate(item)
                 elif self.items is not None:
-                    item = self.items(item)
+                    item = self.items.validate(item)
 
                 if self.unique_items:
                     if item in seen_items:
@@ -316,60 +299,16 @@ def __init__(self, value):
                     else:
                         seen_items.add(item)
 
-                self.append(item)
+                validated.append(item)
             except ValidationError as exc:
                 errors[pos] = exc.detail
 
         if errors:
             raise ValidationError(errors)
 
-    def lookup(self, keys, default=None):
-        try:
-            item = self[keys[0]]
-        except (TypeError, IndexError):
-            return default
-
-        if len(keys) == 1:
-            return item
-        return item.lookup(keys[1:], default)
-
-    @classmethod
-    def error(cls, code):
-        message = cls.errors[code].format(**cls.__dict__)
-        raise ValidationError(message)  # from None
+        return validated
 
 
-class Any(object):
-    title = None  # type: str
-    description = None  # type: str
-
-    def __new__(self, value):
+class Any(Validator):
+    def validate(self, value):
         return value
-
-
-def string(**kwargs):
-    return type('String', (String,), kwargs)
-
-
-def integer(**kwargs):
-    return type('Integer', (Integer,), kwargs)
-
-
-def number(**kwargs):
-    return type('Number', (Number,), kwargs)
-
-
-def boolean(**kwargs):
-    return type('Boolean', (Boolean,), kwargs)
-
-
-def array(**kwargs):
-    return type('Array', (Array,), kwargs)
-
-
-def obj(**kwargs):
-    return type('Object', (Object,), kwargs)
-
-
-# def ref(to=''):
-#     return type('Ref', (Ref,), {'to': to})
diff --git a/tests/codecs/test_openapi.py b/tests/codecs/test_openapi.py
index 081d80b..a51b05a 100644
--- a/tests/codecs/test_openapi.py
+++ b/tests/codecs/test_openapi.py
@@ -272,7 +272,7 @@ def test_decode_openapi(openapi_codec, petstore_schema):
                             location='query',
                             description='How many items to return at one time (max 100)',
                             required=False,
-                            schema=typesys.integer(format='int32')
+                            schema=typesys.Integer(format='int32')
                         )
                     ]
                 )),
@@ -291,7 +291,7 @@ def test_decode_openapi(openapi_codec, petstore_schema):
                             location='path',
                             description='The id of the pet to retrieve',
                             required=True,
-                            schema=typesys.string()
+                            schema=typesys.String()
                         )
                     ]
                 ))
@@ -317,7 +317,7 @@ def test_encode_openapi(openapi_codec, minimal_petstore_schema):
                             location='query',
                             description='How many items to return at one time (max 100)',
                             required=False,
-                            schema=typesys.integer(format='int32')
+                            schema=typesys.Integer(format='int32')
                         )
                     ]
                 ),
@@ -336,7 +336,7 @@ def test_encode_openapi(openapi_codec, minimal_petstore_schema):
                             location='path',
                             description='The id of the pet to retrieve',
                             required=True,
-                            schema=typesys.string()
+                            schema=typesys.String()
                         )
                     ]
                 )
diff --git a/tests/test_codecs.py b/tests/test_codecs.py
index 5d2f72d..a0d1f44 100644
--- a/tests/test_codecs.py
+++ b/tests/test_codecs.py
@@ -26,8 +26,8 @@ def doc():
                 url='http://example.org/',
                 fields=[
                     Field(name='noschema'),
-                    Field(name='string_example', schema=typesys.string()),
-                    Field(name='enum_example', schema=typesys.string(enum=['a', 'b', 'c'])),
+                    Field(name='string_example', schema=typesys.String()),
+                    Field(name='enum_example', schema=typesys.String(enum=['a', 'b', 'c'])),
                 ]),
             'nested': {'child': Link(url='http://example.org/123')},
             '_type': 'needs escaping'

From 01a0a519fbcf8039fc8e0d35324fbb74497d399e Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 21 Feb 2018 13:17:13 +0000
Subject: [PATCH 42/60] Add typesys.Ref

---
 coreapi/schemas/jsonschema.py |   4 +-
 coreapi/schemas/openapi.py    | 261 ++++++++++++++++------------------
 coreapi/typesys.py            |  46 ++++--
 3 files changed, 156 insertions(+), 155 deletions(-)

diff --git a/coreapi/schemas/jsonschema.py b/coreapi/schemas/jsonschema.py
index 84b3bb5..fb80edb 100644
--- a/coreapi/schemas/jsonschema.py
+++ b/coreapi/schemas/jsonschema.py
@@ -21,11 +21,11 @@
         ('multipleOf', typesys.Number(minimum=0.0, exclusive_minimum=True)),
 
         # Object
-        ('properties', typesys.Object()),  # TODO: typesys.ref('JSONSchema'),
+        ('properties', typesys.Ref()),
         ('required', typesys.Array(items=typesys.String(), min_items=1, unique_items=True)),
 
         # Array
-        ('items', typesys.Object()),  # TODO: typesys.ref('JSONSchema'),
+        ('items', typesys.Ref()),
         ('additionalItems', typesys.Boolean()),
         ('minItems', typesys.Integer(minimum=0)),
         ('maxItems', typesys.Integer(minimum=0)),
diff --git a/coreapi/schemas/openapi.py b/coreapi/schemas/openapi.py
index df5f76d..8ed7c27 100644
--- a/coreapi/schemas/openapi.py
+++ b/coreapi/schemas/openapi.py
@@ -2,150 +2,129 @@
 from coreapi.schemas import JSONSchema
 
 
-Contact = typesys.Object(
-    properties=[
-        ('name', typesys.String()),
-        ('url', typesys.String(format='url')),
-        ('email', typesys.String(format='email'))
-    ]
-)
-
-
-License = typesys.Object(
-    properties=[
-        ('name', typesys.String()),
-        ('url', typesys.String(format='url'))
-    ],
-    required=['name']
-)
-
-
-Info = typesys.Object(
-    properties=[
-        ('title', typesys.String()),
-        ('description', typesys.String(format='textarea')),
-        ('termsOfService', typesys.String(format='url')),
-        ('contact', Contact),
-        ('license', License),
-        ('version', typesys.String())
-    ],
-    required=['title', 'version']
-)
-
-
-ServerVariable = typesys.Object(
-    properties=[
-        ('enum', typesys.Array(items=typesys.String())),
-        ('default', typesys.String()),
-        ('description', typesys.String(format='textarea'))
-    ],
-    required=['default']
-)
-
-
-Server = typesys.Object(
-    properties=[
-        ('url', typesys.String()),
-        ('description', typesys.String(format='textarea')),
-        ('variables', typesys.Object(additional_properties=ServerVariable))
-    ],
-    required=['url']
-)
-
-
-ExternalDocs = typesys.Object(
-    properties=[
-        ('description', typesys.String(format='textarea')),
-        ('url', typesys.String(format='url'))
-    ],
-    required=['url']
-)
-
-
-SecurityRequirement = typesys.Object(
-    additional_properties=typesys.Array(items=typesys.String())
-)
-
-
-Parameter = typesys.Object(
-    properties=[
-        ('name', typesys.String()),
-        ('in', typesys.String(enum=['query', 'header', 'path', 'cookie'])),
-        ('description', typesys.String(format='textarea')),
-        ('required', typesys.Boolean()),
-        ('deprecated', typesys.Boolean()),
-        ('allowEmptyValue', typesys.Boolean()),
-        ('schema', JSONSchema),
-        ('example', typesys.Any())
-        # TODO: Other fields
-    ],
-    required=['name', 'in']
-)
-
-
-Operation = typesys.Object(
-    properties=[
-        ('tags', typesys.Array(items=typesys.String())),
-        ('summary', typesys.String()),
-        ('description', typesys.String(format='textarea')),
-        ('externalDocs', ExternalDocs),
-        ('operationId', typesys.String()),
-        ('parameters', typesys.Array(items=Parameter)),  # TODO: Parameter | ReferenceObject
-        # TODO: 'requestBody'
-        # TODO: 'responses'
-        # TODO: 'callbacks'
-        ('deprecated', typesys.Boolean()),
-        ('security', SecurityRequirement),
-        ('servers', typesys.Array(items=Server))
-    ]
-)
-
-
-Path = typesys.Object(
-    properties=[
-        ('summary', typesys.String()),
-        ('description', typesys.String(format='textarea')),
-        ('get', Operation),
-        ('put', Operation),
-        ('post', Operation),
-        ('delete', Operation),
-        ('options', Operation),
-        ('head', Operation),
-        ('patch', Operation),
-        ('trace', Operation),
-        ('servers', typesys.Array(items=Server)),
-        ('parameters', typesys.Array(items=Parameter))  # TODO: Parameter | ReferenceObject
-    ]
-)
-
-
-Paths = typesys.Object(
-    pattern_properties=[
-        ('^/', Path)  # TODO: Path | ReferenceObject
-    ]
-)
-
-
-Tag = typesys.Object(
-    properties=[
-        ('name', typesys.String()),
-        ('description', typesys.String(format='textarea')),
-        ('externalDocs', ExternalDocs)
-    ],
-    required=['name']
-)
-
-
 OpenAPI = typesys.Object(
+    title='OpenAPI',
     properties=[
         ('openapi', typesys.String()),
-        ('info', Info),
-        ('servers', typesys.Array(items=Server)),
-        ('paths', Paths),
+        ('info', typesys.Ref('Info')),
+        ('servers', typesys.Array(items=typesys.Ref('Server'))),
+        ('paths', typesys.Ref('Paths')),
         # TODO: 'components': ...,
-        ('security', SecurityRequirement),
-        ('tags', typesys.Array(items=Tag)),
-        ('externalDocs', ExternalDocs)
+        ('security', typesys.Ref('SecurityRequirement')),
+        ('tags', typesys.Array(items=typesys.Ref('Tag'))),
+        ('externalDocs', typesys.Ref('ExternalDocumentation'))
     ],
-    required=['openapi', 'info']
+    required=['openapi', 'info'],
+    definitions={
+        'Info': typesys.Object(
+            properties=[
+                ('title', typesys.String()),
+                ('description', typesys.String(format='textarea')),
+                ('termsOfService', typesys.String(format='url')),
+                ('contact', typesys.Ref('Contact')),
+                ('license', typesys.Ref('License')),
+                ('version', typesys.String())
+            ],
+            required=['title', 'version']
+        ),
+        'Contact': typesys.Object(
+            properties=[
+                ('name', typesys.String()),
+                ('url', typesys.String(format='url')),
+                ('email', typesys.String(format='email'))
+            ]
+        ),
+        'License': typesys.Object(
+            properties=[
+                ('name', typesys.String()),
+                ('url', typesys.String(format='url'))
+            ],
+            required=['name']
+        ),
+        'Server': typesys.Object(
+            properties=[
+                ('url', typesys.String()),
+                ('description', typesys.String(format='textarea')),
+                ('variables', typesys.Object(additional_properties=typesys.Ref('ServerVariable')))
+            ],
+            required=['url']
+        ),
+        'ServerVariable': typesys.Object(
+            properties=[
+                ('enum', typesys.Array(items=typesys.String())),
+                ('default', typesys.String()),
+                ('description', typesys.String(format='textarea'))
+            ],
+            required=['default']
+        ),
+        'Paths': typesys.Object(
+            pattern_properties=[
+                ('^/', typesys.Ref('Path'))  # TODO: Path | ReferenceObject
+            ]
+        ),
+        'Path': typesys.Object(
+            properties=[
+                ('summary', typesys.String()),
+                ('description', typesys.String(format='textarea')),
+                ('get', typesys.Ref('Operation')),
+                ('put', typesys.Ref('Operation')),
+                ('post', typesys.Ref('Operation')),
+                ('delete', typesys.Ref('Operation')),
+                ('options', typesys.Ref('Operation')),
+                ('head', typesys.Ref('Operation')),
+                ('patch', typesys.Ref('Operation')),
+                ('trace', typesys.Ref('Operation')),
+                ('servers', typesys.Array(items=typesys.Ref('Server'))),
+                ('parameters', typesys.Array(items=typesys.Ref('Parameter')))  # TODO: Parameter | ReferenceObject
+            ]
+        ),
+        'Operation': typesys.Object(
+            properties=[
+                ('tags', typesys.Array(items=typesys.String())),
+                ('summary', typesys.String()),
+                ('description', typesys.String(format='textarea')),
+                ('externalDocs', typesys.Ref('ExternalDocumentation')),
+                ('operationId', typesys.String()),
+                ('parameters', typesys.Array(items=typesys.Ref('Parameter'))),  # TODO: Parameter | ReferenceObject
+                # TODO: 'requestBody'
+                # TODO: 'responses'
+                # TODO: 'callbacks'
+                ('deprecated', typesys.Boolean()),
+                ('security', typesys.Ref('SecurityRequirement')),
+                ('servers', typesys.Array(items=typesys.Ref('Server')))
+            ]
+        ),
+        'ExternalDocumentation': typesys.Object(
+            properties=[
+                ('description', typesys.String(format='textarea')),
+                ('url', typesys.String(format='url'))
+            ],
+            required=['url']
+        ),
+        'Parameter': typesys.Object(
+            properties=[
+                ('name', typesys.String()),
+                ('in', typesys.String(enum=['query', 'header', 'path', 'cookie'])),
+                ('description', typesys.String(format='textarea')),
+                ('required', typesys.Boolean()),
+                ('deprecated', typesys.Boolean()),
+                ('allowEmptyValue', typesys.Boolean()),
+                ('schema', JSONSchema),
+                ('example', typesys.Any())
+                # TODO: Other fields
+            ],
+            required=['name', 'in']
+        ),
+        'Tag': typesys.Object(
+            properties=[
+                ('name', typesys.String()),
+                ('description', typesys.String(format='textarea')),
+                ('externalDocs', typesys.Ref('ExternalDocumentation'))
+            ],
+            required=['name']
+        ),
+        'SecurityRequirement': typesys.Object(
+            additional_properties=typesys.Array(items=typesys.String())
+        )
+    }
 )
diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index 0795b34..bb74ae6 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -30,7 +30,7 @@ def __init__(self, title='', description='', default=None, definitions=None):
         self.default = default
         self.definitions = {} if (definitions is None) else definitions
 
-    def validate(value):
+    def validate(value, definitions=None):
         raise NotImplementedError()
 
     def error(self, code):
@@ -61,7 +61,7 @@ def __init__(self, max_length=None, min_length=None, pattern=None, enum=None, fo
         self.enum = enum
         self.format = format
 
-    def validate(self, value):
+    def validate(self, value, definitions=None):
         value = str(value)
 
         if self.enum is not None:
@@ -112,7 +112,7 @@ def __init__(self, minimum=None, maximum=None, exclusive_minimum=False, exclusiv
         self.enum = enum
         self.format = format
 
-    def validate(self, value):
+    def validate(self, value, definitions=None):
         try:
             value = self.numeric_type(value)
         except (TypeError, ValueError):
@@ -164,7 +164,7 @@ class Boolean(Validator):
         'type': 'Must be a valid boolean.'
     }
 
-    def validate(self, value):
+    def validate(self, value, definitions=None):
         if isinstance(value, (int, float, bool)):
             return bool(value)
         elif isinstance(value, str):
@@ -194,7 +194,11 @@ def __init__(self, properties=None, pattern_properties=None, additional_properti
         self.additional_properties = additional_properties
         self.required = [] if (required is None) else required
 
-    def validate(self, value):
+    def validate(self, value, definitions=None):
+        if definitions is None:
+            definitions = dict(self.definitions)
+            definitions[''] = self
+
         validated = dict_type()
         try:
             value = dict_type(value)
@@ -215,7 +219,7 @@ def validate(self, value):
                     errors[key] = self.error_message('required')
             else:
                 try:
-                    validated[key] = child_schema.validate(item)
+                    validated[key] = child_schema.validate(item, definitions=definitions)
                 except ValidationError as exc:
                     errors[key] = exc.detail
 
@@ -226,7 +230,7 @@ def validate(self, value):
                     if re.search(pattern, key):
                         item = value.pop(key)
                         try:
-                            validated[key] = child_schema.validate(item)
+                            validated[key] = child_schema.validate(item, definitions=definitions)
                         except ValidationError as exc:
                             errors[key] = exc.detail
 
@@ -236,7 +240,7 @@ def validate(self, value):
             for key in list(value.keys()):
                 item = value.pop(key)
                 try:
-                    validated[key] = child_schema.validate(item)
+                    validated[key] = child_schema.validate(item, definitions=definitions)
                 except ValidationError as exc:
                     errors[key] = exc.detail
 
@@ -262,7 +266,11 @@ def __init__(self, items=None, additional_items=None, min_items=None, max_items=
         self.max_items = max_items
         self.unique_items = unique_items
 
-    def validate(self, value):
+    def validate(self, value, definitions=None):
+        if definitions is None:
+            definitions = dict(self.definitions)
+            definitions[''] = self
+
         validated = []
         try:
             value = list(value)
@@ -289,9 +297,9 @@ def validate(self, value):
             try:
                 if isinstance(self.items, list):
                     if pos < len(self.items):
-                        item = self.items[pos].validate(item)
+                        item = self.items[pos].validate(item, definitions=definitions)
                 elif self.items is not None:
-                    item = self.items.validate(item)
+                    item = self.items.validate(item, definitions=definitions)
 
                 if self.unique_items:
                     if item in seen_items:
@@ -310,5 +318,19 @@ def validate(self, value):
 
 
 class Any(Validator):
-    def validate(self, value):
+    def validate(self, value, definitions=None):
+        # TODO: Validate value matches primitive types
         return value
+
+
+class Ref(Validator):
+    def __init__(self, ref='', **kwargs):
+        super(Ref, self).__init__(**kwargs)
+        self.ref = ref
+
+    def validate(self, value, definitions=None):
+        assert definitions is not None, 'Ref.validate() requires definitions'
+        assert self.ref in definitions, 'Ref "%s" not in definitions' % self.ref
+
+        child_schema = definitions[self.ref]
+        return child_schema.validate(value, definitions=definitions)

From 46a95595a2a0d5b6c7bcbe27d1659d576a801d74 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 21 Feb 2018 14:00:09 +0000
Subject: [PATCH 43/60] assert types on __init__

---
 coreapi/typesys.py | 67 +++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 60 insertions(+), 7 deletions(-)

diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index bb74ae6..841a243 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -1,6 +1,5 @@
 from coreapi.compat import dict_type, string_types
 import re
-# from typing import Any, Dict, List, Optional, Tuple, Union, overload  # noqa
 
 
 # TODO: Error on unknown attributes
@@ -17,18 +16,30 @@
 
 class ValidationError(Exception):
     def __init__(self, detail):
+        assert isinstance(detail, (string_types, dict))
         self.detail = detail
         super(ValidationError, self).__init__(detail)
 
 
+class NoDefault(object):
+    pass
+
+
 class Validator(object):
     errors = {}
 
-    def __init__(self, title='', description='', default=None, definitions=None):
+    def __init__(self, title='', description='', default=NoDefault, definitions=None):
+        definitions = {} if (definitions is None) else dict_type(definitions)
+
+        assert isinstance(title, string_types)
+        assert isinstance(description, string_types)
+        assert all(isinstance(k, string_types) for k in definitions.keys())
+        assert all(isinstance(v, Validator) for v in definitions.values())
+
         self.title = title
         self.description = description
         self.default = default
-        self.definitions = {} if (definitions is None) else definitions
+        self.definitions = definitions
 
     def validate(value, definitions=None):
         raise NotImplementedError()
@@ -40,6 +51,9 @@ def error(self, code):
     def error_message(self, code):
         return self.errors[code].format(**self.__dict__)
 
+    def has_default(self):
+        return self.default is not NoDefault
+
 
 class String(Validator):
     errors = {
@@ -55,6 +69,13 @@ class String(Validator):
 
     def __init__(self, max_length=None, min_length=None, pattern=None, enum=None, format=None, **kwargs):
         super(String, self).__init__(**kwargs)
+
+        assert max_length is None or isinstance(max_length, int)
+        assert min_length is None or isinstance(min_length, int)
+        assert pattern is None or isinstance(pattern, string_types)
+        assert enum is None or isinstance(enum, list) and all([isinstance(i, string_types) for i in enum])
+        assert format is None or isinstance(format, string_types)
+
         self.max_length = max_length
         self.min_length = min_length
         self.pattern = pattern
@@ -104,6 +125,15 @@ class NumericType(Validator):
 
     def __init__(self, minimum=None, maximum=None, exclusive_minimum=False, exclusive_maximum=False, multiple_of=None, enum=None, format=None, **kwargs):
         super(NumericType, self).__init__(**kwargs)
+
+        assert minimum is None or isinstance(minimum, self.numeric_type)
+        assert maximum is None or isinstance(maximum, self.numeric_type)
+        assert isinstance(exclusive_minimum, bool)
+        assert isinstance(exclusive_maximum, bool)
+        assert multiple_of is None or isinstance(multiple_of, self.numeric_type)
+        assert enum is None or isinstance(enum, list) and all([isinstance(i, string_types) for i in enum])
+        assert format is None or isinstance(format, string_types)
+
         self.minimum = minimum
         self.maximum = maximum
         self.exclusive_minimum = exclusive_minimum
@@ -189,10 +219,21 @@ class Object(Validator):
 
     def __init__(self, properties=None, pattern_properties=None, additional_properties=None, required=None, **kwargs):
         super(Object, self).__init__(**kwargs)
-        self.properties = {} if (properties is None) else dict_type(properties)
-        self.pattern_properties = {} if (pattern_properties is None) else dict_type(pattern_properties)
+
+        properties = {} if (properties is None) else dict_type(properties)
+        pattern_properties = {} if (pattern_properties is None) else dict_type(pattern_properties)
+        required = list(required) if isinstance(required, (list, tuple)) else required
+        required = [] if (required is None) else required
+
+        assert all(isinstance(k, string_types) for k in properties.keys())
+        assert all(isinstance(v, Validator) for v in properties.values())
+        assert all(isinstance(k, string_types) for k in pattern_properties.keys())
+        assert all(isinstance(v, Validator) for v in pattern_properties.values())
+
+        self.properties = properties
+        self.pattern_properties = pattern_properties
         self.additional_properties = additional_properties
-        self.required = [] if (required is None) else required
+        self.required = required
 
     def validate(self, value, definitions=None):
         if definitions is None:
@@ -260,6 +301,15 @@ class Array(Validator):
 
     def __init__(self, items=None, additional_items=None, min_items=None, max_items=None, unique_items=False, **kwargs):
         super(Array, self).__init__(**kwargs)
+
+        items = list(items) if isinstance(items, (list, tuple)) else items
+
+        assert items is None or isinstance(items, Validator) or isinstance(items, list) and all(isinstance(i, Validator) for i in items)
+        assert additional_items is None or isinstance(additional_items, (bool, Validator))
+        assert min_items is None or isinstance(min_items, int)
+        assert max_items is None or isinstance(max_items, int)
+        assert isinstance(unique_items, bool)
+
         self.items = items
         self.additional_items = additional_items
         self.min_items = min_items
@@ -280,7 +330,7 @@ def validate(self, value, definitions=None):
         if isinstance(self.items, list) and len(self.items) > 1:
             if len(value) < len(self.items):
                 self.error('min_items')
-            elif len(value) > len(self.items) and not self.additional_items:
+            elif len(value) > len(self.items) and (self.additional_items is False):
                 self.error('max_items')
 
         if self.min_items is not None and len(value) < self.min_items:
@@ -298,6 +348,8 @@ def validate(self, value, definitions=None):
                 if isinstance(self.items, list):
                     if pos < len(self.items):
                         item = self.items[pos].validate(item, definitions=definitions)
+                    elif isinstance(self.additional_items, Validator):
+                        item = self.additional_items.validate(item, definitions=definitions)
                 elif self.items is not None:
                     item = self.items.validate(item, definitions=definitions)
 
@@ -326,6 +378,7 @@ def validate(self, value, definitions=None):
 class Ref(Validator):
     def __init__(self, ref='', **kwargs):
         super(Ref, self).__init__(**kwargs)
+        assert isinstance(ref, string_types)
         self.ref = ref
 
     def validate(self, value, definitions=None):

From f7729921c0264ae748abdef8110be49b598fd42d Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 21 Feb 2018 16:25:08 +0000
Subject: [PATCH 44/60] Tests and refinements to typesys

---
 coreapi/typesys.py           | 97 ++++++++++++++++++++++--------------
 tests/typesys/test_array.py  | 76 ++++++++++++++++++++++++++++
 tests/typesys/test_object.py | 81 ++++++++++++++++++++++++++++++
 3 files changed, 216 insertions(+), 38 deletions(-)
 create mode 100644 tests/typesys/test_array.py
 create mode 100644 tests/typesys/test_object.py

diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index 841a243..de53924 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -83,7 +83,8 @@ def __init__(self, max_length=None, min_length=None, pattern=None, enum=None, fo
         self.format = format
 
     def validate(self, value, definitions=None):
-        value = str(value)
+        if not isinstance(value, string_types):
+            self.error('type')
 
         if self.enum is not None:
             if value not in self.enum:
@@ -115,7 +116,7 @@ class NumericType(Validator):
     """
     numeric_type = None  # type: type
     errors = {
-        'type': 'Must be a valid number.',
+        'type': 'Must be a number.',
         'minimum': 'Must be greater than or equal to {minimum}.',
         'exclusive_minimum': 'Must be greater than {minimum}.',
         'maximum': 'Must be less than or equal to {maximum}.',
@@ -143,11 +144,11 @@ def __init__(self, minimum=None, maximum=None, exclusive_minimum=False, exclusiv
         self.format = format
 
     def validate(self, value, definitions=None):
-        try:
-            value = self.numeric_type(value)
-        except (TypeError, ValueError):
+        if not isinstance(value, (int, float)) or isinstance(value, bool):
             self.error('type')
 
+        value = self.numeric_type(value)
+
         if self.enum is not None:
             if value not in self.enum:
                 if len(self.enum) == 1:
@@ -195,19 +196,9 @@ class Boolean(Validator):
     }
 
     def validate(self, value, definitions=None):
-        if isinstance(value, (int, float, bool)):
-            return bool(value)
-        elif isinstance(value, str):
-            try:
-                return {
-                    'true': True,
-                    'false': False,
-                    '1': True,
-                    '0': False
-                }[value.lower()]
-            except KeyError:
-                pass
-        self.error('type')
+        if not isinstance(value, bool):
+            self.error('type')
+        return value
 
 
 class Object(Validator):
@@ -215,9 +206,13 @@ class Object(Validator):
         'type': 'Must be an object.',
         'invalid_key': 'Object keys must be strings.',
         'required': 'This field is required.',
+        'no_additional_properties': 'Unknown properties are not allowed.',
+        'empty': 'Must not be empty.',
+        'max_properties': 'Must have no more than {max_properties} properties.',
+        'min_properties': 'Must have at least {min_properties} properties.',
     }
 
-    def __init__(self, properties=None, pattern_properties=None, additional_properties=None, required=None, **kwargs):
+    def __init__(self, properties=None, pattern_properties=None, additional_properties=True, min_properties=None, max_properties=None, required=None, **kwargs):
         super(Object, self).__init__(**kwargs)
 
         properties = {} if (properties is None) else dict_type(properties)
@@ -229,10 +224,16 @@ def __init__(self, properties=None, pattern_properties=None, additional_properti
         assert all(isinstance(v, Validator) for v in properties.values())
         assert all(isinstance(k, string_types) for k in pattern_properties.keys())
         assert all(isinstance(v, Validator) for v in pattern_properties.values())
+        assert additional_properties is None or isinstance(additional_properties, (bool, Validator))
+        assert min_properties is None or isinstance(min_properties, int)
+        assert max_properties is None or isinstance(max_properties, int)
+        assert all(isinstance(i, string_types) for i in required)
 
         self.properties = properties
         self.pattern_properties = pattern_properties
         self.additional_properties = additional_properties
+        self.min_properties = min_properties
+        self.max_properties = max_properties
         self.required = required
 
     def validate(self, value, definitions=None):
@@ -240,24 +241,39 @@ def validate(self, value, definitions=None):
             definitions = dict(self.definitions)
             definitions[''] = self
 
-        validated = dict_type()
-        try:
-            value = dict_type(value)
-        except TypeError:
+        if not isinstance(value, dict):
             self.error('type')
 
+        validated = dict_type()
+        value = dict_type(value)
+
         # Ensure all property keys are strings.
         errors = {}
         if any(not isinstance(key, string_types) for key in value.keys()):
             self.error('invalid_key')
 
+        # Min/Max properties
+        if self.min_properties is not None:
+            if len(value) < self.min_properties:
+                if self.min_properties == 1:
+                    self.error('empty')
+                else:
+                    self.error('min_properties')
+        if self.max_properties is not None:
+            if len(value) > self.max_properties:
+                self.error('max_properties')
+
+        # Requried properties
+        for key in self.required:
+            if key not in value:
+                errors[key] = self.error_message('required')
+
         # Properties
         for key, child_schema in self.properties.items():
             try:
                 item = value.pop(key)
             except KeyError:
-                if key in self.required:
-                    errors[key] = self.error_message('required')
+                pass
             else:
                 try:
                     validated[key] = child_schema.validate(item, definitions=definitions)
@@ -276,7 +292,12 @@ def validate(self, value, definitions=None):
                             errors[key] = exc.detail
 
         # Additional properties
-        if self.additional_properties is not None:
+        if self.additional_properties is True:
+            validated.update(value)
+        elif self.additional_properties is False:
+            for key in value.keys():
+                errors[key] = self.error_message('no_additional_properties')
+        elif self.additional_properties is not None:
             child_schema = self.additional_properties
             for key in list(value.keys()):
                 item = value.pop(key)
@@ -293,9 +314,12 @@ def validate(self, value, definitions=None):
 
 class Array(Validator):
     errors = {
-        'type': 'Must be a list.',
-        'min_items': 'Not enough items.',
-        'max_items': 'Too many items.',
+        'type': 'Must be an array.',
+        'empty': 'Must not be empty.',
+        'exact_items': 'Must have {min_items} items.',
+        'min_items': 'Must have at least {min_items} items.',
+        'max_items': 'Must have no more than {max_items} items.',
+        'additional_items': 'May not contain additional items.',
         'unique_items': 'This item is not unique.',
     }
 
@@ -321,22 +345,19 @@ def validate(self, value, definitions=None):
             definitions = dict(self.definitions)
             definitions[''] = self
 
-        validated = []
-        try:
-            value = list(value)
-        except TypeError:
+        if not isinstance(value, list):
             self.error('type')
 
-        if isinstance(self.items, list) and len(self.items) > 1:
-            if len(value) < len(self.items):
-                self.error('min_items')
-            elif len(value) > len(self.items) and (self.additional_items is False):
-                self.error('max_items')
+        validated = []
 
         if self.min_items is not None and len(value) < self.min_items:
+            if self.min_items == 1:
+                self.error('empty')
             self.error('min_items')
         elif self.max_items is not None and len(value) > self.max_items:
             self.error('max_items')
+        elif isinstance(self.items, list) and (self.additional_items is False) and len(value) > len(self.items):
+            self.error('additional_items')
 
         # Ensure all items are of the right type.
         errors = {}
diff --git a/tests/typesys/test_array.py b/tests/typesys/test_array.py
new file mode 100644
index 0000000..50c0545
--- /dev/null
+++ b/tests/typesys/test_array.py
@@ -0,0 +1,76 @@
+from coreapi.typesys import Array, String, Integer, ValidationError
+import pytest
+
+
+def test_array_type():
+    schema = Array()
+    assert schema.validate([]) == []
+    assert schema.validate(['a', 1]) == ['a', 1]
+    with pytest.raises(ValidationError) as exc:
+        schema.validate(1)
+    assert exc.value.detail == 'Must be an array.'
+
+
+def test_array_items():
+    schema = Array(items=String())
+    assert schema.validate([]) == []
+    assert schema.validate(['a', 'b', 'c']) == ['a', 'b', 'c']
+    with pytest.raises(ValidationError) as exc:
+        schema.validate(['a', 'b', 123])
+    assert exc.value.detail == {2: 'Must be a string.'}
+
+
+def test_array_items_as_list():
+    schema = Array(items=[String(), Integer()])
+    assert schema.validate([]) == []
+    assert schema.validate(['a', 123]) == ['a', 123]
+    with pytest.raises(ValidationError) as exc:
+        schema.validate(['a', 'b'])
+    assert exc.value.detail == {1: 'Must be a number.'}
+
+
+def test_array_max_items():
+    schema = Array(max_items=2)
+    assert schema.validate([1, 2]) == [1, 2]
+    with pytest.raises(ValidationError) as exc:
+        schema.validate([1, 2, 3])
+    assert exc.value.detail == 'Must have no more than 2 items.'
+
+
+def test_array_min_items():
+    schema = Array(min_items=2)
+    assert schema.validate([1, 2]) == [1, 2]
+    with pytest.raises(ValidationError) as exc:
+        schema.validate([1])
+    assert exc.value.detail == 'Must have at least 2 items.'
+
+
+def test_array_empty():
+    schema = Array(min_items=1)
+    assert schema.validate([1]) == [1]
+    with pytest.raises(ValidationError) as exc:
+        schema.validate([])
+    assert exc.value.detail == 'Must not be empty.'
+
+
+def test_array_unique_items():
+    schema = Array(unique_items=True)
+    assert schema.validate([1, 2, 3]) == [1, 2, 3]
+    with pytest.raises(ValidationError) as exc:
+        schema.validate([1, 2, 1])
+    assert exc.value.detail == {2: 'This item is not unique.'}
+
+
+def test_array_additional_items_disallowed():
+    schema = Array(items=[String(), Integer()])
+    assert schema.validate(['a', 123, True]) == ['a', 123, True]
+
+    schema = Array(items=[String(), Integer()], additional_items=False)
+    with pytest.raises(ValidationError) as exc:
+        schema.validate(['a', 123, True])
+    assert exc.value.detail == 'May not contain additional items.'
+
+    schema = Array(items=[String(), Integer()], additional_items=Integer())
+    with pytest.raises(ValidationError) as exc:
+        schema.validate(['a', 123, 'c'])
+    assert exc.value.detail == {2: 'Must be a number.'}
diff --git a/tests/typesys/test_object.py b/tests/typesys/test_object.py
new file mode 100644
index 0000000..bcb9bc5
--- /dev/null
+++ b/tests/typesys/test_object.py
@@ -0,0 +1,81 @@
+from coreapi.typesys import Object, Integer, String, ValidationError
+import pytest
+
+
+def test_object_type():
+    schema = Object()
+    assert schema.validate({}) == {}
+    assert schema.validate({'a': 1}) == {'a': 1}
+    with pytest.raises(ValidationError) as exc:
+        schema.validate(1)
+    assert exc.value.detail == 'Must be an object.'
+
+
+def test_object_keys():
+    schema = Object()
+    with pytest.raises(ValidationError) as exc:
+        schema.validate({1: 1})
+    assert exc.value.detail == 'Object keys must be strings.'
+
+
+def test_object_properties():
+    schema = Object(properties={'num': Integer()})
+    with pytest.raises(ValidationError) as exc:
+        schema.validate({'num': 'abc'})
+    assert exc.value.detail == {'num': 'Must be a number.'}
+
+
+def test_object_required():
+    schema = Object(required=['name'])
+    assert schema.validate({'name': 1}) == {'name': 1}
+    with pytest.raises(ValidationError) as exc:
+        schema.validate({})
+    assert exc.value.detail == {'name': 'This field is required.'}
+
+
+def test_object_max_properties():
+    schema = Object(max_properties=2)
+    assert schema.validate({'a': 1, 'b': 2}) == {'a': 1, 'b': 2}
+    with pytest.raises(ValidationError) as exc:
+        schema.validate({'a': 1, 'b': 2, 'c': 3})
+    assert exc.value.detail == 'Must have no more than 2 properties.'
+
+
+def test_object_min_properties():
+    schema = Object(min_properties=2)
+    assert schema.validate({'a': 1, 'b': 2}) == {'a': 1, 'b': 2}
+    with pytest.raises(ValidationError) as exc:
+        assert schema.validate({'a': 1})
+    assert exc.value.detail == 'Must have at least 2 properties.'
+
+
+def test_object_empty():
+    schema = Object(min_properties=1)
+    assert schema.validate({'a': 1}) == {'a': 1}
+    with pytest.raises(ValidationError) as exc:
+        schema.validate({})
+    assert exc.value.detail == 'Must not be empty.'
+
+
+def test_object_pattern_properties():
+    schema = Object(pattern_properties={'^x-': Integer()})
+    assert schema.validate({'x-foo': 123}) == {'x-foo': 123}
+    with pytest.raises(ValidationError) as exc:
+        schema.validate({'x-foo': 'abc'})
+    assert exc.value.detail == {'x-foo': 'Must be a number.'}
+
+
+def test_object_additional_properties_as_boolean():
+    schema = Object(properties={'a': String()}, additional_properties=False)
+    assert schema.validate({'a': 'abc'}) == {'a': 'abc'}
+    with pytest.raises(ValidationError) as exc:
+        schema.validate({'b': 'abc'})
+    assert exc.value.detail == {'b': 'Unknown properties are not allowed.'}
+
+
+def test_object_additional_properties_as_schema():
+    schema = Object(properties={'a': String()}, additional_properties=Integer())
+    assert schema.validate({'a': 'abc'}) == {'a': 'abc'}
+    with pytest.raises(ValidationError) as exc:
+        schema.validate({'b': 'abc'})
+    assert exc.value.detail == {'b': 'Must be a number.'}

From a50e0e3deceb679a7ae527022018be0f69a275ab Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 21 Feb 2018 16:31:58 +0000
Subject: [PATCH 45/60] exact_items validation for Array

---
 coreapi/typesys.py          | 2 ++
 tests/typesys/test_array.py | 8 ++++++++
 2 files changed, 10 insertions(+)

diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index de53924..5a3b34e 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -350,6 +350,8 @@ def validate(self, value, definitions=None):
 
         validated = []
 
+        if self.min_items is not None and self.min_items == self.max_items and len(value) != self.min_items:
+            self.error('exact_items')
         if self.min_items is not None and len(value) < self.min_items:
             if self.min_items == 1:
                 self.error('empty')
diff --git a/tests/typesys/test_array.py b/tests/typesys/test_array.py
index 50c0545..f838e78 100644
--- a/tests/typesys/test_array.py
+++ b/tests/typesys/test_array.py
@@ -53,6 +53,14 @@ def test_array_empty():
     assert exc.value.detail == 'Must not be empty.'
 
 
+def test_array_exact_count():
+    schema = Array(min_items=3, max_items=3)
+    assert schema.validate([1, 2, 3]) == [1, 2, 3]
+    with pytest.raises(ValidationError) as exc:
+        schema.validate([1, 2, 3, 4])
+    assert exc.value.detail == 'Must have 3 items.'
+
+
 def test_array_unique_items():
     schema = Array(unique_items=True)
     assert schema.validate([1, 2, 3]) == [1, 2, 3]

From b56b1d64fcebd765d458f546b3c38762fd65f042 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 21 Feb 2018 16:50:06 +0000
Subject: [PATCH 46/60] Add allow_null to typesys

---
 coreapi/typesys.py           | 54 +++++++++++++++++++++++++++++-------
 tests/typesys/test_array.py  | 10 +++++++
 tests/typesys/test_object.py | 10 +++++++
 3 files changed, 64 insertions(+), 10 deletions(-)

diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index 5a3b34e..b8e7a44 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -58,6 +58,7 @@ def has_default(self):
 class String(Validator):
     errors = {
         'type': 'Must be a string.',
+        'null': 'May not be null.',
         'blank': 'Must not be blank.',
         'max_length': 'Must have no more than {max_length} characters.',
         'min_length': 'Must have at least {min_length} characters.',
@@ -67,7 +68,7 @@ class String(Validator):
         'exact': 'Must be {exact}.'
     }
 
-    def __init__(self, max_length=None, min_length=None, pattern=None, enum=None, format=None, **kwargs):
+    def __init__(self, max_length=None, min_length=None, pattern=None, enum=None, format=None, allow_null=False, **kwargs):
         super(String, self).__init__(**kwargs)
 
         assert max_length is None or isinstance(max_length, int)
@@ -81,9 +82,14 @@ def __init__(self, max_length=None, min_length=None, pattern=None, enum=None, fo
         self.pattern = pattern
         self.enum = enum
         self.format = format
+        self.allow_null = allow_null
 
     def validate(self, value, definitions=None):
-        if not isinstance(value, string_types):
+        if value is None and self.allow_null:
+            return None
+        elif value is None:
+            self.error('null')
+        elif not isinstance(value, string_types):
             self.error('type')
 
         if self.enum is not None:
@@ -117,6 +123,7 @@ class NumericType(Validator):
     numeric_type = None  # type: type
     errors = {
         'type': 'Must be a number.',
+        'null': 'May not be null.',
         'minimum': 'Must be greater than or equal to {minimum}.',
         'exclusive_minimum': 'Must be greater than {minimum}.',
         'maximum': 'Must be less than or equal to {maximum}.',
@@ -124,7 +131,7 @@ class NumericType(Validator):
         'multiple_of': 'Must be a multiple of {multiple_of}.',
     }
 
-    def __init__(self, minimum=None, maximum=None, exclusive_minimum=False, exclusive_maximum=False, multiple_of=None, enum=None, format=None, **kwargs):
+    def __init__(self, minimum=None, maximum=None, exclusive_minimum=False, exclusive_maximum=False, multiple_of=None, enum=None, format=None, allow_null=False, **kwargs):
         super(NumericType, self).__init__(**kwargs)
 
         assert minimum is None or isinstance(minimum, self.numeric_type)
@@ -142,9 +149,14 @@ def __init__(self, minimum=None, maximum=None, exclusive_minimum=False, exclusiv
         self.multiple_of = multiple_of
         self.enum = enum
         self.format = format
+        self.allow_null = allow_null
 
     def validate(self, value, definitions=None):
-        if not isinstance(value, (int, float)) or isinstance(value, bool):
+        if value is None and self.allow_null:
+            return None
+        elif value is None:
+            self.error('null')
+        elif not isinstance(value, (int, float)) or isinstance(value, bool):
             self.error('type')
 
         value = self.numeric_type(value)
@@ -192,11 +204,21 @@ class Integer(NumericType):
 
 class Boolean(Validator):
     errors = {
-        'type': 'Must be a valid boolean.'
+        'type': 'Must be a valid boolean.',
+        'null': 'May not be null.',
     }
 
+    def __init__(self, allow_null=False, **kwargs):
+        super(Boolean, self).__init__(**kwargs)
+
+        self.allow_null = allow_null
+
     def validate(self, value, definitions=None):
-        if not isinstance(value, bool):
+        if value is None and self.allow_null:
+            return None
+        elif value is None:
+            self.error('null')
+        elif not isinstance(value, bool):
             self.error('type')
         return value
 
@@ -204,6 +226,7 @@ def validate(self, value, definitions=None):
 class Object(Validator):
     errors = {
         'type': 'Must be an object.',
+        'null': 'May not be null.',
         'invalid_key': 'Object keys must be strings.',
         'required': 'This field is required.',
         'no_additional_properties': 'Unknown properties are not allowed.',
@@ -212,7 +235,7 @@ class Object(Validator):
         'min_properties': 'Must have at least {min_properties} properties.',
     }
 
-    def __init__(self, properties=None, pattern_properties=None, additional_properties=True, min_properties=None, max_properties=None, required=None, **kwargs):
+    def __init__(self, properties=None, pattern_properties=None, additional_properties=True, min_properties=None, max_properties=None, required=None, allow_null=False, **kwargs):
         super(Object, self).__init__(**kwargs)
 
         properties = {} if (properties is None) else dict_type(properties)
@@ -235,13 +258,18 @@ def __init__(self, properties=None, pattern_properties=None, additional_properti
         self.min_properties = min_properties
         self.max_properties = max_properties
         self.required = required
+        self.allow_null = allow_null
 
     def validate(self, value, definitions=None):
         if definitions is None:
             definitions = dict(self.definitions)
             definitions[''] = self
 
-        if not isinstance(value, dict):
+        if value is None and self.allow_null:
+            return None
+        elif value is None:
+            self.error('null')
+        elif not isinstance(value, dict):
             self.error('type')
 
         validated = dict_type()
@@ -315,6 +343,7 @@ def validate(self, value, definitions=None):
 class Array(Validator):
     errors = {
         'type': 'Must be an array.',
+        'null': 'May not be null.',
         'empty': 'Must not be empty.',
         'exact_items': 'Must have {min_items} items.',
         'min_items': 'Must have at least {min_items} items.',
@@ -323,7 +352,7 @@ class Array(Validator):
         'unique_items': 'This item is not unique.',
     }
 
-    def __init__(self, items=None, additional_items=None, min_items=None, max_items=None, unique_items=False, **kwargs):
+    def __init__(self, items=None, additional_items=None, min_items=None, max_items=None, unique_items=False, allow_null=False, **kwargs):
         super(Array, self).__init__(**kwargs)
 
         items = list(items) if isinstance(items, (list, tuple)) else items
@@ -339,13 +368,18 @@ def __init__(self, items=None, additional_items=None, min_items=None, max_items=
         self.min_items = min_items
         self.max_items = max_items
         self.unique_items = unique_items
+        self.allow_null = allow_null
 
     def validate(self, value, definitions=None):
         if definitions is None:
             definitions = dict(self.definitions)
             definitions[''] = self
 
-        if not isinstance(value, list):
+        if value is None and self.allow_null:
+            return None
+        elif value is None:
+            self.error('null')
+        elif not isinstance(value, list):
             self.error('type')
 
         validated = []
diff --git a/tests/typesys/test_array.py b/tests/typesys/test_array.py
index f838e78..7da67f3 100644
--- a/tests/typesys/test_array.py
+++ b/tests/typesys/test_array.py
@@ -53,6 +53,16 @@ def test_array_empty():
     assert exc.value.detail == 'Must not be empty.'
 
 
+def test_array_null():
+    schema = Array(allow_null=True)
+    assert schema.validate(None) is None
+
+    schema = Array()
+    with pytest.raises(ValidationError) as exc:
+        schema.validate(None)
+    assert exc.value.detail == 'May not be null.'
+
+
 def test_array_exact_count():
     schema = Array(min_items=3, max_items=3)
     assert schema.validate([1, 2, 3]) == [1, 2, 3]
diff --git a/tests/typesys/test_object.py b/tests/typesys/test_object.py
index bcb9bc5..b5539f1 100644
--- a/tests/typesys/test_object.py
+++ b/tests/typesys/test_object.py
@@ -57,6 +57,16 @@ def test_object_empty():
     assert exc.value.detail == 'Must not be empty.'
 
 
+def test_object_null():
+    schema = Object(allow_null=True)
+    assert schema.validate(None) is None
+
+    schema = Object()
+    with pytest.raises(ValidationError) as exc:
+        schema.validate(None)
+    assert exc.value.detail == 'May not be null.'
+
+
 def test_object_pattern_properties():
     schema = Object(pattern_properties={'^x-': Integer()})
     assert schema.validate({'x-foo': 123}) == {'x-foo': 123}

From c58ad81f004657dcf91edb58770b0fbeb158b471 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Thu, 1 Mar 2018 08:54:25 +0000
Subject: [PATCH 47/60] Work on JSON Schema and typesys

---
 coreapi/codecs/jsonschema.py | 198 ++++++++++++++++++++++++-----------
 coreapi/typesys.py           |  61 +++++++++--
 2 files changed, 189 insertions(+), 70 deletions(-)

diff --git a/coreapi/codecs/jsonschema.py b/coreapi/codecs/jsonschema.py
index 945944a..5387a6f 100644
--- a/coreapi/codecs/jsonschema.py
+++ b/coreapi/codecs/jsonschema.py
@@ -1,12 +1,144 @@
 from coreapi import typesys
 from coreapi.codecs.base import BaseCodec
-from coreapi.compat import COMPACT_SEPARATORS, VERBOSE_SEPARATORS, force_bytes
+from coreapi.compat import COMPACT_SEPARATORS, VERBOSE_SEPARATORS, force_bytes, string_types
 from coreapi.exceptions import ParseError
 from coreapi.schemas import JSONSchema
 import collections
 import json
 
 
+def decode(struct):
+    types = get_types(struct)
+    if is_any(types, struct):
+        return typesys.Any()
+
+    allow_null = False
+    if 'null' in types:
+        allow_null = True
+        types.remove('null')
+
+    if len(types) == 1:
+        return load_type(types.pop(), struct, allow_null)
+    else:
+        items = [load_type(typename, struct, False) for typename in types]
+        return typesys.Union(items=items, allow_null=allow_null)
+
+
+def get_types(struct):
+    """
+    Return the valid schema types as a set.
+    """
+    types = struct.get('type', [])
+    if isinstance(types, string_types):
+        types = set([types])
+    else:
+        types = set(types)
+
+    if not types:
+        types = set(['null', 'boolean', 'object', 'array', 'number', 'string'])
+
+    if 'integer' in types and 'number' in types:
+        types.remove('integer')
+
+    return types
+
+
+def is_any(types, struct):
+    """
+    Return true if all types are valid, and there are no type constraints.
+    """
+    ALL_PROPERTY_NAMES = set([
+        'exclusiveMaximum', 'format', 'minItems', 'pattern', 'required',
+        'multipleOf', 'maximum', 'minimum', 'maxItems', 'minLength',
+        'uniqueItems', 'additionalItems', 'maxLength', 'items',
+        'exclusiveMinimum', 'properties', 'additionalProperties',
+        'minProperties', 'maxProperties', 'patternProperties'
+    ])
+    return len(types) == 6 and not set(struct.keys()) & ALL_PROPERTY_NAMES
+
+
+def load_type(typename, struct, allow_null):
+    attrs = {'allow_null': True} if allow_null else {}
+
+    if typename == 'string':
+        if 'minLength' in struct:
+            attrs['min_length'] = struct['minLength']
+        if 'maxLength' in struct:
+            attrs['max_length'] = struct['maxLength']
+        if 'pattern' in struct:
+            attrs['pattern'] = struct['pattern']
+        if 'format' in struct:
+            attrs['format'] = struct['format']
+        return typesys.String(**attrs)
+
+    if typename in ['number', 'integer']:
+        if 'minimum' in struct:
+            attrs['minimum'] = struct['minimum']
+        if 'maximum' in struct:
+            attrs['maximum'] = struct['maximum']
+        if 'exclusiveMinimum' in struct:
+            attrs['exclusive_minimum'] = struct['exclusiveMinimum']
+        if 'exclusiveMaximum' in struct:
+            attrs['exclusive_maximum'] = struct['exclusiveMaximum']
+        if 'multipleOf' in struct:
+            attrs['multiple_of'] = struct['multipleOf']
+        if 'format' in struct:
+            attrs['format'] = struct['format']
+        if typename == 'integer':
+            return typesys.Integer(**attrs)
+        return typesys.Number(**attrs)
+
+    if typename == 'boolean':
+        return typesys.Boolean(**attrs)
+
+    if typename == 'object':
+        if 'properties' in struct:
+            attrs['properties'] = {
+                key: decode(value)
+                for key, value in struct['properties'].items()
+            }
+        if 'required' in struct:
+            attrs['required'] = struct['required']
+        if 'minProperties' in struct:
+            attrs['min_properties'] = struct['minProperties']
+        if 'maxProperties' in struct:
+            attrs['max_properties'] = struct['maxProperties']
+        if 'required' in struct:
+            attrs['required'] = struct['required']
+        if 'patternProperties' in struct:
+            attrs['pattern_properties'] = {
+                key: decode(value)
+                for key, value in struct['patternProperties'].items()
+            }
+        if 'additionalProperties' in struct:
+            if isinstance(struct['additionalProperties'], bool):
+                attrs['additional_properties'] = struct['additionalProperties']
+            else:
+                attrs['additional_properties'] = decode(struct['additionalProperties'])
+        return typesys.Object(**attrs)
+
+    if typename == 'array':
+        if 'items' in struct:
+            if isinstance(struct['items'], list):
+                attrs['items'] = [decode(item) for item in struct['items']]
+            else:
+                attrs['items'] = decode(struct['items'])
+        if 'additionalItems' in struct:
+            if isinstance(struct['additionalItems'], bool):
+                attrs['additional_items'] = struct['additionalItems']
+            else:
+                attrs['additional_items'] = decode(struct['additionalItems'])
+        if 'minItems' in struct:
+            attrs['min_items'] = struct['minItems']
+        if 'maxItems' in struct:
+            attrs['max_items'] = struct['maxItems']
+        if 'uniqueItems' in struct:
+            attrs['unique_items'] = struct['uniqueItems']
+        return typesys.Array(**attrs)
+
+    assert False
+
+
 class JSONSchemaCodec(BaseCodec):
     media_type = 'application/schema+json'
 
@@ -19,70 +151,10 @@ def decode(self, bytestring, **options):
         except ValueError as exc:
             raise ParseError('Malformed JSON. %s' % exc)
         jsonschema = JSONSchema.validate(data)
-        return self.decode_from_data_structure(jsonschema)
+        return decode(jsonschema)
 
     def decode_from_data_structure(self, struct):
-        attrs = {}
-
-        # if '$ref' in struct:
-        #     if struct['$ref'] == '#':
-        #         return typesys.ref()
-        #     name = struct['$ref'].split('/')[-1]
-        #     return typesys.ref(name)
-
-        if struct['type'] == 'string':
-            if 'minLength' in struct:
-                attrs['min_length'] = struct['minLength']
-            if 'maxLength' in struct:
-                attrs['max_length'] = struct['maxLength']
-            if 'pattern' in struct:
-                attrs['pattern'] = struct['pattern']
-            if 'format' in struct:
-                attrs['format'] = struct['format']
-            return typesys.String(**attrs)
-
-        if struct['type'] in ['number', 'integer']:
-            if 'minimum' in struct:
-                attrs['minimum'] = struct['minimum']
-            if 'maximum' in struct:
-                attrs['maximum'] = struct['maximum']
-            if 'exclusiveMinimum' in struct:
-                attrs['exclusiveMinimum'] = struct['exclusiveMinimum']
-            if 'exclusiveMaximum' in struct:
-                attrs['exclusiveMaximum'] = struct['exclusiveMaximum']
-            if 'multipleOf' in struct:
-                attrs['multipleOf'] = struct['multipleOf']
-            if 'format' in struct:
-                attrs['format'] = struct['format']
-            if struct['type'] == 'integer':
-                return typesys.Integer(**attrs)
-            return typesys.Number(**attrs)
-
-        if struct['type'] == 'boolean':
-            return typesys.Boolean()
-
-        if struct['type'] == 'object':
-            if 'properties' in struct:
-                attrs['properties'] = {
-                    key: self.decode_from_data_structure(value)
-                    for key, value in struct['properties'].items()
-                }
-            if 'required' in struct:
-                attrs['required'] = struct['required']
-            return typesys.Object(**attrs)
-
-        if struct['type'] == 'array':
-            if 'items' in struct:
-                attrs['items'] = self.decode_from_data_structure(struct['items'])
-            if 'additionalItems' in struct:
-                attrs['additional_items'] = struct['additionalItems']
-            if 'minItems' in struct:
-                attrs['min_items'] = struct['minItems']
-            if 'maxItems' in struct:
-                attrs['max_items'] = struct['maxItems']
-            if 'uniqueItems' in struct:
-                attrs['unique_items'] = struct['uniqueItems']
-            return typesys.Array(**attrs)
+        return decode(struct)
 
     def encode(self, item, **options):
         struct = self.encode_to_data_structure(item)
diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index b8e7a44..ba8662b 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -25,6 +25,18 @@ class NoDefault(object):
     pass
 
 
+def unbool(element, true=object(), false=object()):
+    # https://github.com/Julian/jsonschema/blob/master/jsonschema/_utils.py
+    """
+    A hack to treat True and False as distinct from 1 and 0 for uniqueness checks.
+    """
+    if element is True:
+        return true
+    elif element is False:
+        return false
+    return element
+
+
 class Validator(object):
     errors = {}
 
@@ -41,9 +53,16 @@ def __init__(self, title='', description='', default=NoDefault, definitions=None
         self.default = default
         self.definitions = definitions
 
-    def validate(value, definitions=None):
+    def validate(self, value, definitions=None):
         raise NotImplementedError()
 
+    def is_valid(self, value):
+        try:
+            self.validate(value)
+        except ValidationError:
+            return False
+        return True
+
     def error(self, code):
         message = self.error_message(code)
         raise ValidationError(message)
@@ -123,6 +142,7 @@ class NumericType(Validator):
     numeric_type = None  # type: type
     errors = {
         'type': 'Must be a number.',
+        'integer': 'Must be an integer.',
         'null': 'May not be null.',
         'minimum': 'Must be greater than or equal to {minimum}.',
         'exclusive_minimum': 'Must be greater than {minimum}.',
@@ -134,11 +154,11 @@ class NumericType(Validator):
     def __init__(self, minimum=None, maximum=None, exclusive_minimum=False, exclusive_maximum=False, multiple_of=None, enum=None, format=None, allow_null=False, **kwargs):
         super(NumericType, self).__init__(**kwargs)
 
-        assert minimum is None or isinstance(minimum, self.numeric_type)
-        assert maximum is None or isinstance(maximum, self.numeric_type)
+        assert minimum is None or isinstance(minimum, (int, float))
+        assert maximum is None or isinstance(maximum, (int, float))
         assert isinstance(exclusive_minimum, bool)
         assert isinstance(exclusive_maximum, bool)
-        assert multiple_of is None or isinstance(multiple_of, self.numeric_type)
+        assert multiple_of is None or isinstance(multiple_of, (int, float))
         assert enum is None or isinstance(enum, list) and all([isinstance(i, string_types) for i in enum])
         assert format is None or isinstance(format, string_types)
 
@@ -158,6 +178,8 @@ def validate(self, value, definitions=None):
             self.error('null')
         elif not isinstance(value, (int, float)) or isinstance(value, bool):
             self.error('type')
+        elif self.numeric_type is int and isinstance(value, float) and not value.is_integer():
+            self.error('integer')
 
         value = self.numeric_type(value)
 
@@ -398,7 +420,7 @@ def validate(self, value, definitions=None):
         # Ensure all items are of the right type.
         errors = {}
         if self.unique_items:
-            seen_items = set()
+            seen_items = []
 
         for pos, item in enumerate(value):
             try:
@@ -411,10 +433,10 @@ def validate(self, value, definitions=None):
                     item = self.items.validate(item, definitions=definitions)
 
                 if self.unique_items:
-                    if item in seen_items:
+                    if unbool(item) in seen_items:
                         self.error('unique_items')
                     else:
-                        seen_items.add(item)
+                        seen_items.append(unbool(item))
 
                 validated.append(item)
             except ValidationError as exc:
@@ -432,6 +454,31 @@ def validate(self, value, definitions=None):
         return value
 
 
+class Union(Validator):
+    errors = {
+        'null': 'Must not be null.',
+        'union': 'Must match one of the union types.'
+    }
+
+    def __init__(self, items, allow_null=False):
+        assert isinstance(items, list) and all(isinstance(i, Validator) for i in items)
+        self.items = list(items)
+        self.allow_null = allow_null
+
+    def validate(self, value, definitions=None):
+        if value is None and self.allow_null:
+            return None
+        elif value is None:
+            self.error('null')
+
+        for item in self.items:
+            try:
+                return item.validate(value)
+            except ValidationError:
+                pass
+        self.error('union')
+
+
 class Ref(Validator):
     def __init__(self, ref='', **kwargs):
         super(Ref, self).__init__(**kwargs)

From 15f24dc6e7a13457a2aa1ef7c66597edc1ce8875 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Thu, 1 Mar 2018 16:46:12 +0000
Subject: [PATCH 48/60] Work on Union and JSONSchema

---
 coreapi/codecs/jsonschema.py  |  3 +-
 coreapi/compat.py             |  7 +++++
 coreapi/schemas/jsonschema.py | 15 ++++++----
 coreapi/typesys.py            | 55 +++++++++++++++++++++++------------
 4 files changed, 56 insertions(+), 24 deletions(-)

diff --git a/coreapi/codecs/jsonschema.py b/coreapi/codecs/jsonschema.py
index 5387a6f..38df4a0 100644
--- a/coreapi/codecs/jsonschema.py
+++ b/coreapi/codecs/jsonschema.py
@@ -154,7 +154,8 @@ def decode(self, bytestring, **options):
         return decode(jsonschema)
 
     def decode_from_data_structure(self, struct):
-        return decode(struct)
+        jsonschema = JSONSchema.validate(struct)
+        return decode(jsonschema)
 
     def encode(self, item, **options):
         struct = self.encode_to_data_structure(item)
diff --git a/coreapi/compat.py b/coreapi/compat.py
index 0d3c46f..a8d5d44 100644
--- a/coreapi/compat.py
+++ b/coreapi/compat.py
@@ -15,6 +15,7 @@
     # Python 2
     import urlparse
     import cookielib as cookiejar
+    import math
 
     string_types = (basestring,)
     text_type = unicode
@@ -25,11 +26,17 @@ def b64encode(input_string):
         # Provide a consistently-as-unicode interface across 2.x and 3.x
         return base64.b64encode(input_string)
 
+    def isfinite(num):
+        if math.isinf(num) or math.isnan(num):
+            return False
+        return True
+
 except ImportError:
     # Python 3
     import urllib.parse as urlparse
     from io import IOBase
     from http import cookiejar
+    from math import isfinite
 
     string_types = (str,)
     text_type = str
diff --git a/coreapi/schemas/jsonschema.py b/coreapi/schemas/jsonschema.py
index fb80edb..c210d9b 100644
--- a/coreapi/schemas/jsonschema.py
+++ b/coreapi/schemas/jsonschema.py
@@ -4,8 +4,9 @@
 JSONSchema = typesys.Object(
     properties=[
         ('$ref', typesys.String()),
-        ('type', typesys.String()),
-        ('enum', typesys.Any()),
+        ('type', typesys.String() | typesys.Array(items=typesys.String())),
+        ('enum', typesys.Array(unique_items=True, min_items=1)),
+        ('definitions', typesys.Object(additional_properties=typesys.Ref())),
 
         # String
         ('minLength', typesys.Integer(minimum=0, default=0)),
@@ -22,12 +23,16 @@
 
         # Object
         ('properties', typesys.Ref()),
+        ('minProperties', typesys.Integer(minimum=0, default=0)),
+        ('maxProperties', typesys.Integer(minimum=0)),
+        ('patternProperties', typesys.Object(additional_properties=typesys.Ref())),
+        ('additionalProperties', typesys.Ref() | typesys.Boolean()),
         ('required', typesys.Array(items=typesys.String(), min_items=1, unique_items=True)),
 
         # Array
-        ('items', typesys.Ref()),
-        ('additionalItems', typesys.Boolean()),
-        ('minItems', typesys.Integer(minimum=0)),
+        ('items', typesys.Ref() | typesys.Array(items=typesys.Ref(), min_items=1)),
+        ('additionalItems', typesys.Ref() | typesys.Boolean()),
+        ('minItems', typesys.Integer(minimum=0, default=9)),
         ('maxItems', typesys.Integer(minimum=0)),
         ('uniqueItems', typesys.Boolean()),
     ]
diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index ba8662b..0c68eb7 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -1,4 +1,4 @@
-from coreapi.compat import dict_type, string_types
+from coreapi.compat import dict_type, isfinite, string_types
 import re
 
 
@@ -73,6 +73,19 @@ def error_message(self, code):
     def has_default(self):
         return self.default is not NoDefault
 
+    def __or__(self, other):
+        if isinstance(self, Union):
+            items = self.items
+        else:
+            items = [self]
+
+        if isinstance(other, Union):
+            items += other.items
+        else:
+            items += [other]
+
+        return Union(items)
+
 
 class String(Validator):
     errors = {
@@ -142,8 +155,9 @@ class NumericType(Validator):
     numeric_type = None  # type: type
     errors = {
         'type': 'Must be a number.',
-        'integer': 'Must be an integer.',
         'null': 'May not be null.',
+        'integer': 'Must be an integer.',
+        'finite': 'Must be finite.',
         'minimum': 'Must be greater than or equal to {minimum}.',
         'exclusive_minimum': 'Must be greater than {minimum}.',
         'maximum': 'Must be less than or equal to {maximum}.',
@@ -178,6 +192,8 @@ def validate(self, value, definitions=None):
             self.error('null')
         elif not isinstance(value, (int, float)) or isinstance(value, bool):
             self.error('type')
+        elif isinstance(value, float) and not isfinite(value):
+            self.error('finite')
         elif self.numeric_type is int and isinstance(value, float) and not value.is_integer():
             self.error('integer')
 
@@ -295,7 +311,6 @@ def validate(self, value, definitions=None):
             self.error('type')
 
         validated = dict_type()
-        value = dict_type(value)
 
         # Ensure all property keys are strings.
         errors = {}
@@ -313,44 +328,48 @@ def validate(self, value, definitions=None):
             if len(value) > self.max_properties:
                 self.error('max_properties')
 
-        # Requried properties
+        # Required properties
         for key in self.required:
             if key not in value:
                 errors[key] = self.error_message('required')
 
         # Properties
         for key, child_schema in self.properties.items():
+            if key not in value:
+                continue
+            item = value[key]
             try:
-                item = value.pop(key)
-            except KeyError:
-                pass
-            else:
-                try:
-                    validated[key] = child_schema.validate(item, definitions=definitions)
-                except ValidationError as exc:
-                    errors[key] = exc.detail
+                validated[key] = child_schema.validate(item, definitions=definitions)
+            except ValidationError as exc:
+                errors[key] = exc.detail
 
         # Pattern properties
         if self.pattern_properties:
             for key in list(value.keys()):
                 for pattern, child_schema in self.pattern_properties.items():
                     if re.search(pattern, key):
-                        item = value.pop(key)
+                        item = value[key]
                         try:
                             validated[key] = child_schema.validate(item, definitions=definitions)
                         except ValidationError as exc:
                             errors[key] = exc.detail
 
         # Additional properties
+        remaining = [
+            key for key in value.keys()
+            if key not in set(validated.keys())
+        ]
+
         if self.additional_properties is True:
-            validated.update(value)
+            for key in remaining:
+                validated[key] = value[key]
         elif self.additional_properties is False:
-            for key in value.keys():
+            for key in remaining:
                 errors[key] = self.error_message('no_additional_properties')
         elif self.additional_properties is not None:
             child_schema = self.additional_properties
-            for key in list(value.keys()):
-                item = value.pop(key)
+            for key in remaining:
+                item = value[key]
                 try:
                     validated[key] = child_schema.validate(item, definitions=definitions)
                 except ValidationError as exc:
@@ -473,7 +492,7 @@ def validate(self, value, definitions=None):
 
         for item in self.items:
             try:
-                return item.validate(value)
+                return item.validate(value, definitions=definitions)
             except ValidationError:
                 pass
         self.error('union')

From cb8e273fdfff7c635a196ad12fb791df12a85e2f Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Thu, 1 Mar 2018 17:22:02 +0000
Subject: [PATCH 49/60] Cleanups on typesys

---
 coreapi/schemas/jsonschema.py |  2 +-
 coreapi/typesys.py            | 32 ++++++++++----------------------
 2 files changed, 11 insertions(+), 23 deletions(-)

diff --git a/coreapi/schemas/jsonschema.py b/coreapi/schemas/jsonschema.py
index c210d9b..55535ea 100644
--- a/coreapi/schemas/jsonschema.py
+++ b/coreapi/schemas/jsonschema.py
@@ -22,7 +22,7 @@
         ('multipleOf', typesys.Number(minimum=0.0, exclusive_minimum=True)),
 
         # Object
-        ('properties', typesys.Ref()),
+        ('properties', typesys.Object(additional_properties=typesys.Ref())),
         ('minProperties', typesys.Integer(minimum=0, default=0)),
         ('maxProperties', typesys.Integer(minimum=0)),
         ('patternProperties', typesys.Object(additional_properties=typesys.Ref())),
diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index 0c68eb7..30a0839 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -2,16 +2,16 @@
 import re
 
 
-# TODO: Error on unknown attributes
-# TODO: allow_blank?
-# TODO: format (check type at start and allow, coerce, .native)
-# TODO: default=empty
-# TODO: check 'required' exists in 'properties'
-# TODO: smarter ordering
-# TODO: extra_properties=False by default
-# TODO: inf, -inf, nan
-# TODO: Overriding errors
-# TODO: Blank booleans as False?
+def unbool(element, true=object(), false=object()):
+    # https://github.com/Julian/jsonschema/blob/master/jsonschema/_utils.py
+    """
+    A hack to treat True and False as distinct from 1 and 0 for uniqueness checks.
+    """
+    if element is True:
+        return true
+    elif element is False:
+        return false
+    return element
 
 
 class ValidationError(Exception):
@@ -25,18 +25,6 @@ class NoDefault(object):
     pass
 
 
-def unbool(element, true=object(), false=object()):
-    # https://github.com/Julian/jsonschema/blob/master/jsonschema/_utils.py
-    """
-    A hack to treat True and False as distinct from 1 and 0 for uniqueness checks.
-    """
-    if element is True:
-        return true
-    elif element is False:
-        return false
-    return element
-
-
 class Validator(object):
     errors = {}
 

From f19c680dc45449abca72c63a74bbaa2454074ccc Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Mon, 5 Mar 2018 11:20:47 +0000
Subject: [PATCH 50/60] Uniqueness checking always that always uses set()

---
 coreapi/typesys.py | 51 +++++++++++++++++++++++++++++-----------------
 1 file changed, 32 insertions(+), 19 deletions(-)

diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index 30a0839..2536926 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -2,15 +2,28 @@
 import re
 
 
-def unbool(element, true=object(), false=object()):
-    # https://github.com/Julian/jsonschema/blob/master/jsonschema/_utils.py
-    """
-    A hack to treat True and False as distinct from 1 and 0 for uniqueness checks.
-    """
+NO_DEFAULT = object()
+TRUE = object()
+FALSE = object()
+
+
+def hashable(element):
+    # Coerce a primitive into a uniquely hashable type, for uniqueness checks.
+
     if element is True:
-        return true
+        return TRUE  # Need to make `True` distinct from `1`.
     elif element is False:
-        return false
+        return FALSE  # Need to make `False` distinct from `0`.
+    elif isinstance(element, list):
+        return ('list', tuple([
+            hashable(item) for item in element
+        ]))
+    elif isinstance(element, dict):
+        return ('dict', tuple([
+            (hashable(key), hashable(value)) for key, value in element.items()
+        ]))
+
+    assert (element is None) or isinstance(element, (int, float, string_types))
     return element
 
 
@@ -21,26 +34,25 @@ def __init__(self, detail):
         super(ValidationError, self).__init__(detail)
 
 
-class NoDefault(object):
-    pass
-
-
 class Validator(object):
     errors = {}
 
-    def __init__(self, title='', description='', default=NoDefault, definitions=None):
+    def __init__(self, title='', description='', default=NO_DEFAULT, definitions=None):
         definitions = {} if (definitions is None) else dict_type(definitions)
 
         assert isinstance(title, string_types)
         assert isinstance(description, string_types)
+        assert isinstance(definitions, dict)
         assert all(isinstance(k, string_types) for k in definitions.keys())
         assert all(isinstance(v, Validator) for v in definitions.values())
 
         self.title = title
         self.description = description
-        self.default = default
         self.definitions = definitions
 
+        if default is not NO_DEFAULT:
+            self.default = default
+
     def validate(self, value, definitions=None):
         raise NotImplementedError()
 
@@ -51,6 +63,9 @@ def is_valid(self, value):
             return False
         return True
 
+    def has_default(self):
+        return hasattr(self, 'default')
+
     def error(self, code):
         message = self.error_message(code)
         raise ValidationError(message)
@@ -58,9 +73,6 @@ def error(self, code):
     def error_message(self, code):
         return self.errors[code].format(**self.__dict__)
 
-    def has_default(self):
-        return self.default is not NoDefault
-
     def __or__(self, other):
         if isinstance(self, Union):
             items = self.items
@@ -427,7 +439,7 @@ def validate(self, value, definitions=None):
         # Ensure all items are of the right type.
         errors = {}
         if self.unique_items:
-            seen_items = []
+            seen_items = set()
 
         for pos, item in enumerate(value):
             try:
@@ -440,10 +452,11 @@ def validate(self, value, definitions=None):
                     item = self.items.validate(item, definitions=definitions)
 
                 if self.unique_items:
-                    if unbool(item) in seen_items:
+                    hashable_item = hashable(item)
+                    if hashable_item in seen_items:
                         self.error('unique_items')
                     else:
-                        seen_items.append(unbool(item))
+                        seen_items.add(hashable_item)
 
                 validated.append(item)
             except ValidationError as exc:

From a87f66a087d6c6b7690ab6cf7d14a2425257b7f2 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Mon, 5 Mar 2018 13:52:32 +0000
Subject: [PATCH 51/60] Add Section, Add Link.id

---
 coreapi/codecs/openapi.py | 34 ++++++++++++++++------------------
 coreapi/document.py       | 25 +++++++++++++++++++++++--
 2 files changed, 39 insertions(+), 20 deletions(-)

diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
index ee360f4..f3bff08 100644
--- a/coreapi/codecs/openapi.py
+++ b/coreapi/codecs/openapi.py
@@ -1,6 +1,6 @@
 from coreapi.codecs import BaseCodec, JSONSchemaCodec
 from coreapi.compat import VERBOSE_SEPARATORS, dict_type, force_bytes, urlparse
-from coreapi.document import Document, Link, Field
+from coreapi.document import Document, Link, Field, Section
 from coreapi.exceptions import ParseError
 from coreapi.schemas import OpenAPI
 import json
@@ -49,14 +49,14 @@ def decode(self, bytestring, **options):
         description = lookup(openapi, ['info', 'description'])
         version = lookup(openapi, ['info', 'version'])
         base_url = lookup(openapi, ['servers', 0, 'url'])
-        content = self.get_links(openapi, base_url)
-        return Document(title=title, description=description, version=version, url=base_url, content=content)
+        sections = self.get_sections(openapi, base_url)
+        return Document(title=title, description=description, version=version, url=base_url, sections=sections)
 
-    def get_links(self, openapi, base_url):
+    def get_sections(self, openapi, base_url):
         """
         Return all the links in the document, layed out by tag and operationId.
         """
-        content = {}
+        links = dict_type()
 
         for path, path_info in openapi.get('paths', {}).items():
             operations = {
@@ -64,26 +64,23 @@ def get_links(self, openapi, base_url):
                 if key in METHODS
             }
             for operation, operation_info in operations.items():
-                operationId = operation_info.get('operationId')
-                tag = lookup(operation_info, ['tags', 0])
-                if not operationId:
-                    continue
-
+                tag = lookup(operation_info, ['tags', 0], default='')
                 link = self.get_link(base_url, path, path_info, operation, operation_info)
-                if tag is None:
-                    content[operationId] = link
-                else:
-                    if tag in content:
-                        content[tag][operationId] = link
-                    else:
-                        content[tag] = {operationId: link}
 
-        return content
+                if tag not in links:
+                    links[tag] = []
+                links[tag].append(link)
+
+        return [
+            Section(id=key, title=key, links=value)
+            for key, value in links.items()
+        ]
 
     def get_link(self, base_url, path, path_info, operation, operation_info):
         """
         Return a single link in the document.
         """
+        id = operation_info.get('operationId')
         title = operation_info.get('summary')
         description = operation_info.get('description')
 
@@ -101,6 +98,7 @@ def get_link(self, base_url, path, path_info, operation, operation_info):
         ]
 
         return Link(
+            id=id,
             url=urlparse.urljoin(base_url, path),
             method=operation,
             title=title,
diff --git a/coreapi/document.py b/coreapi/document.py
index 4dd537e..e4212c9 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -48,7 +48,7 @@ class Document(Mapping):
     Expresses the data that the client may access,
     and the actions that the client may perform.
     """
-    def __init__(self, url=None, title=None, description=None, version=None, media_type=None, content=None):
+    def __init__(self, url=None, title=None, description=None, version=None, media_type=None, content=None, sections=None):
         content = {} if (content is None) else content
 
         if url is not None and not isinstance(url, string_types):
@@ -71,6 +71,18 @@ def __init__(self, url=None, title=None, description=None, version=None, media_t
         self._description = '' if (description is None) else description
         self._version = '' if (version is None) else version
         self._media_type = '' if (media_type is None) else media_type
+
+        if sections:
+            for section in sections:
+                if not section.id:
+                    for link in section.links:
+                        content[link.id] = link
+                else:
+                    content[section.id] = {}
+                    for link in section.links:
+                        content[section.id][link.id] = link
+            self.sections = sections
+
         self._data = {key: _to_objects(value) for key, value in content.items()}
 
     def __iter__(self):
@@ -133,6 +145,14 @@ def links(self):
         ])
 
 
+class Section(object):
+    def __init__(self, id=None, title=None, description=None, links=None):
+        self.id = id
+        self.title = title
+        self.description = description
+        self.links = links
+
+
 class Object(Mapping):
     """
     An immutable mapping of strings to values.
@@ -178,7 +198,7 @@ class Link(object):
     """
     Links represent the actions that a client may perform.
     """
-    def __init__(self, url=None, method=None, encoding=None, title=None, description=None, fields=None, action=None):
+    def __init__(self, url=None, method=None, encoding=None, title=None, description=None, fields=None, action=None, id=None):
         if action is not None:
             method = action  # Deprecated
 
@@ -200,6 +220,7 @@ def __init__(self, url=None, method=None, encoding=None, title=None, description
         ]):
             raise TypeError("Argument 'fields' must be a list of strings or fields.")
 
+        self.id = id
         self._url = '' if (url is None) else url
         self._method = '' if (method is None) else method
         self._encoding = '' if (encoding is None) else encoding

From 382eef832dcb526edff842d3150d86dd3998af36 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Mon, 5 Mar 2018 13:56:42 +0000
Subject: [PATCH 52/60] Slugify tag names to get section ids

---
 coreapi/codecs/openapi.py | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
index f3bff08..bdff499 100644
--- a/coreapi/codecs/openapi.py
+++ b/coreapi/codecs/openapi.py
@@ -4,6 +4,7 @@
 from coreapi.exceptions import ParseError
 from coreapi.schemas import OpenAPI
 import json
+import re
 
 
 METHODS = [
@@ -34,6 +35,13 @@ def _relative_url(base_url, url):
     return url
 
 
+def _simple_slugify(text):
+    text = text.lower()
+    text = re.sub(r'[^a-z0-9]+', '_', text)
+    text = re.sub(r'[_]+', '_', text)
+    return text.strip('_')
+
+
 class OpenAPICodec(BaseCodec):
     media_type = 'application/vnd.oai.openapi'
     format = 'openapi'
@@ -72,7 +80,7 @@ def get_sections(self, openapi, base_url):
                 links[tag].append(link)
 
         return [
-            Section(id=key, title=key, links=value)
+            Section(id=_simple_slugify(key), title=key, links=value)
             for key, value in links.items()
         ]
 

From 4a5993a0e70255988e0cf2e2a8d67972f59907ce Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 6 Mar 2018 10:55:30 +0000
Subject: [PATCH 53/60] Add path_links and query_links to Section

---
 coreapi/document.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/coreapi/document.py b/coreapi/document.py
index e4212c9..f06d476 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -152,6 +152,12 @@ def __init__(self, id=None, title=None, description=None, links=None):
         self.description = description
         self.links = links
 
+    def path_links(self):
+        return [link for link in self.links if link.location == 'path']
+
+    def query_links(self):
+        return [link for link in self.links if link.location == 'query']
+
 
 class Object(Mapping):
     """

From 5e3de6cc90b5e025b9668e10d673288971c904c8 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 6 Mar 2018 10:58:54 +0000
Subject: [PATCH 54/60] Add path_fields and query_fields to Link

---
 coreapi/document.py | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/coreapi/document.py b/coreapi/document.py
index f06d476..5128cf4 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -152,12 +152,6 @@ def __init__(self, id=None, title=None, description=None, links=None):
         self.description = description
         self.links = links
 
-    def path_links(self):
-        return [link for link in self.links if link.location == 'path']
-
-    def query_links(self):
-        return [link for link in self.links if link.location == 'query']
-
 
 class Object(Mapping):
     """
@@ -266,6 +260,12 @@ def action(self):
         # Deprecated
         return self._method
 
+    def path_fields(self):
+        return [field for field in self.fields if field.location == 'path']
+
+    def query_fields(self):
+        return [field for field in self.fields if field.location == 'query']
+
     def __eq__(self, other):
         return (
             isinstance(other, Link) and

From 1d7a121561f3f2b7c5c23e5e35d8319b5e1e1f1f Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 6 Mar 2018 11:12:25 +0000
Subject: [PATCH 55/60] Tweak

---
 coreapi/codecs/openapi.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
index bdff499..46adc59 100644
--- a/coreapi/codecs/openapi.py
+++ b/coreapi/codecs/openapi.py
@@ -80,7 +80,7 @@ def get_sections(self, openapi, base_url):
                 links[tag].append(link)
 
         return [
-            Section(id=_simple_slugify(key), title=key, links=value)
+            Section(id=_simple_slugify(key), title=key.title(), links=value)
             for key, value in links.items()
         ]
 

From 58ec296c0f6deb66a09f98e77436affb72e6275c Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 6 Mar 2018 11:45:26 +0000
Subject: [PATCH 56/60] Fix 'security' in OpenAPI

---
 coreapi/schemas/openapi.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/coreapi/schemas/openapi.py b/coreapi/schemas/openapi.py
index 8ed7c27..e5b77b4 100644
--- a/coreapi/schemas/openapi.py
+++ b/coreapi/schemas/openapi.py
@@ -90,7 +90,7 @@
                 # TODO: 'responses'
                 # TODO: 'callbacks'
                 ('deprecated', typesys.Boolean()),
-                ('security', typesys.Ref('SecurityRequirement')),
+                ('security', typesys.Array(typesys.Ref('SecurityRequirement'))),
                 ('servers', typesys.Array(items=typesys.Ref('Server')))
             ]
         ),

From 947e03bdc75d4f20ea77f083460db454fba4c83e Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 6 Mar 2018 12:09:22 +0000
Subject: [PATCH 57/60] If no operationId then use summary for Link.id

---
 coreapi/codecs/openapi.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
index 46adc59..0d5f439 100644
--- a/coreapi/codecs/openapi.py
+++ b/coreapi/codecs/openapi.py
@@ -74,6 +74,8 @@ def get_sections(self, openapi, base_url):
             for operation, operation_info in operations.items():
                 tag = lookup(operation_info, ['tags', 0], default='')
                 link = self.get_link(base_url, path, path_info, operation, operation_info)
+                if link is None:
+                    continue
 
                 if tag not in links:
                     links[tag] = []
@@ -92,6 +94,11 @@ def get_link(self, base_url, path, path_info, operation, operation_info):
         title = operation_info.get('summary')
         description = operation_info.get('description')
 
+        if id is None:
+            id = _simple_slugify(title)
+            if not id:
+                return None
+
         # Allow path info and operation info to override the base url.
         base_url = lookup(path_info, ['servers', 0, 'url'], default=base_url)
         base_url = lookup(operation_info, ['servers', 0, 'url'], default=base_url)

From 7486932af20ce241a42b4f3f2b13e8787a9f6c3f Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 6 Mar 2018 13:27:11 +0000
Subject: [PATCH 58/60] Building out OpenAPI v3 spec

---
 coreapi/schemas/openapi.py | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/coreapi/schemas/openapi.py b/coreapi/schemas/openapi.py
index e5b77b4..292a888 100644
--- a/coreapi/schemas/openapi.py
+++ b/coreapi/schemas/openapi.py
@@ -9,7 +9,7 @@
         ('info', typesys.Ref('Info')),
         ('servers', typesys.Array(items=typesys.Ref('Server'))),
         ('paths', typesys.Ref('Paths')),
-        # TODO: 'components': ...,
+        ('components', typesys.Ref('Components')),
         ('security', typesys.Ref('SecurityRequirement')),
         ('tags', typesys.Array(items=typesys.Ref('Tag'))),
         ('externalDocs', typesys.Ref('ExternalDocumentation'))
@@ -86,7 +86,7 @@
                 ('externalDocs', typesys.Ref('ExternalDocumentation')),
                 ('operationId', typesys.String()),
                 ('parameters', typesys.Array(items=typesys.Ref('Parameter'))),  # TODO: Parameter | ReferenceObject
-                # TODO: 'requestBody'
+                ('requestBody', typesys.Ref('RequestBody')),  # TODO: RequestBody | ReferenceObject
                 # TODO: 'responses'
                 # TODO: 'callbacks'
                 ('deprecated', typesys.Boolean()),
@@ -109,12 +109,31 @@
                 ('required', typesys.Boolean()),
                 ('deprecated', typesys.Boolean()),
                 ('allowEmptyValue', typesys.Boolean()),
-                ('schema', JSONSchema),
+                ('schema', JSONSchema),  # TODO: | RefString
                 ('example', typesys.Any())
                 # TODO: Other fields
             ],
             required=['name', 'in']
         ),
+        'RequestBody': typesys.Object(
+            properties=[
+                ('description', typesys.String()),
+                ('content', typesys.Object(additional_properties=typesys.Ref('MediaType'))),
+                ('required', typesys.Boolean())
+            ]
+        ),
+        'MediaType': typesys.Object(
+            properties=[
+                ('schema': JSONSchema),  # TODO: | RefString
+                ('example': typesys.Any())
+                # TODO 'examples', 'encoding'
+            ]
+        ),
+        'Components': typesys.Object(
+            properties: [
+                ('schemas', typesys.Object(additional_properties=JSONSchema)),
+            ]
+        ),
         'Tag': typesys.Object(
             properties=[
                 ('name', typesys.String()),

From 69a5a6980657c9fe91c8bbc20b9b00795719814c Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 6 Mar 2018 14:25:51 +0000
Subject: [PATCH 59/60] First pass at parsing OpenAPI requestBody schemas

---
 coreapi/codecs/openapi.py     | 41 ++++++++++++++++++++++++++++-------
 coreapi/schemas/jsonschema.py | 13 ++++++-----
 coreapi/schemas/openapi.py    | 12 ++++++----
 coreapi/typesys.py            | 27 ++++++++++++++---------
 4 files changed, 65 insertions(+), 28 deletions(-)

diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
index 0d5f439..93098f9 100644
--- a/coreapi/codecs/openapi.py
+++ b/coreapi/codecs/openapi.py
@@ -1,5 +1,6 @@
+from coreapi import typesys
 from coreapi.codecs import BaseCodec, JSONSchemaCodec
-from coreapi.compat import VERBOSE_SEPARATORS, dict_type, force_bytes, urlparse
+from coreapi.compat import VERBOSE_SEPARATORS, dict_type, force_bytes, string_types, urlparse
 from coreapi.document import Document, Link, Field, Section
 from coreapi.exceptions import ParseError
 from coreapi.schemas import OpenAPI
@@ -57,10 +58,18 @@ def decode(self, bytestring, **options):
         description = lookup(openapi, ['info', 'description'])
         version = lookup(openapi, ['info', 'version'])
         base_url = lookup(openapi, ['servers', 0, 'url'])
-        sections = self.get_sections(openapi, base_url)
+        schema_definitions = self.get_schema_definitions(openapi)
+        sections = self.get_sections(openapi, base_url, schema_definitions)
         return Document(title=title, description=description, version=version, url=base_url, sections=sections)
 
-    def get_sections(self, openapi, base_url):
+    def get_schema_definitions(self, openapi):
+        definitions = {}
+        schemas = lookup(openapi, ['components', 'schemas'], {})
+        for key, value in schemas.items():
+            definitions[key] = JSONSchemaCodec().decode_from_data_structure(value)
+        return definitions
+
+    def get_sections(self, openapi, base_url, schema_definitions):
         """
         Return all the links in the document, layed out by tag and operationId.
         """
@@ -73,7 +82,7 @@ def get_sections(self, openapi, base_url):
             }
             for operation, operation_info in operations.items():
                 tag = lookup(operation_info, ['tags', 0], default='')
-                link = self.get_link(base_url, path, path_info, operation, operation_info)
+                link = self.get_link(base_url, path, path_info, operation, operation_info, schema_definitions)
                 if link is None:
                     continue
 
@@ -86,7 +95,7 @@ def get_sections(self, openapi, base_url):
             for key, value in links.items()
         ]
 
-    def get_link(self, base_url, path, path_info, operation, operation_info):
+    def get_link(self, base_url, path, path_info, operation, operation_info, schema_definitions):
         """
         Return a single link in the document.
         """
@@ -108,10 +117,22 @@ def get_link(self, base_url, path, path_info, operation, operation_info):
         parameters += operation_info.get('parameters', [])
 
         fields = [
-            self.get_field(parameter)
+            self.get_field(parameter, schema_definitions)
             for parameter in parameters
         ]
 
+        # TODO: Handle media type generically here...
+        body_schema = lookup(operation_info, ['requestBody', 'content', 'application/json', 'schema'])
+        if body_schema:
+            if isinstance(body_schema, string_types):
+                ref = body_schema[len('^#/components/schemas/'):]
+                schema = schema_definitions.get(ref)
+            else:
+                schema = JSONSchemaCodec().decode_from_data_structure(body_schema)
+            if isinstance(schema, typesys.Object):
+                for key, value in schema.properties:
+                    fields += [Field(name=key, location='form', schema=value)]
+
         return Link(
             id=id,
             url=urlparse.urljoin(base_url, path),
@@ -121,7 +142,7 @@ def get_link(self, base_url, path, path_info, operation, operation_info):
             fields=fields
         )
 
-    def get_field(self, parameter):
+    def get_field(self, parameter, schema_definitions):
         """
         Return a single field in a link.
         """
@@ -133,7 +154,11 @@ def get_field(self, parameter):
         example = parameter.get('example')
 
         if schema is not None:
-            schema = JSONSchemaCodec().decode_from_data_structure(schema)
+            if isinstance(schema, string_types):
+                ref = schema[len('^#/components/schemas/'):]
+                schema = schema_definitions.get(ref)
+            else:
+                schema = JSONSchemaCodec().decode_from_data_structure(schema)
 
         return Field(
             name=name,
diff --git a/coreapi/schemas/jsonschema.py b/coreapi/schemas/jsonschema.py
index 55535ea..d9e62c6 100644
--- a/coreapi/schemas/jsonschema.py
+++ b/coreapi/schemas/jsonschema.py
@@ -2,11 +2,12 @@
 
 
 JSONSchema = typesys.Object(
+    self_ref='JSONSchema',
     properties=[
         ('$ref', typesys.String()),
         ('type', typesys.String() | typesys.Array(items=typesys.String())),
         ('enum', typesys.Array(unique_items=True, min_items=1)),
-        ('definitions', typesys.Object(additional_properties=typesys.Ref())),
+        ('definitions', typesys.Object(additional_properties=typesys.Ref('JSONSchema'))),
 
         # String
         ('minLength', typesys.Integer(minimum=0, default=0)),
@@ -22,16 +23,16 @@
         ('multipleOf', typesys.Number(minimum=0.0, exclusive_minimum=True)),
 
         # Object
-        ('properties', typesys.Object(additional_properties=typesys.Ref())),
+        ('properties', typesys.Object(additional_properties=typesys.Ref('JSONSchema'))),
         ('minProperties', typesys.Integer(minimum=0, default=0)),
         ('maxProperties', typesys.Integer(minimum=0)),
-        ('patternProperties', typesys.Object(additional_properties=typesys.Ref())),
-        ('additionalProperties', typesys.Ref() | typesys.Boolean()),
+        ('patternProperties', typesys.Object(additional_properties=typesys.Ref('JSONSchema'))),
+        ('additionalProperties', typesys.Ref('JSONSchema') | typesys.Boolean()),
         ('required', typesys.Array(items=typesys.String(), min_items=1, unique_items=True)),
 
         # Array
-        ('items', typesys.Ref() | typesys.Array(items=typesys.Ref(), min_items=1)),
-        ('additionalItems', typesys.Ref() | typesys.Boolean()),
+        ('items', typesys.Ref('JSONSchema') | typesys.Array(items=typesys.Ref('JSONSchema'), min_items=1)),
+        ('additionalItems', typesys.Ref('JSONSchema') | typesys.Boolean()),
         ('minItems', typesys.Integer(minimum=0, default=9)),
         ('maxItems', typesys.Integer(minimum=0)),
         ('uniqueItems', typesys.Boolean()),
diff --git a/coreapi/schemas/openapi.py b/coreapi/schemas/openapi.py
index 292a888..4ff1e78 100644
--- a/coreapi/schemas/openapi.py
+++ b/coreapi/schemas/openapi.py
@@ -2,7 +2,11 @@
 from coreapi.schemas import JSONSchema
 
 
+SchemaRefString = typesys.String(pattern='^#/components/schemas/')
+
+
 OpenAPI = typesys.Object(
+    self_ref='OpenAPI',
     title='OpenAPI',
     properties=[
         ('openapi', typesys.String()),
@@ -109,7 +113,7 @@
                 ('required', typesys.Boolean()),
                 ('deprecated', typesys.Boolean()),
                 ('allowEmptyValue', typesys.Boolean()),
-                ('schema', JSONSchema),  # TODO: | RefString
+                ('schema', JSONSchema | SchemaRefString),
                 ('example', typesys.Any())
                 # TODO: Other fields
             ],
@@ -124,13 +128,13 @@
         ),
         'MediaType': typesys.Object(
             properties=[
-                ('schema': JSONSchema),  # TODO: | RefString
-                ('example': typesys.Any())
+                ('schema', JSONSchema | SchemaRefString),
+                ('example', typesys.Any())
                 # TODO 'examples', 'encoding'
             ]
         ),
         'Components': typesys.Object(
-            properties: [
+            properties=[
                 ('schemas', typesys.Object(additional_properties=JSONSchema)),
             ]
         ),
diff --git a/coreapi/typesys.py b/coreapi/typesys.py
index 2536926..b1468aa 100644
--- a/coreapi/typesys.py
+++ b/coreapi/typesys.py
@@ -37,7 +37,7 @@ def __init__(self, detail):
 class Validator(object):
     errors = {}
 
-    def __init__(self, title='', description='', default=NO_DEFAULT, definitions=None):
+    def __init__(self, title='', description='', default=NO_DEFAULT, definitions=None, self_ref=None):
         definitions = {} if (definitions is None) else dict_type(definitions)
 
         assert isinstance(title, string_types)
@@ -49,6 +49,7 @@ def __init__(self, title='', description='', default=NO_DEFAULT, definitions=Non
         self.title = title
         self.description = description
         self.definitions = definitions
+        self.self_ref = self_ref
 
         if default is not NO_DEFAULT:
             self.default = default
@@ -73,6 +74,18 @@ def error(self, code):
     def error_message(self, code):
         return self.errors[code].format(**self.__dict__)
 
+    def get_definitions(self, definitions=None):
+        if self.definitions is None and self.self_ref is None:
+            return definitions
+
+        if definitions is None:
+            definitions = {}
+        if self.definitions is not None:
+            definitions.update(self.definitions)
+        if self.self_ref is not None:
+            definitions[self.self_ref] = self
+        return definitions
+
     def __or__(self, other):
         if isinstance(self, Union):
             items = self.items
@@ -299,10 +312,6 @@ def __init__(self, properties=None, pattern_properties=None, additional_properti
         self.allow_null = allow_null
 
     def validate(self, value, definitions=None):
-        if definitions is None:
-            definitions = dict(self.definitions)
-            definitions[''] = self
-
         if value is None and self.allow_null:
             return None
         elif value is None:
@@ -310,6 +319,7 @@ def validate(self, value, definitions=None):
         elif not isinstance(value, dict):
             self.error('type')
 
+        definitions = self.get_definitions(definitions)
         validated = dict_type()
 
         # Ensure all property keys are strings.
@@ -412,10 +422,6 @@ def __init__(self, items=None, additional_items=None, min_items=None, max_items=
         self.allow_null = allow_null
 
     def validate(self, value, definitions=None):
-        if definitions is None:
-            definitions = dict(self.definitions)
-            definitions[''] = self
-
         if value is None and self.allow_null:
             return None
         elif value is None:
@@ -423,6 +429,7 @@ def validate(self, value, definitions=None):
         elif not isinstance(value, list):
             self.error('type')
 
+        definitions = self.get_definitions(definitions)
         validated = []
 
         if self.min_items is not None and self.min_items == self.max_items and len(value) != self.min_items:
@@ -500,7 +507,7 @@ def validate(self, value, definitions=None):
 
 
 class Ref(Validator):
-    def __init__(self, ref='', **kwargs):
+    def __init__(self, ref, **kwargs):
         super(Ref, self).__init__(**kwargs)
         assert isinstance(ref, string_types)
         self.ref = ref

From 3a793b97a4b1300370a5f90f87eac63e0012105e Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 6 Mar 2018 14:54:14 +0000
Subject: [PATCH 60/60] Add initial requestBody schema support

---
 coreapi/codecs/openapi.py  | 16 ++++++++++------
 coreapi/document.py        |  3 +++
 coreapi/schemas/openapi.py |  8 +++++---
 3 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/coreapi/codecs/openapi.py b/coreapi/codecs/openapi.py
index 93098f9..902190a 100644
--- a/coreapi/codecs/openapi.py
+++ b/coreapi/codecs/openapi.py
@@ -123,14 +123,17 @@ def get_link(self, base_url, path, path_info, operation, operation_info, schema_
 
         # TODO: Handle media type generically here...
         body_schema = lookup(operation_info, ['requestBody', 'content', 'application/json', 'schema'])
+
+        encoding = None
         if body_schema:
-            if isinstance(body_schema, string_types):
-                ref = body_schema[len('^#/components/schemas/'):]
+            encoding = 'application/json'
+            if '$ref' in body_schema:
+                ref = body_schema['$ref'][len('#/components/schemas/'):]
                 schema = schema_definitions.get(ref)
             else:
                 schema = JSONSchemaCodec().decode_from_data_structure(body_schema)
             if isinstance(schema, typesys.Object):
-                for key, value in schema.properties:
+                for key, value in schema.properties.items():
                     fields += [Field(name=key, location='form', schema=value)]
 
         return Link(
@@ -139,7 +142,8 @@ def get_link(self, base_url, path, path_info, operation, operation_info, schema_
             method=operation,
             title=title,
             description=description,
-            fields=fields
+            fields=fields,
+            encoding=encoding
         )
 
     def get_field(self, parameter, schema_definitions):
@@ -154,8 +158,8 @@ def get_field(self, parameter, schema_definitions):
         example = parameter.get('example')
 
         if schema is not None:
-            if isinstance(schema, string_types):
-                ref = schema[len('^#/components/schemas/'):]
+            if '$ref' in schema:
+                ref = schema['$ref'][len('#/components/schemas/'):]
                 schema = schema_definitions.get(ref)
             else:
                 schema = JSONSchemaCodec().decode_from_data_structure(schema)
diff --git a/coreapi/document.py b/coreapi/document.py
index 5128cf4..2136931 100644
--- a/coreapi/document.py
+++ b/coreapi/document.py
@@ -266,6 +266,9 @@ def path_fields(self):
     def query_fields(self):
         return [field for field in self.fields if field.location == 'query']
 
+    def form_fields(self):
+        return [field for field in self.fields if field.location == 'form']
+
     def __eq__(self, other):
         return (
             isinstance(other, Link) and
diff --git a/coreapi/schemas/openapi.py b/coreapi/schemas/openapi.py
index 4ff1e78..a395f51 100644
--- a/coreapi/schemas/openapi.py
+++ b/coreapi/schemas/openapi.py
@@ -2,7 +2,9 @@
 from coreapi.schemas import JSONSchema
 
 
-SchemaRefString = typesys.String(pattern='^#/components/schemas/')
+SchemaRef = typesys.Object(
+    properties={'$ref': typesys.String(pattern='^#/components/schemas/')}
+)
 
 
 OpenAPI = typesys.Object(
@@ -113,7 +115,7 @@
                 ('required', typesys.Boolean()),
                 ('deprecated', typesys.Boolean()),
                 ('allowEmptyValue', typesys.Boolean()),
-                ('schema', JSONSchema | SchemaRefString),
+                ('schema', JSONSchema | SchemaRef),
                 ('example', typesys.Any())
                 # TODO: Other fields
             ],
@@ -128,7 +130,7 @@
         ),
         'MediaType': typesys.Object(
             properties=[
-                ('schema', JSONSchema | SchemaRefString),
+                ('schema', JSONSchema | SchemaRef),
                 ('example', typesys.Any())
                 # TODO 'examples', 'encoding'
             ]