Merge pull request #2497 from pkch/firstresult

Docs: clarify when hooks stop after the first non-None result

Author: RonnyPfannschmidt

_pytest/hookspec.py

@@ -73,15 +73,19 @@ def pytest_configure(config):
 
 @hookspec(firstresult=True)
 def pytest_cmdline_parse(pluginmanager, args):
-    """return initialized config object, parsing the specified args. """
+    """return initialized config object, parsing the specified args.
+
+    Stops at first non-None result, see :ref:`firstresult` """
 
 def pytest_cmdline_preparse(config, args):
     """(deprecated) modify command line arguments before option parsing. """
 
 @hookspec(firstresult=True)
 def pytest_cmdline_main(config):
     """ called for performing the main command line action. The default
-    implementation will invoke the configure hooks and runtest_mainloop. """
+    implementation will invoke the configure hooks and runtest_mainloop.
+
+    Stops at first non-None result, see :ref:`firstresult` """
 
 def pytest_load_initial_conftests(early_config, parser, args):
     """ implements the loading of initial conftest files ahead
@@ -94,7 +98,9 @@ def pytest_load_initial_conftests(early_config, parser, args):
 
 @hookspec(firstresult=True)
 def pytest_collection(session):
-    """ perform the collection protocol for the given session. """
+    """ perform the collection protocol for the given session.
+
+    Stops at first non-None result, see :ref:`firstresult` """
 
 def pytest_collection_modifyitems(session, config, items):
     """ called after collection has been performed, may filter or re-order
@@ -108,11 +114,15 @@ def pytest_ignore_collect(path, config):
     """ return True to prevent considering this path for collection.
     This hook is consulted for all files and directories prior to calling
     more specific hooks.
+
+    Stops at first non-None result, see :ref:`firstresult`
     """
 
 @hookspec(firstresult=True)
 def pytest_collect_directory(path, parent):
-    """ called before traversing a directory for collection files. """
+    """ called before traversing a directory for collection files.
+
+    Stops at first non-None result, see :ref:`firstresult` """
 
 def pytest_collect_file(path, parent):
     """ return collection Node or None for the given path. Any new node
@@ -133,7 +143,9 @@ def pytest_deselected(items):
 
 @hookspec(firstresult=True)
 def pytest_make_collect_report(collector):
-    """ perform ``collector.collect()`` and return a CollectReport. """
+    """ perform ``collector.collect()`` and return a CollectReport.
+
+    Stops at first non-None result, see :ref:`firstresult` """
 
 # -------------------------------------------------------------------------
 # Python test function related hooks
@@ -145,15 +157,20 @@ def pytest_pycollect_makemodule(path, parent):
     This hook will be called for each matching test module path.
     The pytest_collect_file hook needs to be used if you want to
     create test modules for files that do not match as a test module.
-    """
+
+    Stops at first non-None result, see :ref:`firstresult` """
 
 @hookspec(firstresult=True)
 def pytest_pycollect_makeitem(collector, name, obj):
-    """ return custom item/collector for a python object in a module, or None.  """
+    """ return custom item/collector for a python object in a module, or None.
+
+    Stops at first non-None result, see :ref:`firstresult` """
 
 @hookspec(firstresult=True)
 def pytest_pyfunc_call(pyfuncitem):
-    """ call underlying test function. """
+    """ call underlying test function.
+
+    Stops at first non-None result, see :ref:`firstresult` """
 
 def pytest_generate_tests(metafunc):
     """ generate (multiple) parametrized calls to a test function."""
@@ -163,7 +180,8 @@ def pytest_make_parametrize_id(config, val, argname):
     """Return a user-friendly string representation of the given ``val`` that will be used
     by @pytest.mark.parametrize calls. Return None if the hook doesn't know about ``val``.
     The parameter name is available as ``argname``, if required.
-    """
+
+    Stops at first non-None result, see :ref:`firstresult` """
 
 # -------------------------------------------------------------------------
 # generic runtest related hooks
@@ -172,7 +190,9 @@ def pytest_make_parametrize_id(config, val, argname):
 @hookspec(firstresult=True)
 def pytest_runtestloop(session):
     """ called for performing the main runtest loop
-    (after collection finished). """
+    (after collection finished).
+
+    Stops at first non-None result, see :ref:`firstresult` """
 
 def pytest_itemstart(item, node):
     """ (deprecated, use pytest_runtest_logstart). """
@@ -190,7 +210,9 @@ def pytest_runtest_protocol(item, nextitem):
                    :py:func:`pytest_runtest_teardown`.
 
     :return boolean: True if no further hook implementations should be invoked.
-    """
+
+
+    Stops at first non-None result, see :ref:`firstresult` """
 
 def pytest_runtest_logstart(nodeid, location):
     """ signal the start of running a single test item. """
@@ -215,7 +237,8 @@ def pytest_runtest_makereport(item, call):
     """ return a :py:class:`_pytest.runner.TestReport` object
     for the given :py:class:`pytest.Item <_pytest.main.Item>` and
     :py:class:`_pytest.runner.CallInfo`.
-    """
+
+    Stops at first non-None result, see :ref:`firstresult` """
 
 def pytest_runtest_logreport(report):
     """ process a test setup/call/teardown report relating to
@@ -227,7 +250,9 @@ def pytest_runtest_logreport(report):
 
 @hookspec(firstresult=True)
 def pytest_fixture_setup(fixturedef, request):
-    """ performs fixture setup execution. """
+    """ performs fixture setup execution.
+
+    Stops at first non-None result, see :ref:`firstresult` """
 
 def pytest_fixture_post_finalizer(fixturedef):
     """ called after fixture teardown, but before the cache is cleared so
@@ -277,7 +302,9 @@ def pytest_report_header(config, startdir):
 
 @hookspec(firstresult=True)
 def pytest_report_teststatus(report):
-    """ return result-category, shortletter and verbose word for reporting."""
+    """ return result-category, shortletter and verbose word for reporting.
+
+    Stops at first non-None result, see :ref:`firstresult` """
 
 def pytest_terminal_summary(terminalreporter, exitstatus):
     """ add additional section in terminal summary reporting.  """
@@ -295,7 +322,9 @@ def pytest_logwarning(message, code, nodeid, fslocation):
 
 @hookspec(firstresult=True)
 def pytest_doctest_prepare_content(content):
-    """ return processed content for a given doctest"""
+    """ return processed content for a given doctest
+
+    Stops at first non-None result, see :ref:`firstresult` """
 
 # -------------------------------------------------------------------------
 # error handling and internal debugging hooks

changelog/2493.doc

@@ -0,0 +1 @@
+Explicitly state for which hooks the calls stop after the first non-None result.

doc/en/writing_plugins.rst

@@ -255,11 +255,11 @@ if ``myapp.testsupport.myplugin`` also declares ``pytest_plugins``, the contents
 of the variable will also be loaded as plugins, and so on.
 
 This mechanism makes it easy to share fixtures within applications or even
-external applications without the need to create external plugins using 
+external applications without the need to create external plugins using
 the ``setuptools``'s entry point technique.
 
 Plugins imported by ``pytest_plugins`` will also automatically be marked
-for assertion rewriting (see :func:`pytest.register_assert_rewrite`). 
+for assertion rewriting (see :func:`pytest.register_assert_rewrite`).
 However for this to have any effect the module must not be
 imported already; if it was already imported at the time the
 ``pytest_plugins`` statement is processed, a warning will result and
@@ -357,6 +357,8 @@ allowed to raise exceptions.  Doing so will break the pytest run.
 
 
 
+.. _firstresult:
+
 firstresult: stop at first non-None result
 -------------------------------------------