[wip] detangle Config init

_pytest/config/argument_parsing.py

@@ -0,0 +1,383 @@
+"""
+"""
+import warnings
+import six
+import argparse
+
+FILE_OR_DIR = 'file_or_dir'
+
+
+class Parser(object):
+    """ Parser for command line arguments and ini-file values.
+
+    :ivar extra_info: dict of generic param -> value to display in case
+        there's an error processing the command line arguments.
+    """
+
+    def __init__(self, usage=None, processopt=None):
+        self._anonymous = OptionGroup("custom options", parser=self)
+        self._groups = []
+        self._processopt = processopt
+        self._usage = usage
+        self._inidict = {}
+        self._ininames = []
+        self.extra_info = {}
+
+    def processoption(self, option):
+        if self._processopt:
+            if option.dest:
+                self._processopt(option)
+
+    def getgroup(self, name, description="", after=None):
+        """ get (or create) a named option Group.
+
+        :name: name of the option group.
+        :description: long description for --help output.
+        :after: name of other group, used for ordering --help output.
+
+        The returned group object has an ``addoption`` method with the same
+        signature as :py:func:`parser.addoption
+        <_pytest.config.Parser.addoption>` but will be shown in the
+        respective group in the output of ``pytest. --help``.
+        """
+        for group in self._groups:
+            if group.name == name:
+                return group
+        group = OptionGroup(name, description, parser=self)
+        i = 0
+        for i, grp in enumerate(self._groups):
+            if grp.name == after:
+                break
+        self._groups.insert(i + 1, group)
+        return group
+
+    def addoption(self, *opts, **attrs):
+        """ register a command line option.
+
+        :opts: option names, can be short or long options.
+        :attrs: same attributes which the ``add_option()`` function of the
+           `argparse library
+           <http://docs.python.org/2/library/argparse.html>`_
+           accepts.
+
+        After command line parsing options are available on the pytest config
+        object via ``config.option.NAME`` where ``NAME`` is usually set
+        by passing a ``dest`` attribute, for example
+        ``addoption("--long", dest="NAME", ...)``.
+        """
+        self._anonymous.addoption(*opts, **attrs)
+
+    def parse(self, args, namespace=None):
+        from _pytest._argcomplete import try_argcomplete
+        self.optparser = self._getparser()
+        try_argcomplete(self.optparser)
+        return self.optparser.parse_args([str(x) for x in args], namespace=namespace)
+
+    def _getparser(self):
+        from _pytest._argcomplete import filescompleter
+        optparser = MyOptionParser(self, self.extra_info)
+        groups = self._groups + [self._anonymous]
+        for group in groups:
+            if group.options:
+                desc = group.description or group.name
+                arggroup = optparser.add_argument_group(desc)
+                for option in group.options:
+                    n = option.names()
+                    a = option.attrs()
+                    arggroup.add_argument(*n, **a)
+        # bash like autocompletion for dirs (appending '/')
+        optparser.add_argument(FILE_OR_DIR, nargs='*').completer = filescompleter
+        return optparser
+
+    def parse_setoption(self, args, option, namespace=None):
+        parsedoption = self.parse(args, namespace=namespace)
+        for name, value in parsedoption.__dict__.items():
+            setattr(option, name, value)
+        return getattr(parsedoption, FILE_OR_DIR)
+
+    def parse_known_args(self, args, namespace=None):
+        """parses and returns a namespace object with known arguments at this
+        point.
+        """
+        return self.parse_known_and_unknown_args(args, namespace=namespace)[0]
+
+    def parse_known_and_unknown_args(self, args, namespace=None):
+        """parses and returns a namespace object with known arguments, and
+        the remaining arguments unknown at this point.
+        """
+        optparser = self._getparser()
+        args = [str(x) for x in args]
+        return optparser.parse_known_args(args, namespace=namespace)
+
+    def addini(self, name, help, type=None, default=None):
+        """ register an ini-file option.
+
+        :name: name of the ini-variable
+        :type: type of the variable, can be ``pathlist``, ``args``, ``linelist``
+               or ``bool``.
+        :default: default value if no ini-file option exists but is queried.
+
+        The value of ini-variables can be retrieved via a call to
+        :py:func:`config.getini(name) <_pytest.config.Config.getini>`.
+        """
+        assert type in (None, "pathlist", "args", "linelist", "bool")
+        self._inidict[name] = (help, type, default)
+        self._ininames.append(name)
+
+
+class ArgumentError(Exception):
+    """
+    Raised if an Argument instance is created with invalid or
+    inconsistent arguments.
+    """
+
+    def __init__(self, msg, option):
+        self.msg = msg
+        self.option_id = str(option)
+
+    def __str__(self):
+        if self.option_id:
+            return "option %s: %s" % (self.option_id, self.msg)
+        else:
+            return self.msg
+
+
+class Argument(object):
+    """class that mimics the necessary behaviour of optparse.Option
+
+    its currently a least effort implementation
+    and ignoring choices and integer prefixes
+    https://docs.python.org/3/library/optparse.html#optparse-standard-option-types
+    """
+    _typ_map = {
+        'int': int,
+        'string': str,
+        'float': float,
+        'complex': complex,
+    }
+
+    def __init__(self, *names, **attrs):
+        """store parms in private vars for use in add_argument"""
+        self._attrs = attrs
+        self._short_opts = []
+        self._long_opts = []
+        self.dest = attrs.get('dest')
+        if '%default' in (attrs.get('help') or ''):
+            warnings.warn(
+                'pytest now uses argparse. "%default" should be'
+                ' changed to "%(default)s" ',
+                DeprecationWarning,
+                stacklevel=3)
+        try:
+            typ = attrs['type']
+        except KeyError:
+            pass
+        else:
+            # this might raise a keyerror as well, don't want to catch that
+            if isinstance(typ, six.string_types):
+                if typ == 'choice':
+                    warnings.warn(
+                        'type argument to addoption() is a string %r.'
+                        ' For parsearg this is optional and when supplied'
+                        ' should be a type.'
+                        ' (options: %s)' % (typ, names),
+                        DeprecationWarning,
+                        stacklevel=3)
+                    # argparse expects a type here take it from
+                    # the type of the first element
+                    attrs['type'] = type(attrs['choices'][0])
+                else:
+                    warnings.warn(
+                        'type argument to addoption() is a string %r.'
+                        ' For parsearg this should be a type.'
+                        ' (options: %s)' % (typ, names),
+                        DeprecationWarning,
+                        stacklevel=3)
+                    attrs['type'] = Argument._typ_map[typ]
+                # used in test_parseopt -> test_parse_defaultgetter
+                self.type = attrs['type']
+            else:
+                self.type = typ
+        try:
+            # attribute existence is tested in Config._processopt
+            self.default = attrs['default']
+        except KeyError:
+            pass
+        self._set_opt_strings(names)
+        if not self.dest:
+            if self._long_opts:
+                self.dest = self._long_opts[0][2:].replace('-', '_')
+            else:
+                try:
+                    self.dest = self._short_opts[0][1:]
+                except IndexError:
+                    raise ArgumentError(
+                        'need a long or short option', self)
+
+    def names(self):
+        return self._short_opts + self._long_opts
+
+    def attrs(self):
+        # update any attributes set by processopt
+        attrs = 'default dest help'.split()
+        if self.dest:
+            attrs.append(self.dest)
+        for attr in attrs:
+            try:
+                self._attrs[attr] = getattr(self, attr)
+            except AttributeError:
+                pass
+        if self._attrs.get('help'):
+            a = self._attrs['help']
+            a = a.replace('%default', '%(default)s')
+            # a = a.replace('%prog', '%(prog)s')
+            self._attrs['help'] = a
+        return self._attrs
+
+    def _set_opt_strings(self, opts):
+        """directly from optparse
+
+        might not be necessary as this is passed to argparse later on"""
+        for opt in opts:
+            if len(opt) < 2:
+                raise ArgumentError(
+                    "invalid option string %r: "
+                    "must be at least two characters long" % opt, self)
+            elif len(opt) == 2:
+                if not (opt[0] == "-" and opt[1] != "-"):
+                    raise ArgumentError(
+                        "invalid short option string %r: "
+                        "must be of the form -x, (x any non-dash char)" % opt,
+                        self)
+                self._short_opts.append(opt)
+            else:
+                if not (opt[0:2] == "--" and opt[2] != "-"):
+                    raise ArgumentError(
+                        "invalid long option string %r: "
+                        "must start with --, followed by non-dash" % opt,
+                        self)
+                self._long_opts.append(opt)
+
+    def __repr__(self):
+        args = []
+        if self._short_opts:
+            args += ['_short_opts: ' + repr(self._short_opts)]
+        if self._long_opts:
+            args += ['_long_opts: ' + repr(self._long_opts)]
+        args += ['dest: ' + repr(self.dest)]
+        if hasattr(self, 'type'):
+            args += ['type: ' + repr(self.type)]
+        if hasattr(self, 'default'):
+            args += ['default: ' + repr(self.default)]
+        return 'Argument({0})'.format(', '.join(args))
+
+
+class OptionGroup(object):
+    def __init__(self, name, description="", parser=None):
+        self.name = name
+        self.description = description
+        self.options = []
+        self.parser = parser
+
+    def addoption(self, *optnames, **attrs):
+        """ add an option to this group.
+
+        if a shortened version of a long option is specified it will
+        be suppressed in the help. addoption('--twowords', '--two-words')
+        results in help showing '--two-words' only, but --twowords gets
+        accepted **and** the automatic destination is in args.twowords
+        """
+        conflict = set(optnames).intersection(
+            name for opt in self.options for name in opt.names())
+        if conflict:
+            raise ValueError("option names %s already added" % conflict)
+        option = Argument(*optnames, **attrs)
+        self._addoption_instance(option, shortupper=False)
+
+    def _addoption(self, *optnames, **attrs):
+        option = Argument(*optnames, **attrs)
+        self._addoption_instance(option, shortupper=True)
+
+    def _addoption_instance(self, option, shortupper=False):
+        if not shortupper:
+            for opt in option._short_opts:
+                if opt[0] == '-' and opt[1].islower():
+                    raise ValueError("lowercase shortoptions reserved")
+        if self.parser:
+            self.parser.processoption(option)
+        self.options.append(option)
+
+
+class MyOptionParser(argparse.ArgumentParser):
+    def __init__(self, parser, extra_info=None):
+        if not extra_info:
+            extra_info = {}
+        self._parser = parser
+        argparse.ArgumentParser.__init__(self, usage=parser._usage,
+                                         add_help=False, formatter_class=DropShorterLongHelpFormatter)
+        # extra_info is a dict of (param -> value) to display if there's
+        # an usage error to provide more contextual information to the user
+        self.extra_info = extra_info
+
+    def parse_args(self, args=None, namespace=None):
+        """allow splitting of positional arguments"""
+        args, argv = self.parse_known_args(args, namespace)
+        if argv:
+            for arg in argv:
+                if arg and arg[0] == '-':
+                    lines = ['unrecognized arguments: %s' % (' '.join(argv))]
+                    for k, v in sorted(self.extra_info.items()):
+                        lines.append('  %s: %s' % (k, v))
+                    self.error('\n'.join(lines))
+            getattr(args, FILE_OR_DIR).extend(argv)
+        return args
+
+
+class DropShorterLongHelpFormatter(argparse.HelpFormatter):
+    """shorten help for long options that differ only in extra hyphens
+
+    - collapse **long** options that are the same except for extra hyphens
+    - special action attribute map_long_option allows surpressing additional
+      long options
+    - shortcut if there are only two options and one of them is a short one
+    - cache result on action object as this is called at least 2 times
+    """
+
+    def _format_action_invocation(self, action):
+        orgstr = argparse.HelpFormatter._format_action_invocation(self, action)
+        if orgstr and orgstr[0] != '-':  # only optional arguments
+            return orgstr
+        res = getattr(action, '_formatted_action_invocation', None)
+        if res:
+            return res
+        options = orgstr.split(', ')
+        if len(options) == 2 and (len(options[0]) == 2 or len(options[1]) == 2):
+            # a shortcut for '-h, --help' or '--abc', '-a'
+            action._formatted_action_invocation = orgstr
+            return orgstr
+        return_list = []
+        option_map = getattr(action, 'map_long_option', {})
+        if option_map is None:
+            option_map = {}
+        short_long = {}
+        for option in options:
+            if len(option) == 2 or option[2] == ' ':
+                continue
+            if not option.startswith('--'):
+                raise ArgumentError('long optional argument without "--": [%s]'
+                                    % (option), self)
+            xxoption = option[2:]
+            if xxoption.split()[0] not in option_map:
+                shortened = xxoption.replace('-', '')
+                if shortened not in short_long or \
+                   len(short_long[shortened]) < len(xxoption):
+                    short_long[shortened] = xxoption
+        # now short_long has been filled out to the longest with dashes
+        # **and** we keep the right option ordering from add_argument
+        for option in options:
+            if len(option) == 2 or option[2] == ' ':
+                return_list.append(option)
+            if option[2:] == short_long.get(option.replace('-', '')):
+                return_list.append(option.replace(' ', '=', 1))
+        action._formatted_action_invocation = ', '.join(return_list)
+        return action._formatted_action_invocation