Merge pull request #3535 from RonnyPfannschmidt/config-split

begin to turn config into package

doc/en/reference.rst

@@ -733,7 +733,7 @@ Node
 Parser
 ~~~~~~
 
-.. autoclass:: _pytest.config.Parser()
+.. autoclass:: _pytest.config.argparsing.Parser()
     :members:
 
 PluginManager

setup.py

@@ -108,7 +108,13 @@ def main():
         python_requires=">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*",
         install_requires=install_requires,
         extras_require=extras_require,
-        packages=["_pytest", "_pytest.assertion", "_pytest._code", "_pytest.mark"],
+        packages=[
+            "_pytest",
+            "_pytest.assertion",
+            "_pytest._code",
+            "_pytest.mark",
+            "_pytest.config",
+        ],
         py_modules=["pytest"],
         zip_safe=False,
     )

src/_pytest/config/__init__.py

@@ -19,6 +19,8 @@ import _pytest.hookspec  # the extension point definitions
 import _pytest.assertion
 from pluggy import PluginManager, HookimplMarker, HookspecMarker
 from _pytest.compat import safe_str
+from .exceptions import UsageError, PrintHelp
+from .findpaths import determine_setup, exists
 
 hookimpl = HookimplMarker("pytest")
 hookspec = HookspecMarker("pytest")
@@ -74,16 +76,6 @@ class cmdline(object):  # NOQA compatibility namespace
     main = staticmethod(main)
 
 
-class UsageError(Exception):
-    """ error in pytest usage or invocation"""
-
-
-class PrintHelp(Exception):
-    """Raised when pytest should print it's help to skip the rest of the
-    argument parsing and validation."""
-    pass
-
-
 def filename_arg(path, optname):
     """ Argparse type validator for filename arguments.
 
@@ -107,11 +99,33 @@ def directory_arg(path, optname):
 
 
 default_plugins = (
-    "mark main terminal runner python fixtures debugging unittest capture skipping "
+    "mark",
-    "tmpdir monkeypatch recwarn pastebin helpconfig nose assertion "
+    "main",
-    "junitxml resultlog doctest cacheprovider freeze_support "
+    "terminal",
-    "setuponly setupplan warnings logging"
+    "runner",
-).split()
+    "python",
+    "fixtures",
+    "debugging",
+    "unittest",
+    "capture",
+    "skipping",
+    "tmpdir",
+    "monkeypatch",
+    "recwarn",
+    "pastebin",
+    "helpconfig",
+    "nose",
+    "assertion",
+    "junitxml",
+    "resultlog",
+    "doctest",
+    "cacheprovider",
+    "freeze_support",
+    "setuponly",
+    "setupplan",
+    "warnings",
+    "logging",
+)
 
 
 builtin_plugins = set(default_plugins)
@@ -496,395 +510,6 @@ def _get_plugin_specs_as_list(specs):
     return []
 
 
-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({})".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
-
-
 def _ensure_removed_sysmodule(modname):
     try:
         del sys.modules[modname]
@@ -899,7 +524,6 @@ class Notset(object):
 
 
 notset = Notset()
-FILE_OR_DIR = "file_or_dir"
 
 
 def _iter_rewritable_modules(package_files):
@@ -921,6 +545,8 @@ class Config(object):
         #: access to command line option as attributes.
         #: (deprecated), use :py:func:`getoption() <_pytest.config.Config.getoption>` instead
         self.option = argparse.Namespace()
+        from .argparsing import Parser, FILE_OR_DIR
+
         _a = FILE_OR_DIR
         self._parser = Parser(
             usage="%%(prog)s [options] [%s] [%s] [...]" % (_a, _a),
@@ -1300,143 +926,6 @@ def _warn_about_missing_assertion(mode):
             )
 
 
-def exists(path, ignore=EnvironmentError):
-    try:
-        return path.check()
-    except ignore:
-        return False
-
-
-def getcfg(args, warnfunc=None):
-    """
-    Search the list of arguments for a valid ini-file for pytest,
-    and return a tuple of (rootdir, inifile, cfg-dict).
-
-    note: warnfunc is an optional function used to warn
-        about ini-files that use deprecated features.
-        This parameter should be removed when pytest
-        adopts standard deprecation warnings (#1804).
-    """
-    from _pytest.deprecated import CFG_PYTEST_SECTION
-
-    inibasenames = ["pytest.ini", "tox.ini", "setup.cfg"]
-    args = [x for x in args if not str(x).startswith("-")]
-    if not args:
-        args = [py.path.local()]
-    for arg in args:
-        arg = py.path.local(arg)
-        for base in arg.parts(reverse=True):
-            for inibasename in inibasenames:
-                p = base.join(inibasename)
-                if exists(p):
-                    iniconfig = py.iniconfig.IniConfig(p)
-                    if "pytest" in iniconfig.sections:
-                        if inibasename == "setup.cfg" and warnfunc:
-                            warnfunc(
-                                "C1", CFG_PYTEST_SECTION.format(filename=inibasename)
-                            )
-                        return base, p, iniconfig["pytest"]
-                    if (
-                        inibasename == "setup.cfg"
-                        and "tool:pytest" in iniconfig.sections
-                    ):
-                        return base, p, iniconfig["tool:pytest"]
-                    elif inibasename == "pytest.ini":
-                        # allowed to be empty
-                        return base, p, {}
-    return None, None, None
-
-
-def get_common_ancestor(paths):
-    common_ancestor = None
-    for path in paths:
-        if not path.exists():
-            continue
-        if common_ancestor is None:
-            common_ancestor = path
-        else:
-            if path.relto(common_ancestor) or path == common_ancestor:
-                continue
-            elif common_ancestor.relto(path):
-                common_ancestor = path
-            else:
-                shared = path.common(common_ancestor)
-                if shared is not None:
-                    common_ancestor = shared
-    if common_ancestor is None:
-        common_ancestor = py.path.local()
-    elif common_ancestor.isfile():
-        common_ancestor = common_ancestor.dirpath()
-    return common_ancestor
-
-
-def get_dirs_from_args(args):
-
-    def is_option(x):
-        return str(x).startswith("-")
-
-    def get_file_part_from_node_id(x):
-        return str(x).split("::")[0]
-
-    def get_dir_from_path(path):
-        if path.isdir():
-            return path
-        return py.path.local(path.dirname)
-
-    # These look like paths but may not exist
-    possible_paths = (
-        py.path.local(get_file_part_from_node_id(arg))
-        for arg in args
-        if not is_option(arg)
-    )
-
-    return [get_dir_from_path(path) for path in possible_paths if path.exists()]
-
-
-def determine_setup(inifile, args, warnfunc=None, rootdir_cmd_arg=None):
-    dirs = get_dirs_from_args(args)
-    if inifile:
-        iniconfig = py.iniconfig.IniConfig(inifile)
-        is_cfg_file = str(inifile).endswith(".cfg")
-        # TODO: [pytest] section in *.cfg files is depricated. Need refactoring.
-        sections = ["tool:pytest", "pytest"] if is_cfg_file else ["pytest"]
-        for section in sections:
-            try:
-                inicfg = iniconfig[section]
-                if is_cfg_file and section == "pytest" and warnfunc:
-                    from _pytest.deprecated import CFG_PYTEST_SECTION
-
-                    warnfunc("C1", CFG_PYTEST_SECTION.format(filename=str(inifile)))
-                break
-            except KeyError:
-                inicfg = None
-        rootdir = get_common_ancestor(dirs)
-    else:
-        ancestor = get_common_ancestor(dirs)
-        rootdir, inifile, inicfg = getcfg([ancestor], warnfunc=warnfunc)
-        if rootdir is None:
-            for rootdir in ancestor.parts(reverse=True):
-                if rootdir.join("setup.py").exists():
-                    break
-            else:
-                rootdir, inifile, inicfg = getcfg(dirs, warnfunc=warnfunc)
-                if rootdir is None:
-                    rootdir = get_common_ancestor([py.path.local(), ancestor])
-                    is_fs_root = os.path.splitdrive(str(rootdir))[1] == "/"
-                    if is_fs_root:
-                        rootdir = ancestor
-    if rootdir_cmd_arg:
-        rootdir_abs_path = py.path.local(os.path.expandvars(rootdir_cmd_arg))
-        if not os.path.isdir(str(rootdir_abs_path)):
-            raise UsageError(
-                "Directory '{}' not found. Check your '--rootdir' option.".format(
-                    rootdir_abs_path
-                )
-            )
-        rootdir = rootdir_abs_path
-    return rootdir, inifile, inicfg or {}
-
-
 def setns(obj, dic):
     import pytest
 

src/_pytest/config/argparsing.py

@@ -0,0 +1,394 @@
+import six
+import warnings
+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({})".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

src/_pytest/config/exceptions.py

@@ -0,0 +1,8 @@
+class UsageError(Exception):
+    """ error in pytest usage or invocation"""
+
+
+class PrintHelp(Exception):
+    """Raised when pytest should print it's help to skip the rest of the
+    argument parsing and validation."""
+    pass

src/_pytest/config/findpaths.py

@@ -0,0 +1,140 @@
+import py
+import os
+from .exceptions import UsageError
+
+
+def exists(path, ignore=EnvironmentError):
+    try:
+        return path.check()
+    except ignore:
+        return False
+
+
+def getcfg(args, warnfunc=None):
+    """
+    Search the list of arguments for a valid ini-file for pytest,
+    and return a tuple of (rootdir, inifile, cfg-dict).
+
+    note: warnfunc is an optional function used to warn
+        about ini-files that use deprecated features.
+        This parameter should be removed when pytest
+        adopts standard deprecation warnings (#1804).
+    """
+    from _pytest.deprecated import CFG_PYTEST_SECTION
+
+    inibasenames = ["pytest.ini", "tox.ini", "setup.cfg"]
+    args = [x for x in args if not str(x).startswith("-")]
+    if not args:
+        args = [py.path.local()]
+    for arg in args:
+        arg = py.path.local(arg)
+        for base in arg.parts(reverse=True):
+            for inibasename in inibasenames:
+                p = base.join(inibasename)
+                if exists(p):
+                    iniconfig = py.iniconfig.IniConfig(p)
+                    if "pytest" in iniconfig.sections:
+                        if inibasename == "setup.cfg" and warnfunc:
+                            warnfunc(
+                                "C1", CFG_PYTEST_SECTION.format(filename=inibasename)
+                            )
+                        return base, p, iniconfig["pytest"]
+                    if (
+                        inibasename == "setup.cfg"
+                        and "tool:pytest" in iniconfig.sections
+                    ):
+                        return base, p, iniconfig["tool:pytest"]
+                    elif inibasename == "pytest.ini":
+                        # allowed to be empty
+                        return base, p, {}
+    return None, None, None
+
+
+def get_common_ancestor(paths):
+    common_ancestor = None
+    for path in paths:
+        if not path.exists():
+            continue
+        if common_ancestor is None:
+            common_ancestor = path
+        else:
+            if path.relto(common_ancestor) or path == common_ancestor:
+                continue
+            elif common_ancestor.relto(path):
+                common_ancestor = path
+            else:
+                shared = path.common(common_ancestor)
+                if shared is not None:
+                    common_ancestor = shared
+    if common_ancestor is None:
+        common_ancestor = py.path.local()
+    elif common_ancestor.isfile():
+        common_ancestor = common_ancestor.dirpath()
+    return common_ancestor
+
+
+def get_dirs_from_args(args):
+
+    def is_option(x):
+        return str(x).startswith("-")
+
+    def get_file_part_from_node_id(x):
+        return str(x).split("::")[0]
+
+    def get_dir_from_path(path):
+        if path.isdir():
+            return path
+        return py.path.local(path.dirname)
+
+    # These look like paths but may not exist
+    possible_paths = (
+        py.path.local(get_file_part_from_node_id(arg))
+        for arg in args
+        if not is_option(arg)
+    )
+
+    return [get_dir_from_path(path) for path in possible_paths if path.exists()]
+
+
+def determine_setup(inifile, args, warnfunc=None, rootdir_cmd_arg=None):
+    dirs = get_dirs_from_args(args)
+    if inifile:
+        iniconfig = py.iniconfig.IniConfig(inifile)
+        is_cfg_file = str(inifile).endswith(".cfg")
+        # TODO: [pytest] section in *.cfg files is depricated. Need refactoring.
+        sections = ["tool:pytest", "pytest"] if is_cfg_file else ["pytest"]
+        for section in sections:
+            try:
+                inicfg = iniconfig[section]
+                if is_cfg_file and section == "pytest" and warnfunc:
+                    from _pytest.deprecated import CFG_PYTEST_SECTION
+
+                    warnfunc("C1", CFG_PYTEST_SECTION.format(filename=str(inifile)))
+                break
+            except KeyError:
+                inicfg = None
+        rootdir = get_common_ancestor(dirs)
+    else:
+        ancestor = get_common_ancestor(dirs)
+        rootdir, inifile, inicfg = getcfg([ancestor], warnfunc=warnfunc)
+        if rootdir is None:
+            for rootdir in ancestor.parts(reverse=True):
+                if rootdir.join("setup.py").exists():
+                    break
+            else:
+                rootdir, inifile, inicfg = getcfg(dirs, warnfunc=warnfunc)
+                if rootdir is None:
+                    rootdir = get_common_ancestor([py.path.local(), ancestor])
+                    is_fs_root = os.path.splitdrive(str(rootdir))[1] == "/"
+                    if is_fs_root:
+                        rootdir = ancestor
+    if rootdir_cmd_arg:
+        rootdir_abs_path = py.path.local(os.path.expandvars(rootdir_cmd_arg))
+        if not os.path.isdir(str(rootdir_abs_path)):
+            raise UsageError(
+                "Directory '{}' not found. Check your '--rootdir' option.".format(
+                    rootdir_abs_path
+                )
+            )
+        rootdir = rootdir_abs_path
+    return rootdir, inifile, inicfg or {}

testing/test_capture.py

@@ -51,7 +51,7 @@ class TestCaptureManager(object):
 
     def test_getmethod_default_no_fd(self, monkeypatch):
         from _pytest.capture import pytest_addoption
-        from _pytest.config import Parser
+        from _pytest.config.argparsing import Parser
 
         parser = Parser()
         pytest_addoption(parser)

testing/test_config.py

@@ -4,12 +4,8 @@ import textwrap
 import pytest
 
 import _pytest._code
-from _pytest.config import (
+from _pytest.config.findpaths import getcfg, get_common_ancestor, determine_setup
-    getcfg,
+from _pytest.config import _iter_rewritable_modules
-    get_common_ancestor,
-    determine_setup,
-    _iter_rewritable_modules,
-)
 from _pytest.main import EXIT_NOTESTSCOLLECTED
 
 

testing/test_parseopt.py

@@ -4,7 +4,7 @@ import sys
 import os
 import py
 import pytest
-from _pytest import config as parseopt
+from _pytest.config import argparsing as parseopt
 
 
 @pytest.fixture