__init__.py

""" command line options, ini-file and conftest.py processing. """
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import argparse
import copy
import inspect
import os
import shlex
import sys
import types
import warnings
from distutils.version import LooseVersion

import py
import six
from pluggy import HookimplMarker
from pluggy import HookspecMarker
from pluggy import PluginManager

import _pytest._code
import _pytest.assertion
import _pytest.hookspec  # the extension point definitions
from .exceptions import PrintHelp
from .exceptions import UsageError
from .findpaths import determine_setup
from .findpaths import exists
from _pytest._code import ExceptionInfo
from _pytest._code import filter_traceback
from _pytest.compat import lru_cache
from _pytest.compat import safe_str
from _pytest.outcomes import Skipped

hookimpl = HookimplMarker("pytest")
hookspec = HookspecMarker("pytest")


class ConftestImportFailure(Exception):
    def __init__(self, path, excinfo):
        Exception.__init__(self, path, excinfo)
        self.path = path
        self.excinfo = excinfo


def main(args=None, plugins=None):
    """ return exit code, after performing an in-process test run.

    :arg args: list of command line arguments.

    :arg plugins: list of plugin objects to be auto-registered during
                  initialization.
    """
    from _pytest.main import EXIT_USAGEERROR

    try:
        try:
            config = _prepareconfig(args, plugins)
        except ConftestImportFailure as e:
            exc_info = ExceptionInfo(e.excinfo)
            tw = py.io.TerminalWriter(sys.stderr)
            tw.line(
                "ImportError while loading conftest '{e.path}'.".format(e=e), red=True
            )
            exc_info.traceback = exc_info.traceback.filter(filter_traceback)
            exc_repr = (
                exc_info.getrepr(style="short", chain=False)
                if exc_info.traceback
                else exc_info.exconly()
            )
            formatted_tb = safe_str(exc_repr)
            for line in formatted_tb.splitlines():
                tw.line(line.rstrip(), red=True)
            return 4
        else:
            try:
                return config.hook.pytest_cmdline_main(config=config)
            finally:
                config._ensure_unconfigure()
    except UsageError as e:
        tw = py.io.TerminalWriter(sys.stderr)
        for msg in e.args:
            tw.line("ERROR: {}\n".format(msg), red=True)
        return EXIT_USAGEERROR


class cmdline(object):  # compatibility namespace
    main = staticmethod(main)


def filename_arg(path, optname):
    """ Argparse type validator for filename arguments.

    :path: path of filename
    :optname: name of the option
    """
    if os.path.isdir(path):
        raise UsageError("{} must be a filename, given: {}".format(optname, path))
    return path


def directory_arg(path, optname):
    """Argparse type validator for directory arguments.

    :path: path of directory
    :optname: name of the option
    """
    if not os.path.isdir(path):
        raise UsageError("{} must be a directory, given: {}".format(optname, path))
    return path


default_plugins = (
    "mark",
    "main",
    "terminal",
    "runner",
    "python",
    "fixtures",
    "debugging",
    "unittest",
    "capture",
    "skipping",
    "tmpdir",
    "monkeypatch",
    "recwarn",
    "pastebin",
    "helpconfig",
    "nose",
    "assertion",
    "junitxml",
    "resultlog",
    "doctest",
    "cacheprovider",
    "freeze_support",
    "setuponly",
    "setupplan",
    "stepwise",
    "warnings",
    "logging",
)


builtin_plugins = set(default_plugins)
builtin_plugins.add("pytester")


def get_config():
    # subsequent calls to main will create a fresh instance
    pluginmanager = PytestPluginManager()
    config = Config(pluginmanager)
    for spec in default_plugins:
        pluginmanager.import_plugin(spec)
    return config


def get_plugin_manager():
    """
    Obtain a new instance of the
    :py:class:`_pytest.config.PytestPluginManager`, with default plugins
    already loaded.

    This function can be used by integration with other tools, like hooking
    into pytest to run tests into an IDE.
    """
    return get_config().pluginmanager


def _prepareconfig(args=None, plugins=None):
    warning = None
    if args is None:
        args = sys.argv[1:]
    elif isinstance(args, py.path.local):
        args = [str(args)]
    elif not isinstance(args, (tuple, list)):
        if not isinstance(args, str):
            raise ValueError("not a string or argument list: %r" % (args,))
        args = shlex.split(args, posix=sys.platform != "win32")
        from _pytest import deprecated

        warning = deprecated.MAIN_STR_ARGS
    config = get_config()
    pluginmanager = config.pluginmanager
    try:
        if plugins:
            for plugin in plugins:
                if isinstance(plugin, six.string_types):
                    pluginmanager.consider_pluginarg(plugin)
                else:
                    pluginmanager.register(plugin)
        if warning:
            from _pytest.warnings import _issue_config_warning

            _issue_config_warning(warning, config=config)
        return pluginmanager.hook.pytest_cmdline_parse(
            pluginmanager=pluginmanager, args=args
        )
    except BaseException:
        config._ensure_unconfigure()
        raise


class PytestPluginManager(PluginManager):
    """
    Overwrites :py:class:`pluggy.PluginManager <pluggy.PluginManager>` to add pytest-specific
    functionality:

    * loading plugins from the command line, ``PYTEST_PLUGINS`` env variable and
      ``pytest_plugins`` global variables found in plugins being loaded;
    * ``conftest.py`` loading during start-up;
    """

    def __init__(self):
        super(PytestPluginManager, self).__init__("pytest")
        self._conftest_plugins = set()

        # state related to local conftest plugins
        self._dirpath2confmods = {}
        self._conftestpath2mod = {}
        self._confcutdir = None
        self._noconftest = False
        self._duplicatepaths = set()

        self.add_hookspecs(_pytest.hookspec)
        self.register(self)
        if os.environ.get("PYTEST_DEBUG"):
            err = sys.stderr
            encoding = getattr(err, "encoding", "utf8")
            try:
                err = py.io.dupfile(err, encoding=encoding)
            except Exception:
                pass
            self.trace.root.setwriter(err.write)
            self.enable_tracing()

        # Config._consider_importhook will set a real object if required.
        self.rewrite_hook = _pytest.assertion.DummyRewriteHook()
        # Used to know when we are importing conftests after the pytest_configure stage
        self._configured = False

    def addhooks(self, module_or_class):
        """
        .. deprecated:: 2.8

        Use :py:meth:`pluggy.PluginManager.add_hookspecs <PluginManager.add_hookspecs>`
        instead.
        """
        warning = dict(
            code="I2",
            fslocation=_pytest._code.getfslineno(sys._getframe(1)),
            nodeid=None,
            message="use pluginmanager.add_hookspecs instead of "
            "deprecated addhooks() method.",
        )
        self._warn(warning)
        return self.add_hookspecs(module_or_class)

    def parse_hookimpl_opts(self, plugin, name):
        # pytest hooks are always prefixed with pytest_
        # so we avoid accessing possibly non-readable attributes
        # (see issue #1073)
        if not name.startswith("pytest_"):
            return
        # ignore some historic special names which can not be hooks anyway
        if name == "pytest_plugins" or name.startswith("pytest_funcarg__"):
            return

        method = getattr(plugin, name)
        opts = super(PytestPluginManager, self).parse_hookimpl_opts(plugin, name)

        # consider only actual functions for hooks (#3775)
        if not inspect.isroutine(method):
            return

        # collect unmarked hooks as long as they have the `pytest_' prefix
        if opts is None and name.startswith("pytest_"):
            opts = {}

        if opts is not None:
            for name in ("tryfirst", "trylast", "optionalhook", "hookwrapper"):
                opts.setdefault(name, hasattr(method, name))
        return opts

    def parse_hookspec_opts(self, module_or_class, name):
        opts = super(PytestPluginManager, self).parse_hookspec_opts(
            module_or_class, name
        )
        if opts is None:
            method = getattr(module_or_class, name)
            if name.startswith("pytest_"):
                opts = {
                    "firstresult": hasattr(method, "firstresult"),
                    "historic": hasattr(method, "historic"),
                }
        return opts

    def register(self, plugin, name=None):
        if name in ["pytest_catchlog", "pytest_capturelog"]:
            self._warn(
                "{} plugin has been merged into the core, "
                "please remove it from your requirements.".format(
                    name.replace("_", "-")
                )
            )
            return
        ret = super(PytestPluginManager, self).register(plugin, name)
        if ret:
            self.hook.pytest_plugin_registered.call_historic(
                kwargs=dict(plugin=plugin, manager=self)
            )

            if isinstance(plugin, types.ModuleType):
                self.consider_module(plugin)
        return ret

    def getplugin(self, name):
        # support deprecated naming because plugins (xdist e.g.) use it
        return self.get_plugin(name)

    def hasplugin(self, name):
        """Return True if the plugin with the given name is registered."""
        return bool(self.get_plugin(name))

    def pytest_configure(self, config):
        # XXX now that the pluginmanager exposes hookimpl(tryfirst...)
        # we should remove tryfirst/trylast as markers
        config.addinivalue_line(
            "markers",
            "tryfirst: mark a hook implementation function such that the "
            "plugin machinery will try to call it first/as early as possible.",
        )
        config.addinivalue_line(
            "markers",
            "trylast: mark a hook implementation function such that the "
            "plugin machinery will try to call it last/as late as possible.",
        )
        self._configured = True

    def _warn(self, message):
        kwargs = (
            message
            if isinstance(message, dict)
            else {"code": "I1", "message": message, "fslocation": None, "nodeid": None}
        )
        self.hook.pytest_logwarning.call_historic(kwargs=kwargs)

    #
    # internal API for local conftest plugin handling
    #
    def _set_initial_conftests(self, namespace):
        """ load initial conftest files given a preparsed "namespace".
            As conftest files may add their own command line options
            which have arguments ('--my-opt somepath') we might get some
            false positives.  All builtin and 3rd party plugins will have
            been loaded, however, so common options will not confuse our logic
            here.
        """
        current = py.path.local()
        self._confcutdir = (
            current.join(namespace.confcutdir, abs=True)
            if namespace.confcutdir
            else None
        )
        self._noconftest = namespace.noconftest
        self._using_pyargs = namespace.pyargs
        testpaths = namespace.file_or_dir
        foundanchor = False
        for path in testpaths:
            path = str(path)
            # remove node-id syntax
            i = path.find("::")
            if i != -1:
                path = path[:i]
            anchor = current.join(path, abs=1)
            if exists(anchor):  # we found some file object
                self._try_load_conftest(anchor)
                foundanchor = True
        if not foundanchor:
            self._try_load_conftest(current)

    def _try_load_conftest(self, anchor):
        self._getconftestmodules(anchor)
        # let's also consider test* subdirs
        if anchor.check(dir=1):
            for x in anchor.listdir("test*"):
                if x.check(dir=1):
                    self._getconftestmodules(x)

    @lru_cache(maxsize=128)
    def _getconftestmodules(self, path):
        if self._noconftest:
            return []

        if path.isfile():
            directory = path.dirpath()
        else:
            directory = path

        if six.PY2:  # py2 is not using lru_cache.
            try:
                return self._dirpath2confmods[directory]
            except KeyError:
                pass

        # XXX these days we may rather want to use config.rootdir
        # and allow users to opt into looking into the rootdir parent
        # directories instead of requiring to specify confcutdir
        clist = []
        for parent in directory.realpath().parts():
            if self._confcutdir and self._confcutdir.relto(parent):
                continue
            conftestpath = parent.join("conftest.py")
            if conftestpath.isfile():
                mod = self._importconftest(conftestpath)
                clist.append(mod)
        self._dirpath2confmods[directory] = clist
        return clist

    def _rget_with_confmod(self, name, path):
        modules = self._getconftestmodules(path)
        for mod in reversed(modules):
            try:
                return mod, getattr(mod, name)
            except AttributeError:
                continue
        raise KeyError(name)

    def _importconftest(self, conftestpath):
        try:
            return self._conftestpath2mod[conftestpath]
        except KeyError:
            pkgpath = conftestpath.pypkgpath()
            if pkgpath is None:
                _ensure_removed_sysmodule(conftestpath.purebasename)
            try:
                mod = conftestpath.pyimport()
                if (
                    hasattr(mod, "pytest_plugins")
                    and self._configured
                    and not self._using_pyargs
                ):
                    from _pytest.deprecated import (
                        PYTEST_PLUGINS_FROM_NON_TOP_LEVEL_CONFTEST
                    )

                    warnings.warn_explicit(
                        PYTEST_PLUGINS_FROM_NON_TOP_LEVEL_CONFTEST,
                        category=None,
                        filename=str(conftestpath),
                        lineno=0,
                    )
            except Exception:
                raise ConftestImportFailure(conftestpath, sys.exc_info())

            self._conftest_plugins.add(mod)
            self._conftestpath2mod[conftestpath] = mod
            dirpath = conftestpath.dirpath()
            if dirpath in self._dirpath2confmods:
                for path, mods in self._dirpath2confmods.items():
                    if path and path.relto(dirpath) or path == dirpath:
                        assert mod not in mods
                        mods.append(mod)
            self.trace("loaded conftestmodule %r" % (mod))
            self.consider_conftest(mod)
            return mod

    #
    # API for bootstrapping plugin loading
    #
    #

    def consider_preparse(self, args):
        for opt1, opt2 in zip(args, args[1:]):
            if opt1 == "-p":
                self.consider_pluginarg(opt2)

    def consider_pluginarg(self, arg):
        if arg.startswith("no:"):
            name = arg[3:]
            self.set_blocked(name)
            if not name.startswith("pytest_"):
                self.set_blocked("pytest_" + name)
        else:
            self.import_plugin(arg)

    def consider_conftest(self, conftestmodule):
        self.register(conftestmodule, name=conftestmodule.__file__)

    def consider_env(self):
        self._import_plugin_specs(os.environ.get("PYTEST_PLUGINS"))

    def consider_module(self, mod):
        self._import_plugin_specs(getattr(mod, "pytest_plugins", []))

    def _import_plugin_specs(self, spec):
        plugins = _get_plugin_specs_as_list(spec)
        for import_spec in plugins:
            self.import_plugin(import_spec)

    def import_plugin(self, modname):
        # most often modname refers to builtin modules, e.g. "pytester",
        # "terminal" or "capture".  Those plugins are registered under their
        # basename for historic purposes but must be imported with the
        # _pytest prefix.
        assert isinstance(modname, (six.text_type, str)), (
            "module name as text required, got %r" % modname
        )
        modname = str(modname)
        if self.is_blocked(modname) or self.get_plugin(modname) is not None:
            return
        if modname in builtin_plugins:
            importspec = "_pytest." + modname
        else:
            importspec = modname
        self.rewrite_hook.mark_rewrite(importspec)
        try:
            __import__(importspec)
        except ImportError as e:
            new_exc_type = ImportError
            new_exc_message = 'Error importing plugin "%s": %s' % (
                modname,
                safe_str(e.args[0]),
            )
            new_exc = new_exc_type(new_exc_message)

            six.reraise(new_exc_type, new_exc, sys.exc_info()[2])

        except Skipped as e:
            self._warn("skipped plugin %r: %s" % ((modname, e.msg)))
        else:
            mod = sys.modules[importspec]
            self.register(mod, modname)


def _get_plugin_specs_as_list(specs):
    """
    Parses a list of "plugin specs" and returns a list of plugin names.

    Plugin specs can be given as a list of strings separated by "," or already as a list/tuple in
    which case it is returned as a list. Specs can also be `None` in which case an
    empty list is returned.
    """
    if specs is not None:
        if isinstance(specs, str):
            specs = specs.split(",") if specs else []
        if not isinstance(specs, (list, tuple)):
            raise UsageError(
                "Plugin specs must be a ','-separated string or a "
                "list/tuple of strings for plugin names. Given: %r" % specs
            )
        return list(specs)
    return []


def _ensure_removed_sysmodule(modname):
    try:
        del sys.modules[modname]
    except KeyError:
        pass


class Notset(object):
    def __repr__(self):
        return "<NOTSET>"


notset = Notset()


def _iter_rewritable_modules(package_files):
    for fn in package_files:
        is_simple_module = "/" not in fn and fn.endswith(".py")
        is_package = fn.count("/") == 1 and fn.endswith("__init__.py")
        if is_simple_module:
            module_name, _ = os.path.splitext(fn)
            yield module_name
        elif is_package:
            package_name = os.path.dirname(fn)
            yield package_name


class Config(object):
    """ access to configuration values, pluginmanager and plugin hooks.  """

    def __init__(self, pluginmanager):
        #: 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),
            processopt=self._processopt,
        )
        #: a pluginmanager instance
        self.pluginmanager = pluginmanager
        self.trace = self.pluginmanager.trace.root.get("config")
        self.hook = self.pluginmanager.hook
        self._inicache = {}
        self._override_ini = ()
        self._opt2dest = {}
        self._cleanup = []
        self._warn = self.pluginmanager._warn
        self.pluginmanager.register(self, "pytestconfig")
        self._configured = False

        def do_setns(dic):
            import pytest

            setns(pytest, dic)

        self.hook.pytest_namespace.call_historic(do_setns, {})
        self.hook.pytest_addoption.call_historic(kwargs=dict(parser=self._parser))

    def add_cleanup(self, func):
        """ Add a function to be called when the config object gets out of
        use (usually coninciding with pytest_unconfigure)."""
        self._cleanup.append(func)

    def _do_configure(self):
        assert not self._configured
        self._configured = True
        self.hook.pytest_configure.call_historic(kwargs=dict(config=self))

    def _ensure_unconfigure(self):
        if self._configured:
            self._configured = False
            self.hook.pytest_unconfigure(config=self)
            self.hook.pytest_configure._call_history = []
        while self._cleanup:
            fin = self._cleanup.pop()
            fin()

    def warn(self, code, message, fslocation=None, nodeid=None):
        """
        .. deprecated:: 3.8

            Use :py:func:`warnings.warn` or :py:func:`warnings.warn_explicit` directly instead.

        Generate a warning for this test session.
        """
        from _pytest.warning_types import RemovedInPytest4Warning

        if isinstance(fslocation, (tuple, list)) and len(fslocation) > 2:
            filename, lineno = fslocation[:2]
        else:
            filename = "unknown file"
            lineno = 0
        msg = "config.warn has been deprecated, use warnings.warn instead"
        if nodeid:
            msg = "{}: {}".format(nodeid, msg)
        warnings.warn_explicit(
            RemovedInPytest4Warning(msg),
            category=None,
            filename=filename,
            lineno=lineno,
        )
        self.hook.pytest_logwarning.call_historic(
            kwargs=dict(
                code=code, message=message, fslocation=fslocation, nodeid=nodeid
            )
        )

    def get_terminal_writer(self):
        return self.pluginmanager.get_plugin("terminalreporter")._tw

    def pytest_cmdline_parse(self, pluginmanager, args):
        # REF1 assert self == pluginmanager.config, (self, pluginmanager.config)
        self.parse(args)
        return self

    def notify_exception(self, excinfo, option=None):
        if option and option.fulltrace:
            style = "long"
        else:
            style = "native"
        excrepr = excinfo.getrepr(
            funcargs=True, showlocals=getattr(option, "showlocals", False), style=style
        )
        res = self.hook.pytest_internalerror(excrepr=excrepr, excinfo=excinfo)
        if not any(res):
            for line in str(excrepr).split("\n"):
                sys.stderr.write("INTERNALERROR> %s\n" % line)
                sys.stderr.flush()

    def cwd_relative_nodeid(self, nodeid):
        # nodeid's are relative to the rootpath, compute relative to cwd
        if self.invocation_dir != self.rootdir:
            fullpath = self.rootdir.join(nodeid)
            nodeid = self.invocation_dir.bestrelpath(fullpath)
        return nodeid

    @classmethod
    def fromdictargs(cls, option_dict, args):
        """ constructor useable for subprocesses. """
        config = get_config()
        config.option.__dict__.update(option_dict)
        config.parse(args, addopts=False)
        for x in config.option.plugins:
            config.pluginmanager.consider_pluginarg(x)
        return config

    def _processopt(self, opt):
        for name in opt._short_opts + opt._long_opts:
            self._opt2dest[name] = opt.dest

        if hasattr(opt, "default") and opt.dest:
            if not hasattr(self.option, opt.dest):
                setattr(self.option, opt.dest, opt.default)

    @hookimpl(trylast=True)
    def pytest_load_initial_conftests(self, early_config):
        self.pluginmanager._set_initial_conftests(early_config.known_args_namespace)

    def _initini(self, args):
        ns, unknown_args = self._parser.parse_known_and_unknown_args(
            args, namespace=copy.copy(self.option)
        )
        r = determine_setup(
            ns.inifilename,
            ns.file_or_dir + unknown_args,
            rootdir_cmd_arg=ns.rootdir or None,
            config=self,
        )
        self.rootdir, self.inifile, self.inicfg = r
        self._parser.extra_info["rootdir"] = self.rootdir
        self._parser.extra_info["inifile"] = self.inifile
        self.invocation_dir = py.path.local()
        self._parser.addini("addopts", "extra command line options", "args")
        self._parser.addini("minversion", "minimally required pytest version")
        self._override_ini = ns.override_ini or ()

    def _consider_importhook(self, args):
        """Install the PEP 302 import hook if using assertion rewriting.

        Needs to parse the --assert=<mode> option from the commandline
        and find all the installed plugins to mark them for rewriting
        by the importhook.
        """
        ns, unknown_args = self._parser.parse_known_and_unknown_args(args)
        mode = ns.assertmode
        if mode == "rewrite":
            try:
                hook = _pytest.assertion.install_importhook(self)
            except SystemError:
                mode = "plain"
            else:
                self._mark_plugins_for_rewrite(hook)
        _warn_about_missing_assertion(mode)

    def _mark_plugins_for_rewrite(self, hook):
        """
        Given an importhook, mark for rewrite any top-level
        modules or packages in the distribution package for
        all pytest plugins.
        """
        import pkg_resources

        self.pluginmanager.rewrite_hook = hook

        if os.environ.get("PYTEST_DISABLE_PLUGIN_AUTOLOAD"):
            # We don't autoload from setuptools entry points, no need to continue.
            return

        # 'RECORD' available for plugins installed normally (pip install)
        # 'SOURCES.txt' available for plugins installed in dev mode (pip install -e)
        # for installed plugins 'SOURCES.txt' returns an empty list, and vice-versa
        # so it shouldn't be an issue
        metadata_files = "RECORD", "SOURCES.txt"

        package_files = (
            entry.split(",")[0]
            for entrypoint in pkg_resources.iter_entry_points("pytest11")
            for metadata in metadata_files
            for entry in entrypoint.dist._get_metadata(metadata)
        )

        for name in _iter_rewritable_modules(package_files):
            hook.mark_rewrite(name)

    def _preparse(self, args, addopts=True):
        if addopts:
            args[:] = shlex.split(os.environ.get("PYTEST_ADDOPTS", "")) + args
        self._initini(args)
        if addopts:
            args[:] = self.getini("addopts") + args
        self._checkversion()
        self._consider_importhook(args)
        self.pluginmanager.consider_preparse(args)
        if not os.environ.get("PYTEST_DISABLE_PLUGIN_AUTOLOAD"):
            # Don't autoload from setuptools entry point. Only explicitly specified
            # plugins are going to be loaded.
            self.pluginmanager.load_setuptools_entrypoints("pytest11")
        self.pluginmanager.consider_env()
        self.known_args_namespace = ns = self._parser.parse_known_args(
            args, namespace=copy.copy(self.option)
        )
        if self.known_args_namespace.confcutdir is None and self.inifile:
            confcutdir = py.path.local(self.inifile).dirname
            self.known_args_namespace.confcutdir = confcutdir
        try:
            self.hook.pytest_load_initial_conftests(
                early_config=self, args=args, parser=self._parser
            )
        except ConftestImportFailure:
            e = sys.exc_info()[1]
            if ns.help or ns.version:
                # we don't want to prevent --help/--version to work
                # so just let is pass and print a warning at the end
                self._warn("could not load initial conftests (%s)\n" % e.path)
            else:
                raise

    def _checkversion(self):
        import pytest

        minver = self.inicfg.get("minversion", None)
        if minver:
            if LooseVersion(minver) > LooseVersion(pytest.__version__):
                raise pytest.UsageError(
                    "%s:%d: requires pytest-%s, actual pytest-%s'"
                    % (
                        self.inicfg.config.path,
                        self.inicfg.lineof("minversion"),
                        minver,
                        pytest.__version__,
                    )
                )

    def parse(self, args, addopts=True):
        # parse given cmdline arguments into this config object.
        assert not hasattr(
            self, "args"
        ), "can only parse cmdline args at most once per Config object"
        self._origargs = args
        self.hook.pytest_addhooks.call_historic(
            kwargs=dict(pluginmanager=self.pluginmanager)
        )
        self._preparse(args, addopts=addopts)
        # XXX deprecated hook:
        self.hook.pytest_cmdline_preparse(config=self, args=args)
        self._parser.after_preparse = True
        try:
            args = self._parser.parse_setoption(
                args, self.option, namespace=self.option
            )
            if not args:
                cwd = os.getcwd()
                if cwd == self.rootdir:
                    args = self.getini("testpaths")
                if not args:
                    args = [cwd]
            self.args = args
        except PrintHelp:
            pass

    def addinivalue_line(self, name, line):
        """ add a line to an ini-file option. The option must have been
        declared but might not yet be set in which case the line becomes the
        the first line in its value. """
        x = self.getini(name)
        assert isinstance(x, list)
        x.append(line)  # modifies the cached list inline

    def getini(self, name):
        """ return configuration value from an :ref:`ini file <inifiles>`. If the
        specified name hasn't been registered through a prior
        :py:func:`parser.addini <_pytest.config.Parser.addini>`
        call (usually from a plugin), a ValueError is raised. """
        try:
            return self._inicache[name]
        except KeyError:
            self._inicache[name] = val = self._getini(name)
            return val

    def _getini(self, name):
        try:
            description, type, default = self._parser._inidict[name]
        except KeyError:
            raise ValueError("unknown configuration value: %r" % (name,))
        value = self._get_override_ini_value(name)
        if value is None:
            try:
                value = self.inicfg[name]
            except KeyError:
                if default is not None:
                    return default
                if type is None:
                    return ""
                return []
        if type == "pathlist":
            dp = py.path.local(self.inicfg.config.path).dirpath()
            values = []
            for relpath in shlex.split(value):
                values.append(dp.join(relpath, abs=True))
            return values
        elif type == "args":
            return shlex.split(value)
        elif type == "linelist":
            return [t for t in map(lambda x: x.strip(), value.split("\n")) if t]
        elif type == "bool":
            return bool(_strtobool(value.strip()))
        else:
            assert type is None
            return value

    def _getconftest_pathlist(self, name, path):
        try:
            mod, relroots = self.pluginmanager._rget_with_confmod(name, path)
        except KeyError:
            return None
        modpath = py.path.local(mod.__file__).dirpath()
        values = []
        for relroot in relroots:
            if not isinstance(relroot, py.path.local):
                relroot = relroot.replace("/", py.path.local.sep)
                relroot = modpath.join(relroot, abs=True)
            values.append(relroot)
        return values

    def _get_override_ini_value(self, name):
        value = None
        # override_ini is a list of "ini=value" options
        # always use the last item if multiple values are set for same ini-name,
        # e.g. -o foo=bar1 -o foo=bar2 will set foo to bar2
        for ini_config in self._override_ini:
            try:
                key, user_ini_value = ini_config.split("=", 1)
            except ValueError:
                raise UsageError("-o/--override-ini expects option=value style.")
            else:
                if key == name:
                    value = user_ini_value
        return value

    def getoption(self, name, default=notset, skip=False):
        """ return command line option value.

        :arg name: name of the option.  You may also specify
            the literal ``--OPT`` option instead of the "dest" option name.
        :arg default: default value if no option of that name exists.
        :arg skip: if True raise pytest.skip if option does not exists
            or has a None value.
        """
        name = self._opt2dest.get(name, name)
        try:
            val = getattr(self.option, name)
            if val is None and skip:
                raise AttributeError(name)
            return val
        except AttributeError:
            if default is not notset:
                return default
            if skip:
                import pytest

                pytest.skip("no %r option found" % (name,))
            raise ValueError("no option named %r" % (name,))

    def getvalue(self, name, path=None):
        """ (deprecated, use getoption()) """
        return self.getoption(name)

    def getvalueorskip(self, name, path=None):
        """ (deprecated, use getoption(skip=True)) """
        return self.getoption(name, skip=True)


def _assertion_supported():
    try:
        assert False
    except AssertionError:
        return True
    else:
        return False


def _warn_about_missing_assertion(mode):
    if not _assertion_supported():
        if mode == "plain":
            sys.stderr.write(
                "WARNING: ASSERTIONS ARE NOT EXECUTED"
                " and FAILING TESTS WILL PASS.  Are you"
                " using python -O?"
            )
        else:
            sys.stderr.write(
                "WARNING: assertions not in test modules or"
                " plugins will be ignored"
                " because assert statements are not executed "
                "by the underlying Python interpreter "
                "(are you using python -O?)\n"
            )


def setns(obj, dic):
    import pytest

    for name, value in dic.items():
        if isinstance(value, dict):
            mod = getattr(obj, name, None)
            if mod is None:
                modname = "pytest.%s" % name
                mod = types.ModuleType(modname)
                sys.modules[modname] = mod
                mod.__all__ = []
                setattr(obj, name, mod)
            obj.__all__.append(name)
            setns(mod, value)
        else:
            setattr(obj, name, value)
            obj.__all__.append(name)
            # if obj != pytest:
            #    pytest.__all__.append(name)
            setattr(pytest, name, value)


def create_terminal_writer(config, *args, **kwargs):
    """Create a TerminalWriter instance configured according to the options
    in the config object. Every code which requires a TerminalWriter object
    and has access to a config object should use this function.
    """
    tw = py.io.TerminalWriter(*args, **kwargs)
    if config.option.color == "yes":
        tw.hasmarkup = True
    if config.option.color == "no":
        tw.hasmarkup = False
    return tw


def _strtobool(val):
    """Convert a string representation of truth to true (1) or false (0).

    True values are 'y', 'yes', 't', 'true', 'on', and '1'; false values
    are 'n', 'no', 'f', 'false', 'off', and '0'.  Raises ValueError if
    'val' is anything else.

    .. note:: copied from distutils.util
    """
    val = val.lower()
    if val in ("y", "yes", "t", "true", "on", "1"):
        return 1
    elif val in ("n", "no", "f", "false", "off", "0"):
        return 0
    else:
        raise ValueError("invalid truth value %r" % (val,))