text: """Core implementation of the testing process: init, session, runtest loop."""
  import argparse
  import fnmatch
  import functools
  import importlib
  import os
  import sys
  from pathlib import Path
  from typing import Callable
  from typing import Dict
  from typing import FrozenSet
  from typing import Iterator
  from typing import List
  from typing import Optional
  from typing import overload
  from typing import Sequence
  from typing import Set
  from typing import Tuple
  from typing import Type
  from typing import TYPE_CHECKING
  from typing import Union
  
  import attr
  
  import _pytest._code
  from _pytest import nodes
  from _pytest.compat import final
  from _pytest.compat import LEGACY_PATH
  from _pytest.compat import legacy_path
  from _pytest.config import Config
  from _pytest.config import directory_arg
  from _pytest.config import ExitCode
  from _pytest.config import hookimpl
  from _pytest.config import PytestPluginManager
  from _pytest.config import UsageError
  from _pytest.config.argparsing import Parser
  from _pytest.fixtures import FixtureManager
  from _pytest.outcomes import exit
  from _pytest.pathlib import absolutepath
  from _pytest.pathlib import bestrelpath
  from _pytest.pathlib import fnmatch_ex
  from _pytest.pathlib import visit
  from _pytest.reports import CollectReport
  from _pytest.reports import TestReport
  from _pytest.runner import collect_one_node
  from _pytest.runner import SetupState
  
  
  if TYPE_CHECKING:
      from typing_extensions import Literal
  
  
  def pytest_addoption(parser: Parser) -> None:
      parser.addini(
          "norecursedirs",
          "directory patterns to avoid for recursion",
          type="args",
          default=[
              "*.egg",
              ".*",
              "_darcs",
              "build",
              "CVS",
              "dist",
              "node_modules",
              "venv",
              "{arch}",
          ],
      )
      parser.addini(
          "testpaths",
          "directories to search for tests when no files or directories are given in the "
          "command line.",
          type="args",
          default=[],
      )
      group = parser.getgroup("general", "running and selection options")
      group._addoption(
          "-x",
          "--exitfirst",
          action="store_const",
          dest="maxfail",
          const=1,
          help="exit instantly on first error or failed test.",
      )
      group = parser.getgroup("pytest-warnings")
      group.addoption(
          "-W",
          "--pythonwarnings",
          action="append",
          help="set which warnings to report, see -W option of python itself.",
      )
      parser.addini(
          "filterwarnings",
          type="linelist",
          help="Each line specifies a pattern for "
          "warnings.filterwarnings. "
          "Processed after -W/--pythonwarnings.",
      )
      group._addoption(
          "--maxfail",
          metavar="num",
          action="store",
          type=int,
          dest="maxfail",
          default=0,
          help="exit after first num failures or errors.",
      )
      group._addoption(
          "--strict-config",
          action="store_true",
          help="any warnings encountered while parsing the `pytest` section of the configuration file raise errors.",
      )
      group._addoption(
          "--strict-markers",
          action="store_true",
          help="markers not registered in the `markers` section of the configuration file raise errors.",
      )
      group._addoption(
          "--strict",
          action="store_true",
          help="(deprecated) alias to --strict-markers.",
      )
      group._addoption(
          "-c",
          metavar="file",
          type=str,
          dest="inifilename",
          help="load configuration from `file` instead of trying to locate one of the implicit "
          "configuration files.",
      )
      group._addoption(
          "--continue-on-collection-errors",
          action="store_true",
          default=False,
          dest="continue_on_collection_errors",
          help="Force test execution even if collection errors occur.",
      )
      group._addoption(
          "--rootdir",
          action="store",
          dest="rootdir",
          help="Define root directory for tests. Can be relative path: 'root_dir', './root_dir', "
          "'root_dir/another_dir/'; absolute path: '/home/user/root_dir'; path with variables: "
          "'$HOME/root_dir'.",
      )
  
      group = parser.getgroup("collect", "collection")
      group.addoption(
          "--collectonly",
          "--collect-only",
          "--co",
          action="store_true",
          help="only collect tests, don't execute them.",
      )
      group.addoption(
          "--pyargs",
          action="store_true",
          help="try to interpret all arguments as python packages.",
      )
      group.addoption(
          "--ignore",
          action="append",
          metavar="path",
          help="ignore path during collection (multi-allowed).",
      )
      group.addoption(
          "--ignore-glob",
          action="append",
          metavar="path",
          help="ignore path pattern during collection (multi-allowed).",
      )
      group.addoption(
          "--deselect",
          action="append",
          metavar="nodeid_prefix",
          help="deselect item (via node id prefix) during collection (multi-allowed).",
      )
      group.addoption(
          "--confcutdir",
          dest="confcutdir",
          default=None,
          metavar="dir",
          type=functools.partial(directory_arg, optname="--confcutdir"),
          help="only load conftest.py's relative to specified dir.",
      )
      group.addoption(
          "--noconftest",
          action="store_true",
          dest="noconftest",
          default=False,
          help="Don't load any conftest.py files.",
      )
      group.addoption(
          "--keepduplicates",
          "--keep-duplicates",
          action="store_true",
          dest="keepduplicates",
          default=False,
          help="Keep duplicate tests.",
      )
      group.addoption(
          "--collect-in-virtualenv",
          action="store_true",
          dest="collect_in_virtualenv",
          default=False,
          help="Don't ignore tests in a local virtualenv directory",
      )
      group.addoption(
          "--import-mode",
          default="prepend",
          choices=["prepend", "append", "importlib"],
          dest="importmode",
          help="prepend/append to sys.path when importing test modules and conftest files, "
          "default is to prepend.",
      )
  
      group = parser.getgroup("debugconfig", "test session debugging and configuration")
      group.addoption(
          "--basetemp",
          dest="basetemp",
          default=None,
          type=validate_basetemp,
          metavar="dir",
          help=(
              "base temporary directory for this test run."
              "(warning: this directory is removed if it exists)"
          ),
      )
  
  
  def validate_basetemp(path: str) -> str:
      # GH 7119
      msg = "basetemp must not be empty, the current working directory or any parent directory of it"
  
      # empty path
      if not path:
          raise argparse.ArgumentTypeError(msg)
  
      def is_ancestor(base: Path, query: Path) -> bool:
          """Return whether query is an ancestor of base."""
          if base == query:
              return True
          for parent in base.parents:
              if parent == query:
                  return True
          return False
  
      # check if path is an ancestor of cwd
      if is_ancestor(Path.cwd(), Path(path).absolute()):
          raise argparse.ArgumentTypeError(msg)
  
      # check symlinks for ancestors
      if is_ancestor(Path.cwd().resolve(), Path(path).resolve()):
          raise argparse.ArgumentTypeError(msg)
  
      return path
  
  
  def wrap_session(
      config: Config, doit: Callable[[Config, "Session"], Optional[Union[int, ExitCode]]]
  ) -> Union[int, ExitCode]:
      """Skeleton command line program."""
      session = Session.from_config(config)
      session.exitstatus = ExitCode.OK
      initstate = 0
      try:
          try:
              config._do_configure()
              initstate = 1
              config.hook.pytest_sessionstart(session=session)
              initstate = 2
              session.exitstatus = doit(config, session) or 0
          except UsageError:
              session.exitstatus = ExitCode.USAGE_ERROR
              raise
          except Failed:
              session.exitstatus = ExitCode.TESTS_FAILED
          except (KeyboardInterrupt, exit.Exception):
              excinfo = _pytest._code.ExceptionInfo.from_current()
              exitstatus: Union[int, ExitCode] = ExitCode.INTERRUPTED
              if isinstance(excinfo.value, exit.Exception):
                  if excinfo.value.returncode is not None:
                      exitstatus = excinfo.value.returncode
                  if initstate < 2:
                      sys.stderr.write(f"{excinfo.typename}: {excinfo.value.msg}\n")
              config.hook.pytest_keyboard_interrupt(excinfo=excinfo)
              session.exitstatus = exitstatus
          except BaseException:
              session.exitstatus = ExitCode.INTERNAL_ERROR
              excinfo = _pytest._code.ExceptionInfo.from_current()
              try:
                  config.notify_exception(excinfo, config.option)
              except exit.Exception as exc:
                  if exc.returncode is not None:
                      session.exitstatus = exc.returncode
                  sys.stderr.write("{}: {}\n".format(type(exc).__name__, exc))
              else:
                  if isinstance(excinfo.value, SystemExit):
                      sys.stderr.write("mainloop: caught unexpected SystemExit!\n")
  
      finally:
          # Explicitly break reference cycle.
          excinfo = None  # type: ignore
          os.chdir(session.startpath)
          if initstate >= 2:
              try:
                  config.hook.pytest_sessionfinish(
                      session=session, exitstatus=session.exitstatus
                  )
              except exit.Exception as exc:
                  if exc.returncode is not None:
                      session.exitstatus = exc.returncode
                  sys.stderr.write("{}: {}\n".format(type(exc).__name__, exc))
          config._ensure_unconfigure()
      return session.exitstatus
  
  
  def pytest_cmdline_main(config: Config) -> Union[int, ExitCode]:
      return wrap_session(config, _main)
  
  
  def _main(config: Config, session: "Session") -> Optional[Union[int, ExitCode]]:
      """Default command line protocol for initialization, session,
      running tests and reporting."""
      config.hook.pytest_collection(session=session)
      config.hook.pytest_runtestloop(session=session)
  
      if session.testsfailed:
          return ExitCode.TESTS_FAILED
      elif session.testscollected == 0:
          return ExitCode.NO_TESTS_COLLECTED
      return None
  
  
  def pytest_collection(session: "Session") -> None:
      session.perform_collect()
  
  
  def pytest_runtestloop(session: "Session") -> bool:
      if session.testsfailed and not session.config.option.continue_on_collection_errors:
          raise session.Interrupted(
              "%d error%s during collection"
              % (session.testsfailed, "s" if session.testsfailed != 1 else "")
          )
  
      if session.config.option.collectonly:
          return True
  
      for i, item in enumerate(session.items):
          nextitem = session.items[i + 1] if i + 1 < len(session.items) else None
          item.config.hook.pytest_runtest_protocol(item=item, nextitem=nextitem)
          if session.shouldfail:
              raise session.Failed(session.shouldfail)
          if session.shouldstop:
              raise session.Interrupted(session.shouldstop)
      return True
  
  
  def _in_venv(path: Path) -> bool:
      """Attempt to detect if ``path`` is the root of a Virtual Environment by
      checking for the existence of the appropriate activate script."""
      bindir = path.joinpath("Scripts" if sys.platform.startswith("win") else "bin")
      try:
          if not bindir.is_dir():
              return False
      except OSError:
          return False
      activates = (
          "activate",
          "activate.csh",
          "activate.fish",
          "Activate",
          "Activate.bat",
          "Activate.ps1",
      )
      return any(fname.name in activates for fname in bindir.iterdir())
  
  
  def pytest_ignore_collect(fspath: Path, config: Config) -> Optional[bool]:
      ignore_paths = config._getconftest_pathlist(
          "collect_ignore", path=fspath.parent, rootpath=config.rootpath
      )
      ignore_paths = ignore_paths or []
      excludeopt = config.getoption("ignore")
      if excludeopt:
          ignore_paths.extend(absolutepath(x) for x in excludeopt)
  
      if fspath in ignore_paths:
          return True
  
      ignore_globs = config._getconftest_pathlist(
          "collect_ignore_glob", path=fspath.parent, rootpath=config.rootpath
      )
      ignore_globs = ignore_globs or []
      excludeglobopt = config.getoption("ignore_glob")
      if excludeglobopt:
          ignore_globs.extend(absolutepath(x) for x in excludeglobopt)
  
      if any(fnmatch.fnmatch(str(fspath), str(glob)) for glob in ignore_globs):
          return True
  
      allow_in_venv = config.getoption("collect_in_virtualenv")
      if not allow_in_venv and _in_venv(fspath):
          return True
      return None
  
  
  def pytest_collection_modifyitems(items: List[nodes.Item], config: Config) -> None:
      deselect_prefixes = tuple(config.getoption("deselect") or [])
      if not deselect_prefixes:
          return
  
      remaining = []
      deselected = []
      for colitem in items:
          if colitem.nodeid.startswith(deselect_prefixes):
              deselected.append(colitem)
          else:
              remaining.append(colitem)
  
      if deselected:
          config.hook.pytest_deselected(items=deselected)
          items[:] = remaining
  
  
  class FSHookProxy:
      def __init__(self, pm: PytestPluginManager, remove_mods) -> None:
          self.pm = pm
          self.remove_mods = remove_mods
  
      def __getattr__(self, name: str):
          x = self.pm.subset_hook_caller(name, remove_plugins=self.remove_mods)
          self.__dict__[name] = x
          return x
  
  
  class Interrupted(KeyboardInterrupt):
      """Signals that the test run was interrupted."""
  
      __module__ = "builtins"  # For py3.
  
  
  class Failed(Exception):
      """Signals a stop as failed test run."""
  
  
  @attr.s
  class _bestrelpath_cache(Dict[Path, str]):
      path = attr.ib(type=Path)
  
      def __missing__(self, path: Path) -> str:
          r = bestrelpath(self.path, path)
          self[path] = r
          return r
  
  
  @final
  class Session(nodes.FSCollector):
      Interrupted = Interrupted
      Failed = Failed
      # Set on the session by runner.pytest_sessionstart.
      _setupstate: SetupState
      # Set on the session by fixtures.pytest_sessionstart.
      _fixturemanager: FixtureManager
      exitstatus: Union[int, ExitCode]
  
      def __init__(self, config: Config) -> None:
          super().__init__(
              path=config.rootpath,
              fspath=None,
              parent=None,
              config=config,
              session=self,
              nodeid="",
          )
          self.testsfailed = 0
          self.testscollected = 0
          self.shouldstop: Union[bool, str] = False
          self.shouldfail: Union[bool, str] = False
          self.trace = config.trace.root.get("collection")
          self._initialpaths: FrozenSet[Path] = frozenset()
  
          self._bestrelpathcache: Dict[Path, str] = _bestrelpath_cache(config.rootpath)
  
          self.config.pluginmanager.register(self, name="session")
  
      @classmethod
      def from_config(cls, config: Config) -> "Session":
          session: Session = cls._create(config)
          return session
  
      def __repr__(self) -> str:
          return "<%s %s exitstatus=%r testsfailed=%d testscollected=%d>" % (
              self.__class__.__name__,
              self.name,
              getattr(self, "exitstatus", "<UNSET>"),
              self.testsfailed,
              self.testscollected,
          )
  
      @property
      def startpath(self) -> Path:
          """The path from which pytest was invoked.
  
          .. versionadded:: 6.3.0
          """
          return self.config.invocation_params.dir
  
      @property
      def stardir(self) -> LEGACY_PATH:
          """The path from which pytest was invoked.
  
          Prefer to use ``startpath`` which is a :class:`pathlib.Path`.
  
          :type: LEGACY_PATH
          """
          return legacy_path(self.startpath)
  
      def _node_location_to_relpath(self, node_path: Path) -> str:
          # bestrelpath is a quite slow function.
          return self._bestrelpathcache[node_path]
  
      @hookimpl(tryfirst=True)
      def pytest_collectstart(self) -> None:
          if self.shouldfail:
              raise self.Failed(self.shouldfail)
          if self.shouldstop:
              raise self.Interrupted(self.shouldstop)
  
      @hookimpl(tryfirst=True)
      def pytest_runtest_logreport(
          self, report: Union[TestReport, CollectReport]
      ) -> None:
          if report.failed and not hasattr(report, "wasxfail"):
              self.testsfailed += 1
              maxfail = self.config.getvalue("maxfail")
              if maxfail and self.testsfailed >= maxfail:
                  self.shouldfail = "stopping after %d failures" % (self.testsfailed)
  
      pytest_collectreport = pytest_runtest_logreport
  
      def isinitpath(self, path: Union[str, "os.PathLike[str]"]) -> bool:
          return Path(path) in self._initialpaths
  
      def gethookproxy(self, fspath: "os.PathLike[str]"):
          # Check if we have the common case of running
          # hooks with all conftest.py files.
          pm = self.config.pluginmanager
          my_conftestmodules = pm._getconftestmodules(
              Path(fspath),
              self.config.getoption("importmode"),
              rootpath=self.config.rootpath,
          )
          remove_mods = pm._conftest_plugins.difference(my_conftestmodules)
          if remove_mods:
              # One or more conftests are not in use at this fspath.
              from .config.compat import PathAwareHookProxy
  
              proxy = PathAwareHookProxy(FSHookProxy(pm, remove_mods))
          else:
              # All plugins are active for this fspath.
              proxy = self.config.hook
          return proxy
  
      def _recurse(self, direntry: "os.DirEntry[str]") -> bool:
          if direntry.name == "__pycache__":
              return False
          fspath = Path(direntry.path)
          ihook = self.gethookproxy(fspath.parent)
          if ihook.pytest_ignore_collect(fspath=fspath, config=self.config):
              return False
          norecursepatterns = self.config.getini("norecursedirs")
          if any(fnmatch_ex(pat, fspath) for pat in norecursepatterns):
              return False
          return True
  
      def _collectfile(
          self, fspath: Path, handle_dupes: bool = True
      ) -> Sequence[nodes.Collector]:
          assert (
              fspath.is_file()
          ), "{!r} is not a file (isdir={!r}, exists={!r}, islink={!r})".format(
              fspath, fspath.is_dir(), fspath.exists(), fspath.is_symlink()
          )
          ihook = self.gethookproxy(fspath)
          if not self.isinitpath(fspath):
              if ihook.pytest_ignore_collect(fspath=fspath, config=self.config):
                  return ()
  
          if handle_dupes:
              keepduplicates = self.config.getoption("keepduplicates")
              if not keepduplicates:
                  duplicate_paths = self.config.pluginmanager._duplicatepaths
                  if fspath in duplicate_paths:
                      return ()
                  else:
                      duplicate_paths.add(fspath)
  
          return ihook.pytest_collect_file(fspath=fspath, parent=self)  # type: ignore[no-any-return]
  
      @overload
      def perform_collect(
          self, args: Optional[Sequence[str]] = ..., genitems: "Literal[True]" = ...
      ) -> Sequence[nodes.Item]:
          ...
  
      @overload
      def perform_collect(
          self, args: Optional[Sequence[str]] = ..., genitems: bool = ...
      ) -> Sequence[Union[nodes.Item, nodes.Collector]]:
          ...
  
      def perform_collect(
          self, args: Optional[Sequence[str]] = None, genitems: bool = True
      ) -> Sequence[Union[nodes.Item, nodes.Collector]]:
          """Perform the collection phase for this session.
  
          This is called by the default
          :func:`pytest_collection <_pytest.hookspec.pytest_collection>` hook
          implementation; see the documentation of this hook for more details.
          For testing purposes, it may also be called directly on a fresh
          ``Session``.
  
          This function normally recursively expands any collectors collected
          from the session to their items, and only items are returned. For
          testing purposes, this may be suppressed by passing ``genitems=False``,
          in which case the return value contains these collectors unexpanded,
          and ``session.items`` is empty.
          """
          if args is None:
              args = self.config.args
  
          self.trace("perform_collect", self, args)
          self.trace.root.indent += 1
  
          self._notfound: List[Tuple[str, Sequence[nodes.Collector]]] = []
          self._initial_parts: List[Tuple[Path, List[str]]] = []
          self.items: List[nodes.Item] = []
  
          hook = self.config.hook
  
          items: Sequence[Union[nodes.Item, nodes.Collector]] = self.items
          try:
              initialpaths: List[Path] = []
              for arg in args:
                  fspath, parts = resolve_collection_argument(
                      self.config.invocation_params.dir,
                      arg,
                      as_pypath=self.config.option.pyargs,
                  )
                  self._initial_parts.append((fspath, parts))
                  initialpaths.append(fspath)
              self._initialpaths = frozenset(initialpaths)
              rep = collect_one_node(self)
              self.ihook.pytest_collectreport(report=rep)
              self.trace.root.indent -= 1
              if self._notfound:
                  errors = []
                  for arg, cols in self._notfound:
                      line = f"(no name {arg!r} in any of {cols!r})"
                      errors.append(f"not found: {arg}\n{line}")
                  raise UsageError(*errors)
              if not genitems:
                  items = rep.result
              else:
                  if rep.passed:
                      for node in rep.result:
                          self.items.extend(self.genitems(node))
  
              self.config.pluginmanager.check_pending()
              hook.pytest_collection_modifyitems(
                  session=self, config=self.config, items=items
              )
          finally:
              hook.pytest_collection_finish(session=self)
  
          self.testscollected = len(items)
          return items
  
      def collect(self) -> Iterator[Union[nodes.Item, nodes.Collector]]:
          from _pytest.python import Package
  
          # Keep track of any collected nodes in here, so we don't duplicate fixtures.
          node_cache1: Dict[Path, Sequence[nodes.Collector]] = {}
          node_cache2: Dict[Tuple[Type[nodes.Collector], Path], nodes.Collector] = {}
  
          # Keep track of any collected collectors in matchnodes paths, so they
          # are not collected more than once.
          matchnodes_cache: Dict[Tuple[Type[nodes.Collector], str], CollectReport] = {}
  
          # Dirnames of pkgs with dunder-init files.
          pkg_roots: Dict[str, Package] = {}
  
          for argpath, names in self._initial_parts:
              self.trace("processing argument", (argpath, names))
              self.trace.root.indent += 1
  
              # Start with a Session root, and delve to argpath item (dir or file)
              # and stack all Packages found on the way.
              # No point in finding packages when collecting doctests.
              if not self.config.getoption("doctestmodules", False):
                  pm = self.config.pluginmanager
                  confcutdir = pm._confcutdir
                  for parent in (argpath, *argpath.parents):
                      if confcutdir and parent in confcutdir.parents:
                          break
  
                      if parent.is_dir():
                          pkginit = parent / "__init__.py"
                          if pkginit.is_file() and pkginit not in node_cache1:
                              col = self._collectfile(pkginit, handle_dupes=False)
                              if col:
                                  if isinstance(col[0], Package):
                                      pkg_roots[str(parent)] = col[0]
                                  node_cache1[col[0].path] = [col[0]]
  
              # If it's a directory argument, recurse and look for any Subpackages.
              # Let the Package collector deal with subnodes, don't collect here.
              if argpath.is_dir():
                  assert not names, "invalid arg {!r}".format((argpath, names))
  
                  seen_dirs: Set[Path] = set()
                  for direntry in visit(str(argpath), self._recurse):
                      if not direntry.is_file():
                          continue
  
                      path = Path(direntry.path)
                      dirpath = path.parent
  
                      if dirpath not in seen_dirs:
                          # Collect packages first.
                          seen_dirs.add(dirpath)
                          pkginit = dirpath / "__init__.py"
                          if pkginit.exists():
                              for x in self._collectfile(pkginit):
                                  yield x
                                  if isinstance(x, Package):
                                      pkg_roots[str(dirpath)] = x
                      if str(dirpath) in pkg_roots:
                          # Do not collect packages here.
                          continue
  
                      for x in self._collectfile(path):
                          key2 = (type(x), x.path)
                          if key2 in node_cache2:
                              yield node_cache2[key2]
                          else:
                              node_cache2[key2] = x
                              yield x
              else:
                  assert argpath.is_file()
  
                  if argpath in node_cache1:
                      col = node_cache1[argpath]
                  else:
                      collect_root = pkg_roots.get(str(argpath.parent), self)
                      col = collect_root._collectfile(argpath, handle_dupes=False)
                      if col:
                          node_cache1[argpath] = col
  
                  matching = []
                  work: List[
                      Tuple[Sequence[Union[nodes.Item, nodes.Collector]], Sequence[str]]
                  ] = [(col, names)]
                  while work:
                      self.trace("matchnodes", col, names)
                      self.trace.root.indent += 1
  
                      matchnodes, matchnames = work.pop()
                      for node in matchnodes:
                          if not matchnames:
                              matching.append(node)
                              continue
                          if not isinstance(node, nodes.Collector):
                              continue
                          key = (type(node), node.nodeid)
                          if key in matchnodes_cache:
                              rep = matchnodes_cache[key]
                          else:
                              rep = collect_one_node(node)
                              matchnodes_cache[key] = rep
                          if rep.passed:
                              submatchnodes = []
                              for r in rep.result:
                                  # TODO: Remove parametrized workaround once collection structure contains
                                  # parametrization.
                                  if (
                                      r.name == matchnames[0]
                                      or r.name.split("[")[0] == matchnames[0]
                                  ):
                                      submatchnodes.append(r)
                              if submatchnodes:
                                  work.append((submatchnodes, matchnames[1:]))
                              # XXX Accept IDs that don't have "()" for class instances.
                              elif len(rep.result) == 1 and rep.result[0].name == "()":
                                  work.append((rep.result, matchnames))
                          else:
                              # Report collection failures here to avoid failing to run some test
                              # specified in the command line because the module could not be
                              # imported (#134).
                              node.ihook.pytest_collectreport(report=rep)
  
                      self.trace("matchnodes finished -> ", len(matching), "nodes")
                      self.trace.root.indent -= 1
  
                  if not matching:
                      report_arg = "::".join((str(argpath), *names))
                      self._notfound.append((report_arg, col))
                      continue
  
                  # If __init__.py was the only file requested, then the matched
                  # node will be the corresponding Package (by default), and the
                  # first yielded item will be the __init__ Module itself, so
                  # just use that. If this special case isn't taken, then all the
                  # files in the package will be yielded.
                  if argpath.name == "__init__.py" and isinstance(matching[0], Package):
                      try:
                          yield next(iter(matching[0].collect()))
                      except StopIteration:
                          # The package collects nothing with only an __init__.py
                          # file in it, which gets ignored by the default
                          # "python_files" option.
                          pass
                      continue
  
                  yield from matching
  
              self.trace.root.indent -= 1
  
      def genitems(
          self, node: Union[nodes.Item, nodes.Collector]
      ) -> Iterator[nodes.Item]:
          self.trace("genitems", node)
          if isinstance(node, nodes.Item):
              node.ihook.pytest_itemcollected(item=node)
              yield node
          else:
              assert isinstance(node, nodes.Collector)
              rep = collect_one_node(node)
              if rep.passed:
                  for subnode in rep.result:
                      yield from self.genitems(subnode)
              node.ihook.pytest_collectreport(report=rep)
  
  
  def search_pypath(module_name: str) -> str:
      """Search sys.path for the given a dotted module name, and return its file system path."""
      try:
          spec = importlib.util.find_spec(module_name)
      # AttributeError: looks like package module, but actually filename
      # ImportError: module does not exist
      # ValueError: not a module name
      except (AttributeError, ImportError, ValueError):
          return module_name
      if spec is None or spec.origin is None or spec.origin == "namespace":
          return module_name
      elif spec.submodule_search_locations:
          return os.path.dirname(spec.origin)
      else:
          return spec.origin
  
  
  def resolve_collection_argument(
      invocation_path: Path, arg: str, *, as_pypath: bool = False
  ) -> Tuple[Path, List[str]]:
      """Parse path arguments optionally containing selection parts and return (fspath, names).
  
      Command-line arguments can point to files and/or directories, and optionally contain
      parts for specific tests selection, for example:
  
          "pkg/tests/test_foo.py::TestClass::test_foo"
  
      This function ensures the path exists, and returns a tuple:
  
          (Path("/full/path/to/pkg/tests/test_foo.py"), ["TestClass", "test_foo"])
  
      When as_pypath is True, expects that the command-line argument actually contains
      module paths instead of file-system paths:
  
          "pkg.tests.test_foo::TestClass::test_foo"
  
      In which case we search sys.path for a matching module, and then return the *path* to the
      found module.
  
      If the path doesn't exist, raise UsageError.
      If the path is a directory and selection parts are present, raise UsageError.
      """
      strpath, *parts = str(arg).split("::")
      if as_pypath:
          strpath = search_pypath(strpath)
      fspath = invocation_path / strpath
      fspath = absolutepath(fspath)
      if not fspath.exists():
          msg = (
              "module or package not found: {arg} (missing __init__.py?)"
              if as_pypath
              else "file or directory not found: {arg}"
          )
          raise UsageError(msg.format(arg=arg))
      if parts and fspath.is_dir():
          msg = (
              "package argument cannot contain :: selection parts: {arg}"
              if as_pypath
              else "directory argument cannot contain :: selection parts: {arg}"
          )
          raise UsageError(msg.format(arg=arg))
      return fspath, parts
  