intermediate changes

ref:614ed510ddd3cdf86a8c5dbf19afd113397e0172

1 files changed, 514 insertions, 348 deletions

diff --git a/contrib/python/pytest/py3/_pytest/python.py b/contrib/python/pytest/py3/_pytest/python.py
index 0c1df99e36..f1a47d7d33 100644
--- a/contrib/python/pytest/py3/_pytest/python.py
+++ b/contrib/python/pytest/py3/_pytest/python.py
@@ -1,22 +1,29 @@
-""" Python test discovery, setup and run of test functions. """
+"""Python test discovery, setup and run of test functions."""
 import enum
 import fnmatch
 import inspect
 import itertools
 import os
 import sys
-import typing
+import types
 import warnings
 from collections import Counter
 from collections import defaultdict
-from collections.abc import Sequence
 from functools import partial
+from typing import Any
 from typing import Callable
 from typing import Dict
+from typing import Generator
 from typing import Iterable
+from typing import Iterator
 from typing import List
+from typing import Mapping
 from typing import Optional
+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 py
@@ -25,11 +32,13 @@ import _pytest
 from _pytest import fixtures
 from _pytest import nodes
 from _pytest._code import filter_traceback
+from _pytest._code import getfslineno
 from _pytest._code.code import ExceptionInfo
-from _pytest._code.source import getfslineno
+from _pytest._code.code import TerminalRepr
 from _pytest._io import TerminalWriter
 from _pytest._io.saferepr import saferepr
 from _pytest.compat import ascii_escaped
+from _pytest.compat import final
 from _pytest.compat import get_default_arg_names
 from _pytest.compat import get_real_func
 from _pytest.compat import getimfunc
@@ -42,34 +51,33 @@ from _pytest.compat import safe_getattr
 from _pytest.compat import safe_isclass
 from _pytest.compat import STRING_TYPES
 from _pytest.config import Config
+from _pytest.config import ExitCode
 from _pytest.config import hookimpl
-from _pytest.deprecated import FUNCARGNAMES
+from _pytest.config.argparsing import Parser
+from _pytest.deprecated import FSCOLLECTOR_GETHOOKPROXY_ISINITPATH
 from _pytest.fixtures import FuncFixtureInfo
+from _pytest.main import Session
 from _pytest.mark import MARK_GEN
 from _pytest.mark import ParameterSet
 from _pytest.mark.structures import get_unpacked_marks
 from _pytest.mark.structures import Mark
+from _pytest.mark.structures import MarkDecorator
 from _pytest.mark.structures import normalize_mark_list
 from _pytest.outcomes import fail
 from _pytest.outcomes import skip
+from _pytest.pathlib import import_path
+from _pytest.pathlib import ImportPathMismatchError
 from _pytest.pathlib import parts
+from _pytest.pathlib import visit
 from _pytest.warning_types import PytestCollectionWarning
 from _pytest.warning_types import PytestUnhandledCoroutineWarning
 
+if TYPE_CHECKING:
+    from typing_extensions import Literal
+    from _pytest.fixtures import _Scope
 
-def pyobj_property(name):
-    def get(self):
-        node = self.getparent(getattr(__import__("pytest"), name))
-        if node is not None:
-            return node.obj
 
-    doc = "python {} object this node was collected from (can be None).".format(
-        name.lower()
-    )
-    return property(get, None, None, doc)
-
-
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("general")
     group.addoption(
         "--fixtures",
@@ -114,32 +122,24 @@ def pytest_addoption(parser):
         "side effects(use at your own risk)",
     )
 
-    group.addoption(
-        "--import-mode",
-        default="prepend",
-        choices=["prepend", "append"],
-        dest="importmode",
-        help="prepend/append to sys.path when importing test modules, "
-        "default is to prepend.",
-    )
-
 
-def pytest_cmdline_main(config):
+def pytest_cmdline_main(config: Config) -> Optional[Union[int, ExitCode]]:
     if config.option.showfixtures:
         showfixtures(config)
         return 0
     if config.option.show_fixtures_per_test:
         show_fixtures_per_test(config)
         return 0
+    return None
 
 
 def pytest_generate_tests(metafunc: "Metafunc") -> None:
     for marker in metafunc.definition.iter_markers(name="parametrize"):
         # TODO: Fix this type-ignore (overlapping kwargs).
-        metafunc.parametrize(*marker.args, **marker.kwargs, _param_mark=marker)  # type: ignore[misc] # noqa: F821
+        metafunc.parametrize(*marker.args, **marker.kwargs, _param_mark=marker)  # type: ignore[misc]
 
 
-def pytest_configure(config):
+def pytest_configure(config: Config) -> None:
     config.addinivalue_line(
         "markers",
         "parametrize(argnames, argvalues): call a test function multiple "
@@ -148,14 +148,14 @@ def pytest_configure(config):
         "or a list of tuples of values if argnames specifies multiple names. "
         "Example: @parametrize('arg1', [1,2]) would lead to two calls of the "
         "decorated test function, one with arg1=1 and another with arg1=2."
-        "see https://docs.pytest.org/en/latest/parametrize.html for more info "
+        "see https://docs.pytest.org/en/stable/parametrize.html for more info "
         "and examples.",
     )
     config.addinivalue_line(
         "markers",
         "usefixtures(fixturename1, fixturename2, ...): mark tests as needing "
         "all of the specified fixtures. see "
-        "https://docs.pytest.org/en/latest/fixture.html#usefixtures ",
+        "https://docs.pytest.org/en/stable/fixture.html#usefixtures ",
     )
 
 
@@ -164,16 +164,17 @@ def async_warn_and_skip(nodeid: str) -> None:
     msg += (
         "You need to install a suitable plugin for your async framework, for example:\n"
     )
+    msg += "  - anyio\n"
     msg += "  - pytest-asyncio\n"
-    msg += "  - pytest-trio\n"
     msg += "  - pytest-tornasync\n"
+    msg += "  - pytest-trio\n"
     msg += "  - pytest-twisted"
     warnings.warn(PytestUnhandledCoroutineWarning(msg.format(nodeid)))
     skip(msg="async def function and no async plugin installed (see warnings)")
 
 
 @hookimpl(trylast=True)
-def pytest_pyfunc_call(pyfuncitem: "Function"):
+def pytest_pyfunc_call(pyfuncitem: "Function") -> Optional[object]:
     testfunction = pyfuncitem.obj
     if is_async_function(testfunction):
         async_warn_and_skip(pyfuncitem.nodeid)
@@ -185,45 +186,47 @@ def pytest_pyfunc_call(pyfuncitem: "Function"):
     return True
 
 
-def pytest_collect_file(path, parent):
+def pytest_collect_file(
+    path: py.path.local, parent: nodes.Collector
+) -> Optional["Module"]:
     ext = path.ext
     if ext == ".py":
         if not parent.session.isinitpath(path):
             if not path_matches_patterns(
                 path, parent.config.getini("python_files") + ["__init__.py"]
             ):
-                return
+                return None
         ihook = parent.session.gethookproxy(path)
-        return ihook.pytest_pycollect_makemodule(path=path, parent=parent)
+        module: Module = ihook.pytest_pycollect_makemodule(path=path, parent=parent)
+        return module
+    return None
 
 
-def path_matches_patterns(path, patterns):
-    """Returns True if the given py.path.local matches one of the patterns in the list of globs given"""
+def path_matches_patterns(path: py.path.local, patterns: Iterable[str]) -> bool:
+    """Return whether path matches any of the patterns in the list of globs given."""
     return any(path.fnmatch(pattern) for pattern in patterns)
 
 
-def pytest_pycollect_makemodule(path, parent):
+def pytest_pycollect_makemodule(path: py.path.local, parent) -> "Module":
     if path.basename == "__init__.py":
-        return Package.from_parent(parent, fspath=path)
-    return Module.from_parent(parent, fspath=path)
+        pkg: Package = Package.from_parent(parent, fspath=path)
+        return pkg
+    mod: Module = Module.from_parent(parent, fspath=path)
+    return mod
 
 
-@hookimpl(hookwrapper=True)
-def pytest_pycollect_makeitem(collector, name, obj):
-    outcome = yield
-    res = outcome.get_result()
-    if res is not None:
-        return
-    # nothing was collected elsewhere, let's do it here
+@hookimpl(trylast=True)
+def pytest_pycollect_makeitem(collector: "PyCollector", name: str, obj: object):
+    # Nothing was collected elsewhere, let's do it here.
     if safe_isclass(obj):
         if collector.istestclass(obj, name):
-            outcome.force_result(Class.from_parent(collector, name=name, obj=obj))
+            return Class.from_parent(collector, name=name, obj=obj)
     elif collector.istestfunction(obj, name):
-        # mock seems to store unbound methods (issue473), normalize it
+        # mock seems to store unbound methods (issue473), normalize it.
         obj = getattr(obj, "__func__", obj)
         # We need to try and unwrap the function if it's a functools.partial
         # or a functools.wrapped.
-        # We mustn't if it's been wrapped with mock.patch (python 2 only)
+        # We mustn't if it's been wrapped with mock.patch (python 2 only).
         if not (inspect.isfunction(obj) or inspect.isfunction(get_real_func(obj))):
             filename, lineno = getfslineno(obj)
             warnings.warn_explicit(
@@ -244,15 +247,42 @@ def pytest_pycollect_makeitem(collector, name, obj):
                 res.warn(PytestCollectionWarning(reason))
             else:
                 res = list(collector._genfunctions(name, obj))
-            outcome.force_result(res)
+            return res
 
 
 class PyobjMixin:
-    module = pyobj_property("Module")
-    cls = pyobj_property("Class")
-    instance = pyobj_property("Instance")
     _ALLOW_MARKERS = True
 
+    # Function and attributes that the mixin needs (for type-checking only).
+    if TYPE_CHECKING:
+        name: str = ""
+        parent: Optional[nodes.Node] = None
+        own_markers: List[Mark] = []
+
+        def getparent(self, cls: Type[nodes._NodeType]) -> Optional[nodes._NodeType]:
+            ...
+
+        def listchain(self) -> List[nodes.Node]:
+            ...
+
+    @property
+    def module(self):
+        """Python module object this node was collected from (can be None)."""
+        node = self.getparent(Module)
+        return node.obj if node is not None else None
+
+    @property
+    def cls(self):
+        """Python class object this node was collected from (can be None)."""
+        node = self.getparent(Class)
+        return node.obj if node is not None else None
+
+    @property
+    def instance(self):
+        """Python instance object this node was collected from (can be None)."""
+        node = self.getparent(Instance)
+        return node.obj if node is not None else None
+
     @property
     def obj(self):
         """Underlying Python object."""
@@ -270,11 +300,14 @@ class PyobjMixin:
         self._obj = value
 
     def _getobj(self):
-        """Gets the underlying Python object. May be overwritten by subclasses."""
-        return getattr(self.parent.obj, self.name)
-
-    def getmodpath(self, stopatmodule=True, includemodule=False):
-        """ return python path relative to the containing module. """
+        """Get the underlying Python object. May be overwritten by subclasses."""
+        # TODO: Improve the type of `parent` such that assert/ignore aren't needed.
+        assert self.parent is not None
+        obj = self.parent.obj  # type: ignore[attr-defined]
+        return getattr(obj, self.name)
+
+    def getmodpath(self, stopatmodule: bool = True, includemodule: bool = False) -> str:
+        """Return Python path relative to the containing module."""
         chain = self.listchain()
         chain.reverse()
         parts = []
@@ -301,7 +334,7 @@ class PyobjMixin:
             file_path = sys.modules[obj.__module__].__file__
             if file_path.endswith(".pyc"):
                 file_path = file_path[:-1]
-            fspath = file_path  # type: Union[py.path.local, str]
+            fspath: Union[py.path.local, str] = file_path
             lineno = compat_co_firstlineno
         else:
             fspath, lineno = getfslineno(obj)
@@ -310,26 +343,46 @@ class PyobjMixin:
         return fspath, lineno, modpath
 
 
+# As an optimization, these builtin attribute names are pre-ignored when
+# iterating over an object during collection -- the pytest_pycollect_makeitem
+# hook is not called for them.
+# fmt: off
+class _EmptyClass: pass  # noqa: E701
+IGNORED_ATTRIBUTES = frozenset.union(  # noqa: E305
+    frozenset(),
+    # Module.
+    dir(types.ModuleType("empty_module")),
+    # Some extra module attributes the above doesn't catch.
+    {"__builtins__", "__file__", "__cached__"},
+    # Class.
+    dir(_EmptyClass),
+    # Instance.
+    dir(_EmptyClass()),
+)
+del _EmptyClass
+# fmt: on
+
+
 class PyCollector(PyobjMixin, nodes.Collector):
-    def funcnamefilter(self, name):
+    def funcnamefilter(self, name: str) -> bool:
         return self._matches_prefix_or_glob_option("python_functions", name)
 
-    def isnosetest(self, obj):
-        """ Look for the __test__ attribute, which is applied by the
-        @nose.tools.istest decorator
+    def isnosetest(self, obj: object) -> bool:
+        """Look for the __test__ attribute, which is applied by the
+        @nose.tools.istest decorator.
         """
         # We explicitly check for "is True" here to not mistakenly treat
         # classes with a custom __getattr__ returning something truthy (like a
         # function) as test classes.
         return safe_getattr(obj, "__test__", False) is True
 
-    def classnamefilter(self, name):
+    def classnamefilter(self, name: str) -> bool:
         return self._matches_prefix_or_glob_option("python_classes", name)
 
-    def istestfunction(self, obj, name):
+    def istestfunction(self, obj: object, name: str) -> bool:
         if self.funcnamefilter(name) or self.isnosetest(obj):
             if isinstance(obj, staticmethod):
-                # static methods need to be unwrapped
+                # staticmethods need to be unwrapped.
                 obj = safe_getattr(obj, "__func__", False)
             return (
                 safe_getattr(obj, "__call__", False)
@@ -338,48 +391,54 @@ class PyCollector(PyobjMixin, nodes.Collector):
         else:
             return False
 
-    def istestclass(self, obj, name):
+    def istestclass(self, obj: object, name: str) -> bool:
         return self.classnamefilter(name) or self.isnosetest(obj)
 
-    def _matches_prefix_or_glob_option(self, option_name, name):
-        """
-        checks if the given name matches the prefix or glob-pattern defined
-        in ini configuration.
-        """
+    def _matches_prefix_or_glob_option(self, option_name: str, name: str) -> bool:
+        """Check if the given name matches the prefix or glob-pattern defined
+        in ini configuration."""
         for option in self.config.getini(option_name):
             if name.startswith(option):
                 return True
-            # check that name looks like a glob-string before calling fnmatch
+            # Check that name looks like a glob-string before calling fnmatch
             # because this is called for every name in each collected module,
-            # and fnmatch is somewhat expensive to call
+            # and fnmatch is somewhat expensive to call.
             elif ("*" in option or "?" in option or "[" in option) and fnmatch.fnmatch(
                 name, option
             ):
                 return True
         return False
 
-    def collect(self):
+    def collect(self) -> Iterable[Union[nodes.Item, nodes.Collector]]:
         if not getattr(self.obj, "__test__", True):
             return []
 
         # NB. we avoid random getattrs and peek in the __dict__ instead
         # (XXX originally introduced from a PyPy need, still true?)
         dicts = [getattr(self.obj, "__dict__", {})]
-        for basecls in inspect.getmro(self.obj.__class__):
+        for basecls in self.obj.__class__.__mro__:
             dicts.append(basecls.__dict__)
-        seen = {}
-        values = []
+        seen: Set[str] = set()
+        values: List[Union[nodes.Item, nodes.Collector]] = []
+        ihook = self.ihook
         for dic in dicts:
+            # Note: seems like the dict can change during iteration -
+            # be careful not to remove the list() without consideration.
             for name, obj in list(dic.items()):
+                if name in IGNORED_ATTRIBUTES:
+                    continue
                 if name in seen:
                     continue
-                seen[name] = True
-                res = self._makeitem(name, obj)
+                seen.add(name)
+                res = ihook.pytest_pycollect_makeitem(
+                    collector=self, name=name, obj=obj
+                )
                 if res is None:
                     continue
-                if not isinstance(res, list):
-                    res = [res]
-                values.extend(res)
+                elif isinstance(res, list):
+                    values.extend(res)
+                else:
+                    values.append(res)
 
         def sort_key(item):
             fspath, lineno, _ = item.reportinfo()
@@ -388,12 +447,10 @@ class PyCollector(PyobjMixin, nodes.Collector):
         values.sort(key=sort_key)
         return values
 
-    def _makeitem(self, name, obj):
-        # assert self.ihook.fspath == self.fspath, self
-        return self.ihook.pytest_pycollect_makeitem(collector=self, name=name, obj=obj)
-
-    def _genfunctions(self, name, funcobj):
-        module = self.getparent(Module).obj
+    def _genfunctions(self, name: str, funcobj) -> Iterator["Function"]:
+        modulecol = self.getparent(Module)
+        assert modulecol is not None
+        module = modulecol.obj
         clscol = self.getparent(Class)
         cls = clscol and clscol.obj or None
         fm = self.session._fixturemanager
@@ -407,7 +464,7 @@ class PyCollector(PyobjMixin, nodes.Collector):
         methods = []
         if hasattr(module, "pytest_generate_tests"):
             methods.append(module.pytest_generate_tests)
-        if hasattr(cls, "pytest_generate_tests"):
+        if cls is not None and hasattr(cls, "pytest_generate_tests"):
             methods.append(cls().pytest_generate_tests)
 
         self.ihook.pytest_generate_tests.call_extra(methods, dict(metafunc=metafunc))
@@ -415,16 +472,16 @@ class PyCollector(PyobjMixin, nodes.Collector):
         if not metafunc._calls:
             yield Function.from_parent(self, name=name, fixtureinfo=fixtureinfo)
         else:
-            # add funcargs() as fixturedefs to fixtureinfo.arg2fixturedefs
+            # Add funcargs() as fixturedefs to fixtureinfo.arg2fixturedefs.
             fixtures.add_funcarg_pseudo_fixture_def(self, metafunc, fm)
 
-            # add_funcarg_pseudo_fixture_def may have shadowed some fixtures
+            # Add_funcarg_pseudo_fixture_def may have shadowed some fixtures
             # with direct parametrization, so make sure we update what the
             # function really needs.
             fixtureinfo.prune_dependency_tree()
 
             for callspec in metafunc._calls:
-                subname = "{}[{}]".format(name, callspec.id)
+                subname = f"{name}[{callspec.id}]"
                 yield Function.from_parent(
                     self,
                     name=subname,
@@ -437,19 +494,19 @@ class PyCollector(PyobjMixin, nodes.Collector):
 
 
 class Module(nodes.File, PyCollector):
-    """ Collector for test classes and functions. """
+    """Collector for test classes and functions."""
 
     def _getobj(self):
         return self._importtestmodule()
 
-    def collect(self):
+    def collect(self) -> Iterable[Union[nodes.Item, nodes.Collector]]:
         self._inject_setup_module_fixture()
         self._inject_setup_function_fixture()
         self.session._fixturemanager.parsefactories(self)
         return super().collect()
 
-    def _inject_setup_module_fixture(self):
-        """Injects a hidden autouse, module scoped fixture into the collected module object
+    def _inject_setup_module_fixture(self) -> None:
+        """Inject a hidden autouse, module scoped fixture into the collected module object
         that invokes setUpModule/tearDownModule if either or both are available.
 
         Using a fixture to invoke this methods ensures we play nicely and unsurprisingly with
@@ -465,8 +522,13 @@ class Module(nodes.File, PyCollector):
         if setup_module is None and teardown_module is None:
             return
 
-        @fixtures.fixture(autouse=True, scope="module")
-        def xunit_setup_module_fixture(request):
+        @fixtures.fixture(
+            autouse=True,
+            scope="module",
+            # Use a unique name to speed up lookup.
+            name=f"xunit_setup_module_fixture_{self.obj.__name__}",
+        )
+        def xunit_setup_module_fixture(request) -> Generator[None, None, None]:
             if setup_module is not None:
                 _call_with_optional_argument(setup_module, request.module)
             yield
@@ -475,8 +537,8 @@ class Module(nodes.File, PyCollector):
 
         self.obj.__pytest_setup_module = xunit_setup_module_fixture
 
-    def _inject_setup_function_fixture(self):
-        """Injects a hidden autouse, function scoped fixture into the collected module object
+    def _inject_setup_function_fixture(self) -> None:
+        """Inject a hidden autouse, function scoped fixture into the collected module object
         that invokes setup_function/teardown_function if either or both are available.
 
         Using a fixture to invoke this methods ensures we play nicely and unsurprisingly with
@@ -489,8 +551,13 @@ class Module(nodes.File, PyCollector):
         if setup_function is None and teardown_function is None:
             return
 
-        @fixtures.fixture(autouse=True, scope="function")
-        def xunit_setup_function_fixture(request):
+        @fixtures.fixture(
+            autouse=True,
+            scope="function",
+            # Use a unique name to speed up lookup.
+            name=f"xunit_setup_function_fixture_{self.obj.__name__}",
+        )
+        def xunit_setup_function_fixture(request) -> Generator[None, None, None]:
             if request.instance is not None:
                 # in this case we are bound to an instance, so we need to let
                 # setup_method handle this
@@ -505,13 +572,15 @@ class Module(nodes.File, PyCollector):
         self.obj.__pytest_setup_function = xunit_setup_function_fixture
 
     def _importtestmodule(self):
-        # we assume we are only called once per module
+        # We assume we are only called once per module.
         importmode = self.config.getoption("--import-mode")
         try:
-            mod = self.fspath.pyimport(ensuresyspath=importmode)
-        except SyntaxError:
-            raise self.CollectError(ExceptionInfo.from_current().getrepr(style="short"))
-        except self.fspath.ImportMismatchError as e:
+            mod = import_path(self.fspath, mode=importmode)
+        except SyntaxError as e:
+            raise self.CollectError(
+                ExceptionInfo.from_current().getrepr(style="short")
+            ) from e
+        except ImportPathMismatchError as e:
             raise self.CollectError(
                 "import file mismatch:\n"
                 "imported module %r has this __file__ attribute:\n"
@@ -520,8 +589,8 @@ class Module(nodes.File, PyCollector):
                 "  %s\n"
                 "HINT: remove __pycache__ / .pyc files and/or use a "
                 "unique basename for your test file modules" % e.args
-            )
-        except ImportError:
+            ) from e
+        except ImportError as e:
             exc_info = ExceptionInfo.from_current()
             if self.config.getoption("verbose") < 2:
                 exc_info.traceback = exc_info.traceback.filter(filter_traceback)
@@ -536,8 +605,8 @@ class Module(nodes.File, PyCollector):
                 "Hint: make sure your test modules/packages have valid Python names.\n"
                 "Traceback:\n"
                 "{traceback}".format(fspath=self.fspath, traceback=formatted_tb)
-            )
-        except _pytest.runner.Skipped as e:
+            ) from e
+        except skip.Exception as e:
             if e.allow_module_level:
                 raise
             raise self.CollectError(
@@ -545,7 +614,7 @@ class Module(nodes.File, PyCollector):
                 "To decorate a test function, use the @pytest.mark.skip "
                 "or @pytest.mark.skipif decorators instead, and to skip a "
                 "module use `pytestmark = pytest.mark.{skip,skipif}."
-            )
+            ) from e
         self.config.pluginmanager.consider_module(mod)
         return mod
 
@@ -560,18 +629,17 @@ class Package(Module):
         session=None,
         nodeid=None,
     ) -> None:
-        # NOTE: could be just the following, but kept as-is for compat.
+        # NOTE: Could be just the following, but kept as-is for compat.
         # nodes.FSCollector.__init__(self, fspath, parent=parent)
         session = parent.session
         nodes.FSCollector.__init__(
             self, fspath, parent=parent, config=config, session=session, nodeid=nodeid
         )
+        self.name = os.path.basename(str(fspath.dirname))
 
-        self.name = fspath.dirname
-
-    def setup(self):
-        # not using fixtures to call setup_module here because autouse fixtures
-        # from packages are not called automatically (#4085)
+    def setup(self) -> None:
+        # Not using fixtures to call setup_module here because autouse fixtures
+        # from packages are not called automatically (#4085).
         setup_module = _get_first_non_fixture_func(
             self.obj, ("setUpModule", "setup_module")
         )
@@ -586,45 +654,84 @@ class Package(Module):
             self.addfinalizer(func)
 
     def gethookproxy(self, fspath: py.path.local):
-        return super()._gethookproxy(fspath)
+        warnings.warn(FSCOLLECTOR_GETHOOKPROXY_ISINITPATH, stacklevel=2)
+        return self.session.gethookproxy(fspath)
+
+    def isinitpath(self, path: py.path.local) -> bool:
+        warnings.warn(FSCOLLECTOR_GETHOOKPROXY_ISINITPATH, stacklevel=2)
+        return self.session.isinitpath(path)
+
+    def _recurse(self, direntry: "os.DirEntry[str]") -> bool:
+        if direntry.name == "__pycache__":
+            return False
+        path = py.path.local(direntry.path)
+        ihook = self.session.gethookproxy(path.dirpath())
+        if ihook.pytest_ignore_collect(path=path, config=self.config):
+            return False
+        norecursepatterns = self.config.getini("norecursedirs")
+        if any(path.check(fnmatch=pat) for pat in norecursepatterns):
+            return False
+        return True
+
+    def _collectfile(
+        self, path: py.path.local, handle_dupes: bool = True
+    ) -> Sequence[nodes.Collector]:
+        assert (
+            path.isfile()
+        ), "{!r} is not a file (isdir={!r}, exists={!r}, islink={!r})".format(
+            path, path.isdir(), path.exists(), path.islink()
+        )
+        ihook = self.session.gethookproxy(path)
+        if not self.session.isinitpath(path):
+            if ihook.pytest_ignore_collect(path=path, config=self.config):
+                return ()
+
+        if handle_dupes:
+            keepduplicates = self.config.getoption("keepduplicates")
+            if not keepduplicates:
+                duplicate_paths = self.config.pluginmanager._duplicatepaths
+                if path in duplicate_paths:
+                    return ()
+                else:
+                    duplicate_paths.add(path)
 
-    def isinitpath(self, path):
-        return path in self.session._initialpaths
+        return ihook.pytest_collect_file(path=path, parent=self)  # type: ignore[no-any-return]
 
-    def collect(self):
+    def collect(self) -> Iterable[Union[nodes.Item, nodes.Collector]]:
         this_path = self.fspath.dirpath()
         init_module = this_path.join("__init__.py")
         if init_module.check(file=1) and path_matches_patterns(
             init_module, self.config.getini("python_files")
         ):
             yield Module.from_parent(self, fspath=init_module)
-        pkg_prefixes = set()
-        for path in this_path.visit(rec=self._recurse, bf=True, sort=True):
+        pkg_prefixes: Set[py.path.local] = set()
+        for direntry in visit(str(this_path), recurse=self._recurse):
+            path = py.path.local(direntry.path)
+
             # We will visit our own __init__.py file, in which case we skip it.
-            is_file = path.isfile()
-            if is_file:
-                if path.basename == "__init__.py" and path.dirpath() == this_path:
+            if direntry.is_file():
+                if direntry.name == "__init__.py" and path.dirpath() == this_path:
                     continue
 
-            parts_ = parts(path.strpath)
+            parts_ = parts(direntry.path)
             if any(
-                pkg_prefix in parts_ and pkg_prefix.join("__init__.py") != path
+                str(pkg_prefix) in parts_ and pkg_prefix.join("__init__.py") != path
                 for pkg_prefix in pkg_prefixes
             ):
                 continue
 
-            if is_file:
+            if direntry.is_file():
                 yield from self._collectfile(path)
-            elif not path.isdir():
+            elif not direntry.is_dir():
                 # Broken symlink or invalid/missing file.
                 continue
             elif path.join("__init__.py").check(file=1):
                 pkg_prefixes.add(path)
 
 
-def _call_with_optional_argument(func, arg):
+def _call_with_optional_argument(func, arg) -> None:
     """Call the given function with the given argument if func accepts one argument, otherwise
-    calls func without arguments"""
+    calls func without arguments."""
     arg_count = func.__code__.co_argcount
     if inspect.ismethod(func):
         arg_count -= 1
@@ -634,11 +741,9 @@ def _call_with_optional_argument(func, arg):
         func()
 
 
-def _get_first_non_fixture_func(obj, names):
+def _get_first_non_fixture_func(obj: object, names: Iterable[str]):
     """Return the attribute from the given object to be used as a setup/teardown
-    xunit-style function, but only if not marked as a fixture to
-    avoid calling it twice.
-    """
+    xunit-style function, but only if not marked as a fixture to avoid calling it twice."""
     for name in names:
         meth = getattr(obj, name, None)
         if meth is not None and fixtures.getfixturemarker(meth) is None:
@@ -646,19 +751,18 @@ def _get_first_non_fixture_func(obj, names):
 
 
 class Class(PyCollector):
-    """ Collector for test methods. """
+    """Collector for test methods."""
 
     @classmethod
     def from_parent(cls, parent, *, name, obj=None):
-        """
-        The public constructor
-        """
+        """The public constructor."""
         return super().from_parent(name=name, parent=parent)
 
-    def collect(self):
+    def collect(self) -> Iterable[Union[nodes.Item, nodes.Collector]]:
         if not safe_getattr(self.obj, "__test__", True):
             return []
         if hasinit(self.obj):
+            assert self.parent is not None
             self.warn(
                 PytestCollectionWarning(
                     "cannot collect test class %r because it has a "
@@ -668,6 +772,7 @@ class Class(PyCollector):
             )
             return []
         elif hasnew(self.obj):
+            assert self.parent is not None
             self.warn(
                 PytestCollectionWarning(
                     "cannot collect test class %r because it has a "
@@ -682,8 +787,8 @@ class Class(PyCollector):
 
         return [Instance.from_parent(self, name="()")]
 
-    def _inject_setup_class_fixture(self):
-        """Injects a hidden autouse, class scoped fixture into the collected class object
+    def _inject_setup_class_fixture(self) -> None:
+        """Inject a hidden autouse, class scoped fixture into the collected class object
         that invokes setup_class/teardown_class if either or both are available.
 
         Using a fixture to invoke this methods ensures we play nicely and unsurprisingly with
@@ -694,8 +799,13 @@ class Class(PyCollector):
         if setup_class is None and teardown_class is None:
             return
 
-        @fixtures.fixture(autouse=True, scope="class")
-        def xunit_setup_class_fixture(cls):
+        @fixtures.fixture(
+            autouse=True,
+            scope="class",
+            # Use a unique name to speed up lookup.
+            name=f"xunit_setup_class_fixture_{self.obj.__qualname__}",
+        )
+        def xunit_setup_class_fixture(cls) -> Generator[None, None, None]:
             if setup_class is not None:
                 func = getimfunc(setup_class)
                 _call_with_optional_argument(func, self.obj)
@@ -706,8 +816,8 @@ class Class(PyCollector):
 
         self.obj.__pytest_setup_class = xunit_setup_class_fixture
 
-    def _inject_setup_method_fixture(self):
-        """Injects a hidden autouse, function scoped fixture into the collected class object
+    def _inject_setup_method_fixture(self) -> None:
+        """Inject a hidden autouse, function scoped fixture into the collected class object
         that invokes setup_method/teardown_method if either or both are available.
 
         Using a fixture to invoke this methods ensures we play nicely and unsurprisingly with
@@ -718,8 +828,13 @@ class Class(PyCollector):
         if setup_method is None and teardown_method is None:
             return
 
-        @fixtures.fixture(autouse=True, scope="function")
-        def xunit_setup_method_fixture(self, request):
+        @fixtures.fixture(
+            autouse=True,
+            scope="function",
+            # Use a unique name to speed up lookup.
+            name=f"xunit_setup_method_fixture_{self.obj.__qualname__}",
+        )
+        def xunit_setup_method_fixture(self, request) -> Generator[None, None, None]:
             method = request.function
             if setup_method is not None:
                 func = getattr(self, "setup_method")
@@ -734,14 +849,17 @@ class Class(PyCollector):
 
 class Instance(PyCollector):
     _ALLOW_MARKERS = False  # hack, destroy later
-    # instances share the object with their parents in a way
+    # Instances share the object with their parents in a way
     # that duplicates markers instances if not taken out
-    # can be removed at node structure reorganization time
+    # can be removed at node structure reorganization time.
 
     def _getobj(self):
-        return self.parent.obj()
+        # TODO: Improve the type of `parent` such that assert/ignore aren't needed.
+        assert self.parent is not None
+        obj = self.parent.obj  # type: ignore[attr-defined]
+        return obj()
 
-    def collect(self):
+    def collect(self) -> Iterable[Union[nodes.Item, nodes.Collector]]:
         self.session._fixturemanager.parsefactories(self)
         return super().collect()
 
@@ -750,29 +868,33 @@ class Instance(PyCollector):
         return self.obj
 
 
-def hasinit(obj):
-    init = getattr(obj, "__init__", None)
+def hasinit(obj: object) -> bool:
+    init: object = getattr(obj, "__init__", None)
     if init:
         return init != object.__init__
+    return False
 
 
-def hasnew(obj):
-    new = getattr(obj, "__new__", None)
+def hasnew(obj: object) -> bool:
+    new: object = getattr(obj, "__new__", None)
     if new:
         return new != object.__new__
+    return False
 
 
+@final
 class CallSpec2:
-    def __init__(self, metafunc):
+    def __init__(self, metafunc: "Metafunc") -> None:
         self.metafunc = metafunc
-        self.funcargs = {}
-        self._idlist = []
-        self.params = {}
-        self._arg2scopenum = {}  # used for sorting parametrized resources
-        self.marks = []
-        self.indices = {}
-
-    def copy(self):
+        self.funcargs: Dict[str, object] = {}
+        self._idlist: List[str] = []
+        self.params: Dict[str, object] = {}
+        # Used for sorting parametrized resources.
+        self._arg2scopenum: Dict[str, int] = {}
+        self.marks: List[Mark] = []
+        self.indices: Dict[str, int] = {}
+
+    def copy(self) -> "CallSpec2":
         cs = CallSpec2(self.metafunc)
         cs.funcargs.update(self.funcargs)
         cs.params.update(self.params)
@@ -782,34 +904,49 @@ class CallSpec2:
         cs._idlist = list(self._idlist)
         return cs
 
-    def _checkargnotcontained(self, arg):
+    def _checkargnotcontained(self, arg: str) -> None:
         if arg in self.params or arg in self.funcargs:
-            raise ValueError("duplicate {!r}".format(arg))
+            raise ValueError(f"duplicate {arg!r}")
 
-    def getparam(self, name):
+    def getparam(self, name: str) -> object:
         try:
             return self.params[name]
-        except KeyError:
-            raise ValueError(name)
+        except KeyError as e:
+            raise ValueError(name) from e
 
     @property
-    def id(self):
+    def id(self) -> str:
         return "-".join(map(str, self._idlist))
 
-    def setmulti2(self, valtypes, argnames, valset, id, marks, scopenum, param_index):
+    def setmulti2(
+        self,
+        valtypes: Mapping[str, "Literal['params', 'funcargs']"],
+        argnames: Sequence[str],
+        valset: Iterable[object],
+        id: str,
+        marks: Iterable[Union[Mark, MarkDecorator]],
+        scopenum: int,
+        param_index: int,
+    ) -> None:
         for arg, val in zip(argnames, valset):
             self._checkargnotcontained(arg)
             valtype_for_arg = valtypes[arg]
-            getattr(self, valtype_for_arg)[arg] = val
+            if valtype_for_arg == "params":
+                self.params[arg] = val
+            elif valtype_for_arg == "funcargs":
+                self.funcargs[arg] = val
+            else:  # pragma: no cover
+                assert False, f"Unhandled valtype for arg: {valtype_for_arg}"
             self.indices[arg] = param_index
             self._arg2scopenum[arg] = scopenum
         self._idlist.append(id)
         self.marks.extend(normalize_mark_list(marks))
 
 
+@final
 class Metafunc:
-    """
-    Metafunc objects are passed to the :func:`pytest_generate_tests <_pytest.hookspec.pytest_generate_tests>` hook.
+    """Objects passed to the :func:`pytest_generate_tests <_pytest.hookspec.pytest_generate_tests>` hook.
+
     They help to inspect a test function and to generate tests according to
     test configuration or values specified in the class or module where a
     test function is defined.
@@ -823,71 +960,71 @@ class Metafunc:
         cls=None,
         module=None,
     ) -> None:
+        #: Access to the underlying :class:`_pytest.python.FunctionDefinition`.
         self.definition = definition
 
-        #: access to the :class:`_pytest.config.Config` object for the test session
+        #: Access to the :class:`_pytest.config.Config` object for the test session.
         self.config = config
 
-        #: the module object where the test function is defined in.
+        #: The module object where the test function is defined in.
         self.module = module
 
-        #: underlying python test function
+        #: Underlying Python test function.
         self.function = definition.obj
 
-        #: set of fixture names required by the test function
+        #: Set of fixture names required by the test function.
         self.fixturenames = fixtureinfo.names_closure
 
-        #: class object where the test function is defined in or ``None``.
+        #: Class object where the test function is defined in or ``None``.
         self.cls = cls
 
-        self._calls = []  # type: List[CallSpec2]
+        self._calls: List[CallSpec2] = []
         self._arg2fixturedefs = fixtureinfo.name2fixturedefs
 
-    @property
-    def funcargnames(self):
-        """ alias attribute for ``fixturenames`` for pre-2.3 compatibility"""
-        warnings.warn(FUNCARGNAMES, stacklevel=2)
-        return self.fixturenames
-
     def parametrize(
         self,
         argnames: Union[str, List[str], Tuple[str, ...]],
-        argvalues: Iterable[Union[ParameterSet, typing.Sequence[object], object]],
-        indirect: Union[bool, typing.Sequence[str]] = False,
+        argvalues: Iterable[Union[ParameterSet, Sequence[object], object]],
+        indirect: Union[bool, Sequence[str]] = False,
         ids: Optional[
             Union[
                 Iterable[Union[None, str, float, int, bool]],
-                Callable[[object], Optional[object]],
+                Callable[[Any], Optional[object]],
             ]
         ] = None,
-        scope: "Optional[str]" = None,
+        scope: "Optional[_Scope]" = None,
         *,
-        _param_mark: Optional[Mark] = None
+        _param_mark: Optional[Mark] = None,
     ) -> None:
-        """ Add new invocations to the underlying test function using the list
+        """Add new invocations to the underlying test function using the list
         of argvalues for the given argnames.  Parametrization is performed
         during the collection phase.  If you need to setup expensive resources
         see about setting indirect to do it rather at test setup time.
 
-        :arg argnames: a comma-separated string denoting one or more argument
-                       names, or a list/tuple of argument strings.
+        :param argnames:
+            A comma-separated string denoting one or more argument names, or
+            a list/tuple of argument strings.
 
-        :arg argvalues: The list of argvalues determines how often a
-            test is invoked with different argument values.  If only one
-            argname was specified argvalues is a list of values.  If N
-            argnames were specified, argvalues must be a list of N-tuples,
-            where each tuple-element specifies a value for its respective
-            argname.
+        :param argvalues:
+            The list of argvalues determines how often a test is invoked with
+            different argument values.
 
-        :arg indirect: The list of argnames or boolean. A list of arguments'
-            names (subset of argnames). If True the list contains all names from
-            the argnames. Each argvalue corresponding to an argname in this list will
+            If only one argname was specified argvalues is a list of values.
+            If N argnames were specified, argvalues must be a list of
+            N-tuples, where each tuple-element specifies a value for its
+            respective argname.
+
+        :param indirect:
+            A list of arguments' names (subset of argnames) or a boolean.
+            If True the list contains all names from the argnames. Each
+            argvalue corresponding to an argname in this list will
             be passed as request.param to its respective argname fixture
             function so that it can perform more expensive setups during the
             setup phase of a test rather than at collection time.
 
-        :arg ids: sequence of (or generator for) ids for ``argvalues``,
-              or a callable to return part of the id for each argvalue.
+        :param ids:
+            Sequence of (or generator for) ids for ``argvalues``,
+            or a callable to return part of the id for each argvalue.
 
             With sequences (and generators like ``itertools.count()``) the
             returned ids should be of type ``string``, ``int``, ``float``,
@@ -905,7 +1042,8 @@ class Metafunc:
             If no ids are provided they will be generated automatically from
             the argvalues.
 
-        :arg scope: if specified it denotes the scope of the parameters.
+        :param scope:
+            If specified it denotes the scope of the parameters.
             The scope is used for grouping tests by parameter instances.
             It will also override any fixture-function defined scope, allowing
             to set a dynamic scope using test context or configuration.
@@ -917,7 +1055,7 @@ class Metafunc:
             argvalues,
             self.function,
             self.config,
-            function_definition=self.definition,
+            nodeid=self.definition.nodeid,
         )
         del argvalues
 
@@ -940,19 +1078,21 @@ class Metafunc:
             if generated_ids is not None:
                 ids = generated_ids
 
-        ids = self._resolve_arg_ids(argnames, ids, parameters, item=self.definition)
+        ids = self._resolve_arg_ids(
+            argnames, ids, parameters, nodeid=self.definition.nodeid
+        )
 
         # Store used (possibly generated) ids with parametrize Marks.
         if _param_mark and _param_mark._param_ids_from and generated_ids is None:
             object.__setattr__(_param_mark._param_ids_from, "_param_ids_generated", ids)
 
         scopenum = scope2index(
-            scope, descr="parametrize() call in {}".format(self.function.__name__)
+            scope, descr=f"parametrize() call in {self.function.__name__}"
         )
 
-        # create the new calls: if we are parametrize() multiple times (by applying the decorator
+        # Create the new calls: if we are parametrize() multiple times (by applying the decorator
         # more than once) then we accumulate those calls generating the cartesian product
-        # of all calls
+        # of all calls.
         newcalls = []
         for callspec in self._calls or [CallSpec2(self)]:
             for param_index, (param_id, param_set) in enumerate(zip(ids, parameters)):
@@ -971,25 +1111,25 @@ class Metafunc:
 
     def _resolve_arg_ids(
         self,
-        argnames: typing.Sequence[str],
+        argnames: Sequence[str],
         ids: Optional[
             Union[
                 Iterable[Union[None, str, float, int, bool]],
-                Callable[[object], Optional[object]],
+                Callable[[Any], Optional[object]],
             ]
         ],
-        parameters: typing.Sequence[ParameterSet],
-        item,
+        parameters: Sequence[ParameterSet],
+        nodeid: str,
     ) -> List[str]:
-        """Resolves the actual ids for the given argnames, based on the ``ids`` parameter given
+        """Resolve the actual ids for the given argnames, based on the ``ids`` parameter given
         to ``parametrize``.
 
-        :param List[str] argnames: list of argument names passed to ``parametrize()``.
-        :param ids: the ids parameter of the parametrized call (see docs).
-        :param List[ParameterSet] parameters: the list of parameter values, same size as ``argnames``.
-        :param Item item: the item that generated this parametrized call.
+        :param List[str] argnames: List of argument names passed to ``parametrize()``.
+        :param ids: The ids parameter of the parametrized call (see docs).
+        :param List[ParameterSet] parameters: The list of parameter values, same size as ``argnames``.
+        :param str str: The nodeid of the item that generated this parametrized call.
         :rtype: List[str]
-        :return: the list of ids for each argname given
+        :returns: The list of ids for each argname given.
         """
         if ids is None:
             idfn = None
@@ -1000,21 +1140,21 @@ class Metafunc:
         else:
             idfn = None
             ids_ = self._validate_ids(ids, parameters, self.function.__name__)
-        return idmaker(argnames, parameters, idfn, ids_, self.config, item=item)
+        return idmaker(argnames, parameters, idfn, ids_, self.config, nodeid=nodeid)
 
     def _validate_ids(
         self,
         ids: Iterable[Union[None, str, float, int, bool]],
-        parameters: typing.Sequence[ParameterSet],
+        parameters: Sequence[ParameterSet],
         func_name: str,
     ) -> List[Union[None, str]]:
         try:
-            num_ids = len(ids)  # type: ignore[arg-type] # noqa: F821
+            num_ids = len(ids)  # type: ignore[arg-type]
         except TypeError:
             try:
                 iter(ids)
-            except TypeError:
-                raise TypeError("ids must be a callable or an iterable")
+            except TypeError as e:
+                raise TypeError("ids must be a callable or an iterable") from e
             num_ids = len(parameters)
 
         # num_ids == 0 is a special case: https://github.com/pytest-dev/pytest/issues/1849
@@ -1029,7 +1169,10 @@ class Metafunc:
             elif isinstance(id_value, (float, int, bool)):
                 new_ids.append(str(id_value))
             else:
-                msg = "In {}: ids must be list of string/float/int/bool, found: {} (type: {!r}) at index {}"
+                msg = (  # type: ignore[unreachable]
+                    "In {}: ids must be list of string/float/int/bool, "
+                    "found: {} (type: {!r}) at index {}"
+                )
                 fail(
                     msg.format(func_name, saferepr(id_value), type(id_value), idx),
                     pytrace=False,
@@ -1037,22 +1180,23 @@ class Metafunc:
         return new_ids
 
     def _resolve_arg_value_types(
-        self,
-        argnames: typing.Sequence[str],
-        indirect: Union[bool, typing.Sequence[str]],
-    ) -> Dict[str, str]:
-        """Resolves if each parametrized argument must be considered a parameter to a fixture or a "funcarg"
-        to the function, based on the ``indirect`` parameter of the parametrized() call.
-
-        :param List[str] argnames: list of argument names passed to ``parametrize()``.
-        :param indirect: same ``indirect`` parameter of ``parametrize()``.
+        self, argnames: Sequence[str], indirect: Union[bool, Sequence[str]],
+    ) -> Dict[str, "Literal['params', 'funcargs']"]:
+        """Resolve if each parametrized argument must be considered a
+        parameter to a fixture or a "funcarg" to the function, based on the
+        ``indirect`` parameter of the parametrized() call.
+
+        :param List[str] argnames: List of argument names passed to ``parametrize()``.
+        :param indirect: Same as the ``indirect`` parameter of ``parametrize()``.
         :rtype: Dict[str, str]
             A dict mapping each arg name to either:
             * "params" if the argname should be the parameter of a fixture of the same name.
             * "funcargs" if the argname should be a parameter to the parametrized test function.
         """
         if isinstance(indirect, bool):
-            valtypes = dict.fromkeys(argnames, "params" if indirect else "funcargs")
+            valtypes: Dict[str, Literal["params", "funcargs"]] = dict.fromkeys(
+                argnames, "params" if indirect else "funcargs"
+            )
         elif isinstance(indirect, Sequence):
             valtypes = dict.fromkeys(argnames, "funcargs")
             for arg in indirect:
@@ -1074,16 +1218,13 @@ class Metafunc:
         return valtypes
 
     def _validate_if_using_arg_names(
-        self,
-        argnames: typing.Sequence[str],
-        indirect: Union[bool, typing.Sequence[str]],
+        self, argnames: Sequence[str], indirect: Union[bool, Sequence[str]],
     ) -> None:
-        """
-        Check if all argnames are being used, by default values, or directly/indirectly.
+        """Check if all argnames are being used, by default values, or directly/indirectly.
 
-        :param List[str] argnames: list of argument names passed to ``parametrize()``.
-        :param indirect: same ``indirect`` parameter of ``parametrize()``.
-        :raise ValueError: if validation fails.
+        :param List[str] argnames: List of argument names passed to ``parametrize()``.
+        :param indirect: Same as the ``indirect`` parameter of ``parametrize()``.
+        :raises ValueError: If validation fails.
         """
         default_arg_names = set(get_default_arg_names(self.function))
         func_name = self.function.__name__
@@ -1102,12 +1243,16 @@ class Metafunc:
                     else:
                         name = "fixture" if indirect else "argument"
                     fail(
-                        "In {}: function uses no {} '{}'".format(func_name, name, arg),
+                        f"In {func_name}: function uses no {name} '{arg}'",
                         pytrace=False,
                     )
 
 
-def _find_parametrized_scope(argnames, arg2fixturedefs, indirect):
+def _find_parametrized_scope(
+    argnames: Sequence[str],
+    arg2fixturedefs: Mapping[str, Sequence[fixtures.FixtureDef[object]]],
+    indirect: Union[bool, Sequence[str]],
+) -> "fixtures._Scope":
     """Find the most appropriate scope for a parametrized call based on its arguments.
 
     When there's at least one direct argument, always use "function" scope.
@@ -1117,9 +1262,7 @@ def _find_parametrized_scope(argnames, arg2fixturedefs, indirect):
 
     Related to issue #1832, based on code posted by @Kingdread.
     """
-    from _pytest.fixtures import scopes
-
-    if isinstance(indirect, (list, tuple)):
+    if isinstance(indirect, Sequence):
         all_arguments_are_fixtures = len(indirect) == len(argnames)
     else:
         all_arguments_are_fixtures = bool(indirect)
@@ -1132,8 +1275,8 @@ def _find_parametrized_scope(argnames, arg2fixturedefs, indirect):
             if name in argnames
         ]
         if used_scopes:
-            # Takes the most narrow scope from used fixtures
-            for scope in reversed(scopes):
+            # Takes the most narrow scope from used fixtures.
+            for scope in reversed(fixtures.scopes):
                 if scope in used_scopes:
                     return scope
 
@@ -1157,8 +1300,8 @@ def _idval(
     val: object,
     argname: str,
     idx: int,
-    idfn: Optional[Callable[[object], Optional[object]]],
-    item,
+    idfn: Optional[Callable[[Any], Optional[object]]],
+    nodeid: Optional[str],
     config: Optional[Config],
 ) -> str:
     if idfn:
@@ -1167,13 +1310,14 @@ def _idval(
             if generated_id is not None:
                 val = generated_id
         except Exception as e:
-            msg = "{}: error raised while trying to determine id of parameter '{}' at position {}"
-            msg = msg.format(item.nodeid, argname, idx)
+            prefix = f"{nodeid}: " if nodeid is not None else ""
+            msg = "error raised while trying to determine id of parameter '{}' at position {}"
+            msg = prefix + msg.format(argname, idx)
             raise ValueError(msg) from e
     elif config:
-        hook_id = config.hook.pytest_make_parametrize_id(
+        hook_id: Optional[str] = config.hook.pytest_make_parametrize_id(
             config=config, val=val, argname=argname
-        )  # type: Optional[str]
+        )
         if hook_id:
             return hook_id
 
@@ -1183,11 +1327,14 @@ def _idval(
         return str(val)
     elif isinstance(val, REGEX_TYPE):
         return ascii_escaped(val.pattern)
+    elif val is NOTSET:
+        # Fallback to default. Note that NOTSET is an enum.Enum.
+        pass
     elif isinstance(val, enum.Enum):
         return str(val)
     elif isinstance(getattr(val, "__name__", None), str):
-        # name of a class, function, module, etc.
-        name = getattr(val, "__name__")  # type: str
+        # Name of a class, function, module, etc.
+        name: str = getattr(val, "__name__")
         return name
     return str(argname) + str(idx)
 
@@ -1223,17 +1370,17 @@ def _idvalset(
     idx: int,
     parameterset: ParameterSet,
     argnames: Iterable[str],
-    idfn: Optional[Callable[[object], Optional[object]]],
+    idfn: Optional[Callable[[Any], Optional[object]]],
     ids: Optional[List[Union[None, str]]],
-    item,
+    nodeid: Optional[str],
     config: Optional[Config],
-):
+) -> str:
     if parameterset.id is not None:
         return parameterset.id
     id = None if ids is None or idx >= len(ids) else ids[idx]
     if id is None:
         this_id = [
-            _idval(val, argname, idx, idfn, item=item, config=config)
+            _idval(val, argname, idx, idfn, nodeid=nodeid, config=config)
             for val, argname in zip(parameterset.values, argnames)
         ]
         return "-".join(this_id)
@@ -1244,13 +1391,15 @@ def _idvalset(
 def idmaker(
     argnames: Iterable[str],
     parametersets: Iterable[ParameterSet],
-    idfn: Optional[Callable[[object], Optional[object]]] = None,
+    idfn: Optional[Callable[[Any], Optional[object]]] = None,
     ids: Optional[List[Union[None, str]]] = None,
     config: Optional[Config] = None,
-    item=None,
+    nodeid: Optional[str] = None,
 ) -> List[str]:
     resolved_ids = [
-        _idvalset(valindex, parameterset, argnames, idfn, ids, config=config, item=item)
+        _idvalset(
+            valindex, parameterset, argnames, idfn, ids, config=config, nodeid=nodeid
+        )
         for valindex, parameterset in enumerate(parametersets)
     ]
 
@@ -1258,13 +1407,13 @@ def idmaker(
     unique_ids = set(resolved_ids)
     if len(unique_ids) != len(resolved_ids):
 
-        # Record the number of occurrences of each test ID
+        # Record the number of occurrences of each test ID.
         test_id_counts = Counter(resolved_ids)
 
-        # Map the test ID to its next suffix
-        test_id_suffixes = defaultdict(int)  # type: Dict[str, int]
+        # Map the test ID to its next suffix.
+        test_id_suffixes: Dict[str, int] = defaultdict(int)
 
-        # Suffix non-unique IDs to make them unique
+        # Suffix non-unique IDs to make them unique.
         for index, test_id in enumerate(resolved_ids):
             if test_id_counts[test_id] > 1:
                 resolved_ids[index] = "{}{}".format(test_id, test_id_suffixes[test_id])
@@ -1279,7 +1428,7 @@ def show_fixtures_per_test(config):
     return wrap_session(config, _show_fixtures_per_test)
 
 
-def _show_fixtures_per_test(config, session):
+def _show_fixtures_per_test(config: Config, session: Session) -> None:
     import _pytest.config
 
     session.perform_collect()
@@ -1288,16 +1437,16 @@ def _show_fixtures_per_test(config, session):
     verbose = config.getvalue("verbose")
 
     def get_best_relpath(func):
-        loc = getlocation(func, curdir)
-        return curdir.bestrelpath(loc)
+        loc = getlocation(func, str(curdir))
+        return curdir.bestrelpath(py.path.local(loc))
 
-    def write_fixture(fixture_def):
+    def write_fixture(fixture_def: fixtures.FixtureDef[object]) -> None:
         argname = fixture_def.argname
         if verbose <= 0 and argname.startswith("_"):
             return
         if verbose > 0:
             bestrel = get_best_relpath(fixture_def.func)
-            funcargspec = "{} -- {}".format(argname, bestrel)
+            funcargspec = f"{argname} -- {bestrel}"
         else:
             funcargspec = argname
         tw.line(funcargspec, green=True)
@@ -1307,37 +1456,35 @@ def _show_fixtures_per_test(config, session):
         else:
             tw.line("    no docstring available", red=True)
 
-    def write_item(item):
-        try:
-            info = item._fixtureinfo
-        except AttributeError:
-            # doctests items have no _fixtureinfo attribute
-            return
-        if not info.name2fixturedefs:
-            # this test item does not use any fixtures
+    def write_item(item: nodes.Item) -> None:
+        # Not all items have _fixtureinfo attribute.
+        info: Optional[FuncFixtureInfo] = getattr(item, "_fixtureinfo", None)
+        if info is None or not info.name2fixturedefs:
+            # This test item does not use any fixtures.
             return
         tw.line()
-        tw.sep("-", "fixtures used by {}".format(item.name))
-        tw.sep("-", "({})".format(get_best_relpath(item.function)))
-        # dict key not used in loop but needed for sorting
+        tw.sep("-", f"fixtures used by {item.name}")
+        # TODO: Fix this type ignore.
+        tw.sep("-", "({})".format(get_best_relpath(item.function)))  # type: ignore[attr-defined]
+        # dict key not used in loop but needed for sorting.
         for _, fixturedefs in sorted(info.name2fixturedefs.items()):
             assert fixturedefs is not None
             if not fixturedefs:
                 continue
-            # last item is expected to be the one used by the test item
+            # Last item is expected to be the one used by the test item.
             write_fixture(fixturedefs[-1])
 
     for session_item in session.items:
         write_item(session_item)
 
 
-def showfixtures(config):
+def showfixtures(config: Config) -> Union[int, ExitCode]:
     from _pytest.main import wrap_session
 
     return wrap_session(config, _showfixtures_main)
 
 
-def _showfixtures_main(config, session):
+def _showfixtures_main(config: Config, session: Session) -> None:
     import _pytest.config
 
     session.perform_collect()
@@ -1348,14 +1495,14 @@ def _showfixtures_main(config, session):
     fm = session._fixturemanager
 
     available = []
-    seen = set()
+    seen: Set[Tuple[str, str]] = set()
 
     for argname, fixturedefs in fm._arg2fixturedefs.items():
         assert fixturedefs is not None
         if not fixturedefs:
             continue
         for fixturedef in fixturedefs:
-            loc = getlocation(fixturedef.func, curdir)
+            loc = getlocation(fixturedef.func, str(curdir))
             if (fixturedef.argname, loc) in seen:
                 continue
             seen.add((fixturedef.argname, loc))
@@ -1363,7 +1510,7 @@ def _showfixtures_main(config, session):
                 (
                     len(fixturedef.baseid),
                     fixturedef.func.__module__,
-                    curdir.bestrelpath(loc),
+                    curdir.bestrelpath(py.path.local(loc)),
                     fixturedef.argname,
                     fixturedef,
                 )
@@ -1375,7 +1522,7 @@ def _showfixtures_main(config, session):
         if currentmodule != module:
             if not module.startswith("_pytest."):
                 tw.line()
-                tw.sep("-", "fixtures defined from {}".format(module))
+                tw.sep("-", f"fixtures defined from {module}")
                 currentmodule = module
         if verbose <= 0 and argname[0] == "_":
             continue
@@ -1385,46 +1532,80 @@ def _showfixtures_main(config, session):
         if verbose > 0:
             tw.write(" -- %s" % bestrel, yellow=True)
         tw.write("\n")
-        loc = getlocation(fixturedef.func, curdir)
+        loc = getlocation(fixturedef.func, str(curdir))
         doc = inspect.getdoc(fixturedef.func)
         if doc:
             write_docstring(tw, doc)
         else:
-            tw.line("    {}: no docstring available".format(loc), red=True)
+            tw.line(f"    {loc}: no docstring available", red=True)
         tw.line()
 
 
 def write_docstring(tw: TerminalWriter, doc: str, indent: str = "    ") -> None:
     for line in doc.split("\n"):
-        tw.write(indent + line + "\n")
+        tw.line(indent + line)
 
 
 class Function(PyobjMixin, nodes.Item):
-    """ a Function Item is responsible for setting up and executing a
-    Python test function.
+    """An Item responsible for setting up and executing a Python test function.
+
+    param name:
+        The full function name, including any decorations like those
+        added by parametrization (``my_func[my_param]``).
+    param parent:
+        The parent Node.
+    param config:
+        The pytest Config object.
+    param callspec:
+        If given, this is function has been parametrized and the callspec contains
+        meta information about the parametrization.
+    param callobj:
+        If given, the object which will be called when the Function is invoked,
+        otherwise the callobj will be obtained from ``parent`` using ``originalname``.
+    param keywords:
+        Keywords bound to the function object for "-k" matching.
+    param session:
+        The pytest Session object.
+    param fixtureinfo:
+        Fixture information already resolved at this fixture node..
+    param originalname:
+        The attribute name to use for accessing the underlying function object.
+        Defaults to ``name``. Set this if name is different from the original name,
+        for example when it contains decorations like those added by parametrization
+        (``my_func[my_param]``).
     """
 
-    # disable since functions handle it themselves
+    # Disable since functions handle it themselves.
     _ALLOW_MARKERS = False
 
     def __init__(
         self,
-        name,
+        name: str,
         parent,
-        args=None,
-        config=None,
+        config: Optional[Config] = None,
         callspec: Optional[CallSpec2] = None,
         callobj=NOTSET,
         keywords=None,
-        session=None,
+        session: Optional[Session] = None,
         fixtureinfo: Optional[FuncFixtureInfo] = None,
-        originalname=None,
+        originalname: Optional[str] = None,
     ) -> None:
         super().__init__(name, parent, config=config, session=session)
-        self._args = args
+
         if callobj is not NOTSET:
             self.obj = callobj
 
+        #: Original function name, without any decorations (for example
+        #: parametrization adds a ``"[...]"`` suffix to function names), used to access
+        #: the underlying function object from ``parent`` (in case ``callobj`` is not given
+        #: explicitly).
+        #:
+        #: .. versionadded:: 3.0
+        self.originalname = originalname or name
+
+        # Note: when FunctionDefinition is introduced, we should change ``originalname``
+        # to a readonly property that returns FunctionDefinition.name.
+
         self.keywords.update(self.obj.__dict__)
         self.own_markers.extend(get_unpacked_marks(self.obj))
         if callspec:
@@ -1455,63 +1636,46 @@ class Function(PyobjMixin, nodes.Item):
             fixtureinfo = self.session._fixturemanager.getfixtureinfo(
                 self, self.obj, self.cls, funcargs=True
             )
-        self._fixtureinfo = fixtureinfo  # type: FuncFixtureInfo
+        self._fixtureinfo: FuncFixtureInfo = fixtureinfo
         self.fixturenames = fixtureinfo.names_closure
         self._initrequest()
 
-        #: original function name, without any decorations (for example
-        #: parametrization adds a ``"[...]"`` suffix to function names).
-        #:
-        #: .. versionadded:: 3.0
-        self.originalname = originalname
-
     @classmethod
     def from_parent(cls, parent, **kw):  # todo: determine sound type limitations
-        """
-        The public  constructor
-        """
+        """The public constructor."""
         return super().from_parent(parent=parent, **kw)
 
-    def _initrequest(self):
-        self.funcargs = {}
-        self._request = fixtures.FixtureRequest(self)
+    def _initrequest(self) -> None:
+        self.funcargs: Dict[str, object] = {}
+        self._request = fixtures.FixtureRequest(self, _ispytest=True)
 
     @property
     def function(self):
-        "underlying python 'function' object"
+        """Underlying python 'function' object."""
         return getimfunc(self.obj)
 
     def _getobj(self):
-        name = self.name
-        i = name.find("[")  # parametrization
-        if i != -1:
-            name = name[:i]
-        return getattr(self.parent.obj, name)
+        assert self.parent is not None
+        return getattr(self.parent.obj, self.originalname)  # type: ignore[attr-defined]
 
     @property
     def _pyfuncitem(self):
-        "(compatonly) for code expecting pytest-2.2 style request objects"
+        """(compatonly) for code expecting pytest-2.2 style request objects."""
         return self
 
-    @property
-    def funcargnames(self):
-        """ alias attribute for ``fixturenames`` for pre-2.3 compatibility"""
-        warnings.warn(FUNCARGNAMES, stacklevel=2)
-        return self.fixturenames
-
     def runtest(self) -> None:
-        """ execute the underlying test function. """
+        """Execute the underlying test function."""
         self.ihook.pytest_pyfunc_call(pyfuncitem=self)
 
     def setup(self) -> None:
         if isinstance(self.parent, Instance):
             self.parent.newinstance()
             self.obj = self._getobj()
-        fixtures.fillfixtures(self)
+        self._request._fillfixtures()
 
-    def _prunetraceback(self, excinfo: ExceptionInfo) -> None:
+    def _prunetraceback(self, excinfo: ExceptionInfo[BaseException]) -> None:
         if hasattr(self, "_obj") and not self.config.getoption("fulltrace", False):
-            code = _pytest._code.Code(get_real_func(self.obj))
+            code = _pytest._code.Code.from_function(get_real_func(self.obj))
             path, firstlineno = code.path, code.firstlineno
             traceback = excinfo.traceback
             ntraceback = traceback.cut(path=path, firstlineno=firstlineno)
@@ -1524,14 +1688,16 @@ class Function(PyobjMixin, nodes.Item):
 
             excinfo.traceback = ntraceback.filter()
             # issue364: mark all but first and last frames to
-            # only show a single-line message for each frame
+            # only show a single-line message for each frame.
             if self.config.getoption("tbstyle", "auto") == "auto":
                 if len(excinfo.traceback) > 2:
                     for entry in excinfo.traceback[1:-1]:
                         entry.set_repr_style("short")
 
-    def repr_failure(self, excinfo, outerr=None):
-        assert outerr is None, "XXX outerr usage is deprecated"
+    # TODO: Type ignored -- breaks Liskov Substitution.
+    def repr_failure(  # type: ignore[override]
+        self, excinfo: ExceptionInfo[BaseException],
+    ) -> Union[str, TerminalRepr]:
         style = self.config.getoption("tbstyle", "auto")
         if style == "auto":
             style = "long"
@@ -1540,11 +1706,11 @@ class Function(PyobjMixin, nodes.Item):
 
 class FunctionDefinition(Function):
     """
-    internal hack until we get actual definition nodes instead of the
-    crappy metafunc hack
+    This class is a step gap solution until we evolve to have actual function definition nodes
+    and manage to get rid of ``metafunc``.
     """
 
     def runtest(self) -> None:
-        raise RuntimeError("function definitions are not supposed to be used")
+        raise RuntimeError("function definitions are not supposed to be run as tests")
 
     setup = runtest