Type annotate some hookspecs & impls

Annotate some "easy" arguments of hooks that repeat in a lot of internal
plugins.

Not all of the arguments are annotated fully for now.

src/_pytest/assertion/__init__.py

@@ -13,12 +13,13 @@ from _pytest.assertion.rewrite import assertstate_key
 from _pytest.compat import TYPE_CHECKING
 from _pytest.config import Config
 from _pytest.config import hookimpl
+from _pytest.config.argparsing import Parser
 
 if TYPE_CHECKING:
     from _pytest.main import Session
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("debugconfig")
     group.addoption(
         "--assert",
@@ -167,7 +168,7 @@ def pytest_runtest_protocol(item):
     util._reprcompare, util._assertion_pass = saved_assert_hooks
 
 
-def pytest_sessionfinish(session):
+def pytest_sessionfinish(session: "Session") -> None:
     assertstate = session.config._store.get(assertstate_key, None)
     if assertstate:
         if assertstate.hook is not None:

src/_pytest/cacheprovider.py

@@ -11,6 +11,7 @@ from typing import Generator
 from typing import List
 from typing import Optional
 from typing import Set
+from typing import Union
 
 import attr
 import py
@@ -24,6 +25,8 @@ from _pytest import nodes
 from _pytest._io import TerminalWriter
 from _pytest.compat import order_preserving_dict
 from _pytest.config import Config
+from _pytest.config import ExitCode
+from _pytest.config.argparsing import Parser
 from _pytest.main import Session
 from _pytest.python import Module
 
@@ -329,11 +332,12 @@ class LFPlugin:
             else:
                 self._report_status += "not deselecting items."
 
-    def pytest_sessionfinish(self, session):
+    def pytest_sessionfinish(self, session: Session) -> None:
         config = self.config
         if config.getoption("cacheshow") or hasattr(config, "slaveinput"):
             return
 
+        assert config.cache is not None
         saved_lastfailed = config.cache.get("cache/lastfailed", {})
         if saved_lastfailed != self.lastfailed:
             config.cache.set("cache/lastfailed", self.lastfailed)
@@ -382,7 +386,7 @@ class NFPlugin:
         config.cache.set("cache/nodeids", sorted(self.cached_nodeids))
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("general")
     group.addoption(
         "--lf",
@@ -440,16 +444,18 @@ def pytest_addoption(parser):
     )
 
 
-def pytest_cmdline_main(config):
+def pytest_cmdline_main(config: Config) -> Optional[Union[int, ExitCode]]:
     if config.option.cacheshow:
         from _pytest.main import wrap_session
 
         return wrap_session(config, cacheshow)
+    return None
 
 
 @pytest.hookimpl(tryfirst=True)
 def pytest_configure(config: Config) -> None:
-    config.cache = Cache.for_config(config)
+    # Type ignored: pending mechanism to store typed objects scoped to config.
+    config.cache = Cache.for_config(config)  # type: ignore # noqa: F821
     config.pluginmanager.register(LFPlugin(config), "lfplugin")
     config.pluginmanager.register(NFPlugin(config), "nfplugin")
 

src/_pytest/capture.py

@@ -16,6 +16,7 @@ from typing import Tuple
 import pytest
 from _pytest.compat import TYPE_CHECKING
 from _pytest.config import Config
+from _pytest.config.argparsing import Parser
 
 if TYPE_CHECKING:
     from typing_extensions import Literal
@@ -23,7 +24,7 @@ if TYPE_CHECKING:
     _CaptureMethod = Literal["fd", "sys", "no", "tee-sys"]
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("general")
     group._addoption(
         "--capture",

src/_pytest/config/__init__.py

@@ -407,7 +407,7 @@ class PytestPluginManager(PluginManager):
         """Return True if the plugin with the given name is registered."""
         return bool(self.get_plugin(name))
 
-    def pytest_configure(self, config):
+    def pytest_configure(self, config: "Config") -> None:
         # XXX now that the pluginmanager exposes hookimpl(tryfirst...)
         # we should remove tryfirst/trylast as markers
         config.addinivalue_line(
@@ -868,7 +868,9 @@ class Config:
     def get_terminal_writer(self):
         return self.pluginmanager.get_plugin("terminalreporter")._tw
 
-    def pytest_cmdline_parse(self, pluginmanager, args):
+    def pytest_cmdline_parse(
+        self, pluginmanager: PytestPluginManager, args: List[str]
+    ) -> object:
         try:
             self.parse(args)
         except UsageError:

src/_pytest/debugging.py

@@ -4,8 +4,11 @@ import functools
 import sys
 
 from _pytest import outcomes
+from _pytest.config import Config
 from _pytest.config import ConftestImportFailure
 from _pytest.config import hookimpl
+from _pytest.config import PytestPluginManager
+from _pytest.config.argparsing import Parser
 from _pytest.config.exceptions import UsageError
 
 
@@ -20,7 +23,7 @@ def _validate_usepdb_cls(value):
     return (modname, classname)
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("general")
     group._addoption(
         "--pdb",
@@ -44,7 +47,7 @@ def pytest_addoption(parser):
     )
 
 
-def pytest_configure(config):
+def pytest_configure(config: Config) -> None:
     import pdb
 
     if config.getvalue("trace"):
@@ -74,8 +77,8 @@ def pytest_configure(config):
 class pytestPDB:
     """ Pseudo PDB that defers to the real pdb. """
 
-    _pluginmanager = None
+    _pluginmanager = None  # type: PytestPluginManager
-    _config = None
+    _config = None  # type: Config
     _saved = []  # type: list
     _recursive_debug = 0
     _wrapped_pdb_cls = None

src/_pytest/doctest.py

@@ -23,6 +23,7 @@ from _pytest._code.code import TerminalRepr
 from _pytest._io import TerminalWriter
 from _pytest.compat import safe_getattr
 from _pytest.compat import TYPE_CHECKING
+from _pytest.config.argparsing import Parser
 from _pytest.fixtures import FixtureRequest
 from _pytest.outcomes import OutcomeException
 from _pytest.python_api import approx
@@ -52,7 +53,7 @@ RUNNER_CLASS = None
 CHECKER_CLASS = None  # type: Optional[Type[doctest.OutputChecker]]
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     parser.addini(
         "doctest_optionflags",
         "option flags for doctests",
@@ -102,7 +103,7 @@ def pytest_addoption(parser):
     )
 
 
-def pytest_unconfigure():
+def pytest_unconfigure() -> None:
     global RUNNER_CLASS
 
     RUNNER_CLASS = None

src/_pytest/faulthandler.py

@@ -4,13 +4,15 @@ import sys
 from typing import TextIO
 
 import pytest
+from _pytest.config import Config
+from _pytest.config.argparsing import Parser
 from _pytest.store import StoreKey
 
 
 fault_handler_stderr_key = StoreKey[TextIO]()
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     help = (
         "Dump the traceback of all threads if a test takes "
         "more than TIMEOUT seconds to finish."
@@ -18,7 +20,7 @@ def pytest_addoption(parser):
     parser.addini("faulthandler_timeout", help, default=0.0)
 
 
-def pytest_configure(config):
+def pytest_configure(config: Config) -> None:
     import faulthandler
 
     if not faulthandler.is_enabled():
@@ -46,14 +48,14 @@ class FaultHandlerHooks:
     """Implements hooks that will actually install fault handler before tests execute,
     as well as correctly handle pdb and internal errors."""
 
-    def pytest_configure(self, config):
+    def pytest_configure(self, config: Config) -> None:
         import faulthandler
 
         stderr_fd_copy = os.dup(self._get_stderr_fileno())
         config._store[fault_handler_stderr_key] = open(stderr_fd_copy, "w")
         faulthandler.enable(file=config._store[fault_handler_stderr_key])
 
-    def pytest_unconfigure(self, config):
+    def pytest_unconfigure(self, config: Config) -> None:
         import faulthandler
 
         faulthandler.disable()

src/_pytest/fixtures.py

@@ -29,6 +29,7 @@ from _pytest.compat import NOTSET
 from _pytest.compat import order_preserving_dict
 from _pytest.compat import safe_getattr
 from _pytest.compat import TYPE_CHECKING
+from _pytest.config.argparsing import Parser
 from _pytest.deprecated import FILLFUNCARGS
 from _pytest.deprecated import FIXTURE_POSITIONAL_ARGUMENTS
 from _pytest.deprecated import FUNCARGNAMES
@@ -49,7 +50,7 @@ class PseudoFixtureDef:
     scope = attr.ib()
 
 
-def pytest_sessionstart(session: "Session"):
+def pytest_sessionstart(session: "Session") -> None:
     import _pytest.python
     import _pytest.nodes
 
@@ -1202,7 +1203,7 @@ def pytestconfig(request):
     return request.config
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     parser.addini(
         "usefixtures",
         type="args",

src/_pytest/helpconfig.py

@@ -2,11 +2,16 @@
 import os
 import sys
 from argparse import Action
+from typing import Optional
+from typing import Union
 
 import py
 
 import pytest
+from _pytest.config import Config
+from _pytest.config import ExitCode
 from _pytest.config import PrintHelp
+from _pytest.config.argparsing import Parser
 
 
 class HelpAction(Action):
@@ -36,7 +41,7 @@ class HelpAction(Action):
             raise PrintHelp
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("debugconfig")
     group.addoption(
         "--version",
@@ -109,7 +114,7 @@ def pytest_cmdline_parse():
         undo_tracing = config.pluginmanager.enable_tracing()
         sys.stderr.write("writing pytestdebug information to %s\n" % path)
 
-        def unset_tracing():
+        def unset_tracing() -> None:
             debugfile.close()
             sys.stderr.write("wrote pytestdebug information to %s\n" % debugfile.name)
             config.trace.root.setwriter(None)
@@ -133,7 +138,7 @@ def showversion(config):
         sys.stderr.write("pytest {}\n".format(pytest.__version__))
 
 
-def pytest_cmdline_main(config):
+def pytest_cmdline_main(config: Config) -> Optional[Union[int, ExitCode]]:
     if config.option.version > 0:
         showversion(config)
         return 0
@@ -142,9 +147,10 @@ def pytest_cmdline_main(config):
         showhelp(config)
         config._ensure_unconfigure()
         return 0
+    return None
 
 
-def showhelp(config):
+def showhelp(config: Config) -> None:
     import textwrap
 
     reporter = config.pluginmanager.get_plugin("terminalreporter")

src/_pytest/hookspec.py

@@ -1,5 +1,6 @@
 """ hook specifications for pytest plugins, invoked from main.py and builtin plugins.  """
 from typing import Any
+from typing import List
 from typing import Mapping
 from typing import Optional
 from typing import Tuple
@@ -14,10 +15,14 @@ from _pytest.compat import TYPE_CHECKING
 if TYPE_CHECKING:
     import warnings
     from _pytest.config import Config
+    from _pytest.config import ExitCode
+    from _pytest.config import PytestPluginManager
+    from _pytest.config import _PluggyPlugin
+    from _pytest.config.argparsing import Parser
     from _pytest.main import Session
+    from _pytest.python import Metafunc
     from _pytest.reports import BaseReport
 
-
 hookspec = HookspecMarker("pytest")
 
 # -------------------------------------------------------------------------
@@ -26,7 +31,7 @@ hookspec = HookspecMarker("pytest")
 
 
 @hookspec(historic=True)
-def pytest_addhooks(pluginmanager):
+def pytest_addhooks(pluginmanager: "PytestPluginManager") -> None:
     """called at plugin registration time to allow adding new hooks via a call to
     ``pluginmanager.add_hookspecs(module_or_class, prefix)``.
 
@@ -39,7 +44,9 @@ def pytest_addhooks(pluginmanager):
 
 
 @hookspec(historic=True)
-def pytest_plugin_registered(plugin, manager):
+def pytest_plugin_registered(
+    plugin: "_PluggyPlugin", manager: "PytestPluginManager"
+) -> None:
     """ a new pytest plugin got registered.
 
     :param plugin: the plugin module or instance
@@ -51,7 +58,7 @@ def pytest_plugin_registered(plugin, manager):
 
 
 @hookspec(historic=True)
-def pytest_addoption(parser, pluginmanager):
+def pytest_addoption(parser: "Parser", pluginmanager: "PytestPluginManager") -> None:
     """register argparse-style options and ini-style config values,
     called once at the beginning of a test run.
 
@@ -89,7 +96,7 @@ def pytest_addoption(parser, pluginmanager):
 
 
 @hookspec(historic=True)
-def pytest_configure(config):
+def pytest_configure(config: "Config") -> None:
     """
     Allows plugins and conftest files to perform initial configuration.
 
@@ -113,7 +120,9 @@ def pytest_configure(config):
 
 
 @hookspec(firstresult=True)
-def pytest_cmdline_parse(pluginmanager, args):
+def pytest_cmdline_parse(
+    pluginmanager: "PytestPluginManager", args: List[str]
+) -> Optional[object]:
     """return initialized config object, parsing the specified args.
 
     Stops at first non-None result, see :ref:`firstresult`
@@ -127,7 +136,7 @@ def pytest_cmdline_parse(pluginmanager, args):
     """
 
 
-def pytest_cmdline_preparse(config, args):
+def pytest_cmdline_preparse(config: "Config", args: List[str]) -> None:
     """(**Deprecated**) modify command line arguments before option parsing.
 
     This hook is considered deprecated and will be removed in a future pytest version. Consider
@@ -142,7 +151,7 @@ def pytest_cmdline_preparse(config, args):
 
 
 @hookspec(firstresult=True)
-def pytest_cmdline_main(config):
+def pytest_cmdline_main(config: "Config") -> "Optional[Union[ExitCode, int]]":
     """ called for performing the main command line action. The default
     implementation will invoke the configure hooks and runtest_mainloop.
 
@@ -155,7 +164,9 @@ def pytest_cmdline_main(config):
     """
 
 
-def pytest_load_initial_conftests(early_config, parser, args):
+def pytest_load_initial_conftests(
+    early_config: "Config", parser: "Parser", args: List[str]
+) -> None:
     """ implements the loading of initial conftest files ahead
     of command line option parsing.
 
@@ -198,7 +209,7 @@ def pytest_collection(session: "Session") -> Optional[Any]:
     """
 
 
-def pytest_collection_modifyitems(session, config, items):
+def pytest_collection_modifyitems(session: "Session", config: "Config", items):
     """ called after collection has been performed, may filter or re-order
     the items in-place.
 
@@ -208,7 +219,7 @@ def pytest_collection_modifyitems(session, config, items):
     """
 
 
-def pytest_collection_finish(session):
+def pytest_collection_finish(session: "Session"):
     """ called after collection has been performed and modified.
 
     :param _pytest.main.Session session: the pytest session object
@@ -216,7 +227,7 @@ def pytest_collection_finish(session):
 
 
 @hookspec(firstresult=True)
-def pytest_ignore_collect(path, config):
+def pytest_ignore_collect(path, config: "Config"):
     """ return True to prevent considering this path for collection.
     This hook is consulted for all files and directories prior to calling
     more specific hooks.
@@ -304,12 +315,12 @@ def pytest_pyfunc_call(pyfuncitem):
     Stops at first non-None result, see :ref:`firstresult` """
 
 
-def pytest_generate_tests(metafunc):
+def pytest_generate_tests(metafunc: "Metafunc") -> None:
     """ generate (multiple) parametrized calls to a test function."""
 
 
 @hookspec(firstresult=True)
-def pytest_make_parametrize_id(config, val, argname):
+def pytest_make_parametrize_id(config: "Config", val, argname) -> Optional[str]:
     """Return a user-friendly string representation of the given ``val`` that will be used
     by @pytest.mark.parametrize calls. Return None if the hook doesn't know about ``val``.
     The parameter name is available as ``argname``, if required.
@@ -328,7 +339,7 @@ def pytest_make_parametrize_id(config, val, argname):
 
 
 @hookspec(firstresult=True)
-def pytest_runtestloop(session):
+def pytest_runtestloop(session: "Session"):
     """ called for performing the main runtest loop
     (after collection finished).
 
@@ -411,7 +422,7 @@ def pytest_runtest_logreport(report):
 
 
 @hookspec(firstresult=True)
-def pytest_report_to_serializable(config, report):
+def pytest_report_to_serializable(config: "Config", report):
     """
     Serializes the given report object into a data structure suitable for sending
     over the wire, e.g. converted to JSON.
@@ -419,7 +430,7 @@ def pytest_report_to_serializable(config, report):
 
 
 @hookspec(firstresult=True)
-def pytest_report_from_serializable(config, data):
+def pytest_report_from_serializable(config: "Config", data):
     """
     Restores a report object previously serialized with pytest_report_to_serializable().
     """
@@ -456,7 +467,7 @@ def pytest_fixture_post_finalizer(fixturedef, request):
 # -------------------------------------------------------------------------
 
 
-def pytest_sessionstart(session):
+def pytest_sessionstart(session: "Session") -> None:
     """ called after the ``Session`` object has been created and before performing collection
     and entering the run test loop.
 
@@ -464,7 +475,9 @@ def pytest_sessionstart(session):
     """
 
 
-def pytest_sessionfinish(session, exitstatus):
+def pytest_sessionfinish(
+    session: "Session", exitstatus: "Union[int, ExitCode]"
+) -> None:
     """ called after whole test run finished, right before returning the exit status to the system.
 
     :param _pytest.main.Session session: the pytest session object
@@ -472,7 +485,7 @@ def pytest_sessionfinish(session, exitstatus):
     """
 
 
-def pytest_unconfigure(config):
+def pytest_unconfigure(config: "Config") -> None:
     """ called before test process is exited.
 
     :param _pytest.config.Config config: pytest config object
@@ -484,7 +497,7 @@ def pytest_unconfigure(config):
 # -------------------------------------------------------------------------
 
 
-def pytest_assertrepr_compare(config, op, left, right):
+def pytest_assertrepr_compare(config: "Config", op, left, right):
     """return explanation for comparisons in failing assert expressions.
 
     Return None for no custom explanation, otherwise return a list
@@ -539,7 +552,7 @@ def pytest_assertion_pass(item, lineno, orig, expl):
 # -------------------------------------------------------------------------
 
 
-def pytest_report_header(config, startdir):
+def pytest_report_header(config: "Config", startdir):
     """ return a string or list of strings to be displayed as header info for terminal reporting.
 
     :param _pytest.config.Config config: pytest config object
@@ -560,7 +573,7 @@ def pytest_report_header(config, startdir):
     """
 
 
-def pytest_report_collectionfinish(config, startdir, items):
+def pytest_report_collectionfinish(config: "Config", startdir, items):
     """
     .. versionadded:: 3.2
 
@@ -610,7 +623,7 @@ def pytest_report_teststatus(
     """
 
 
-def pytest_terminal_summary(terminalreporter, exitstatus, config):
+def pytest_terminal_summary(terminalreporter, exitstatus, config: "Config"):
     """Add a section to terminal summary reporting.
 
     :param _pytest.terminal.TerminalReporter terminalreporter: the internal terminal reporter object
@@ -723,7 +736,7 @@ def pytest_exception_interact(node, call, report):
     """
 
 
-def pytest_enter_pdb(config, pdb):
+def pytest_enter_pdb(config: "Config", pdb):
     """ called upon pdb.set_trace(), can be used by plugins to take special
     action just before the python debugger enters in interactive mode.
 
@@ -732,7 +745,7 @@ def pytest_enter_pdb(config, pdb):
     """
 
 
-def pytest_leave_pdb(config, pdb):
+def pytest_leave_pdb(config: "Config", pdb):
     """ called when leaving pdb (e.g. with continue after pdb.set_trace()).
 
     Can be used by plugins to take special action just after the python

src/_pytest/junitxml.py

@@ -21,7 +21,9 @@ import pytest
 from _pytest import deprecated
 from _pytest import nodes
 from _pytest import timing
+from _pytest.config import Config
 from _pytest.config import filename_arg
+from _pytest.config.argparsing import Parser
 from _pytest.store import StoreKey
 from _pytest.warnings import _issue_warning_captured
 
@@ -361,7 +363,7 @@ def record_testsuite_property(request):
     return record_func
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("terminal reporting")
     group.addoption(
         "--junitxml",
@@ -406,7 +408,7 @@ def pytest_addoption(parser):
     )
 
 
-def pytest_configure(config):
+def pytest_configure(config: Config) -> None:
     xmlpath = config.option.xmlpath
     # prevent opening xmllog on slave nodes (xdist)
     if xmlpath and not hasattr(config, "slaveinput"):
@@ -426,7 +428,7 @@ def pytest_configure(config):
         config.pluginmanager.register(config._store[xml_key])
 
 
-def pytest_unconfigure(config):
+def pytest_unconfigure(config: Config) -> None:
     xml = config._store.get(xml_key, None)
     if xml:
         del config._store[xml_key]
@@ -624,10 +626,10 @@ class LogXML:
         reporter.attrs.update(classname="pytest", name="internal")
         reporter._add_simple(Junit.error, "internal error", excrepr)
 
-    def pytest_sessionstart(self):
+    def pytest_sessionstart(self) -> None:
         self.suite_start_time = timing.time()
 
-    def pytest_sessionfinish(self):
+    def pytest_sessionfinish(self) -> None:
         dirname = os.path.dirname(os.path.abspath(self.logfile))
         if not os.path.isdir(dirname):
             os.makedirs(dirname)

src/_pytest/logging.py

@@ -19,6 +19,7 @@ from _pytest.compat import nullcontext
 from _pytest.config import _strtobool
 from _pytest.config import Config
 from _pytest.config import create_terminal_writer
+from _pytest.config.argparsing import Parser
 from _pytest.pathlib import Path
 from _pytest.store import StoreKey
 
@@ -180,7 +181,7 @@ def get_option_ini(config, *names):
             return ret
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     """Add options to control log capturing."""
     group = parser.getgroup("logging")
 
@@ -478,7 +479,7 @@ def get_log_level_for_setting(config: Config, *setting_names: str) -> Optional[i
 
 # run after terminalreporter/capturemanager are configured
 @pytest.hookimpl(trylast=True)
-def pytest_configure(config):
+def pytest_configure(config: Config) -> None:
     config.pluginmanager.register(LoggingPlugin(config), "logging-plugin")
 
 
@@ -601,7 +602,7 @@ class LoggingPlugin:
         return True
 
     @pytest.hookimpl(hookwrapper=True, tryfirst=True)
-    def pytest_sessionstart(self):
+    def pytest_sessionstart(self) -> Generator[None, None, None]:
         self.log_cli_handler.set_when("sessionstart")
 
         with catching_logs(self.log_cli_handler, level=self.log_cli_level):
@@ -679,7 +680,7 @@ class LoggingPlugin:
         self.log_cli_handler.set_when("finish")
 
     @pytest.hookimpl(hookwrapper=True, tryfirst=True)
-    def pytest_sessionfinish(self):
+    def pytest_sessionfinish(self) -> Generator[None, None, None]:
         self.log_cli_handler.set_when("sessionfinish")
 
         with catching_logs(self.log_cli_handler, level=self.log_cli_level):
@@ -687,7 +688,7 @@ class LoggingPlugin:
                 yield
 
     @pytest.hookimpl
-    def pytest_unconfigure(self):
+    def pytest_unconfigure(self) -> None:
         # Close the FileHandler explicitly.
         # (logging.shutdown might have lost the weakref?!)
         self.log_file_handler.close()

src/_pytest/mark/__init__.py

@@ -18,8 +18,10 @@ from .structures import MarkGenerator
 from .structures import ParameterSet
 from _pytest.compat import TYPE_CHECKING
 from _pytest.config import Config
+from _pytest.config import ExitCode
 from _pytest.config import hookimpl
 from _pytest.config import UsageError
+from _pytest.config.argparsing import Parser
 from _pytest.deprecated import MINUS_K_COLON
 from _pytest.deprecated import MINUS_K_DASH
 from _pytest.store import StoreKey
@@ -27,6 +29,7 @@ from _pytest.store import StoreKey
 if TYPE_CHECKING:
     from _pytest.nodes import Item
 
+
 __all__ = ["Mark", "MarkDecorator", "MarkGenerator", "get_empty_parameterset_mark"]
 
 
@@ -57,7 +60,7 @@ def param(
     return ParameterSet.param(*values, marks=marks, id=id)
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("general")
     group._addoption(
         "-k",
@@ -100,7 +103,7 @@ def pytest_addoption(parser):
 
 
 @hookimpl(tryfirst=True)
-def pytest_cmdline_main(config):
+def pytest_cmdline_main(config: Config) -> Optional[Union[int, ExitCode]]:
     import _pytest.config
 
     if config.option.markers:
@@ -116,6 +119,8 @@ def pytest_cmdline_main(config):
         config._ensure_unconfigure()
         return 0
 
+    return None
+
 
 @attr.s(slots=True)
 class KeywordMatcher:
@@ -254,7 +259,7 @@ def pytest_collection_modifyitems(items, config: Config) -> None:
     deselect_by_mark(items, config)
 
 
-def pytest_configure(config):
+def pytest_configure(config: Config) -> None:
     config._store[old_mark_config_key] = MARK_GEN._config
     MARK_GEN._config = config
 
@@ -267,5 +272,5 @@ def pytest_configure(config):
         )
 
 
-def pytest_unconfigure(config):
+def pytest_unconfigure(config: Config) -> None:
     MARK_GEN._config = config._store.get(old_mark_config_key, None)

src/_pytest/mark/structures.py

@@ -374,7 +374,7 @@ class MarkGenerator:
     applies a 'slowtest' :class:`Mark` on ``test_function``.
     """
 
-    _config = None
+    _config = None  # type: Optional[Config]
     _markers = set()  # type: Set[str]
 
     def __getattr__(self, name: str) -> MarkDecorator:

src/_pytest/nodes.py

@@ -123,7 +123,7 @@ class Node(metaclass=NodeMeta):
 
         #: the pytest config object
         if config:
-            self.config = config
+            self.config = config  # type: Config
         else:
             if not parent:
                 raise TypeError("config or parent must be provided")

src/_pytest/pastebin.py

@@ -4,13 +4,15 @@ from io import StringIO
 from typing import IO
 
 import pytest
+from _pytest.config import Config
+from _pytest.config.argparsing import Parser
 from _pytest.store import StoreKey
 
 
 pastebinfile_key = StoreKey[IO[bytes]]()
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("terminal reporting")
     group._addoption(
         "--pastebin",
@@ -24,7 +26,7 @@ def pytest_addoption(parser):
 
 
 @pytest.hookimpl(trylast=True)
-def pytest_configure(config):
+def pytest_configure(config: Config) -> None:
     if config.option.pastebin == "all":
         tr = config.pluginmanager.getplugin("terminalreporter")
         # if no terminal reporter plugin is present, nothing we can do here;
@@ -44,7 +46,7 @@ def pytest_configure(config):
             tr._tw.write = tee_write
 
 
-def pytest_unconfigure(config):
+def pytest_unconfigure(config: Config) -> None:
     if pastebinfile_key in config._store:
         pastebinfile = config._store[pastebinfile_key]
         # get terminal contents and delete file

src/_pytest/pytester.py

@@ -31,6 +31,7 @@ from _pytest.compat import TYPE_CHECKING
 from _pytest.config import _PluggyPlugin
 from _pytest.config import Config
 from _pytest.config import ExitCode
+from _pytest.config.argparsing import Parser
 from _pytest.fixtures import FixtureRequest
 from _pytest.main import Session
 from _pytest.monkeypatch import MonkeyPatch
@@ -53,7 +54,7 @@ IGNORE_PAM = [  # filenames added when obtaining details about the current user
 ]
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     parser.addoption(
         "--lsof",
         action="store_true",
@@ -78,7 +79,7 @@ def pytest_addoption(parser):
     )
 
 
-def pytest_configure(config):
+def pytest_configure(config: Config) -> None:
     if config.getvalue("lsof"):
         checker = LsofFdLeakChecker()
         if checker.matching_platform():
@@ -938,7 +939,7 @@ class Testdir:
             rec = []
 
             class Collect:
-                def pytest_configure(x, config):
+                def pytest_configure(x, config: Config) -> None:
                     rec.append(self.make_hook_recorder(config.pluginmanager))
 
             plugins.append(Collect())

src/_pytest/python.py

@@ -16,6 +16,7 @@ from typing import Dict
 from typing import Iterable
 from typing import List
 from typing import Optional
+from typing import Set
 from typing import Tuple
 from typing import Union
 
@@ -42,9 +43,12 @@ 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.config.argparsing import Parser
 from _pytest.deprecated import FUNCARGNAMES
 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
@@ -57,7 +61,7 @@ from _pytest.warning_types import PytestCollectionWarning
 from _pytest.warning_types import PytestUnhandledCoroutineWarning
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("general")
     group.addoption(
         "--fixtures",
@@ -112,13 +116,14 @@ def pytest_addoption(parser):
     )
 
 
-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:
@@ -127,7 +132,7 @@ def pytest_generate_tests(metafunc: "Metafunc") -> None:
         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 "
@@ -1308,13 +1313,13 @@ def _show_fixtures_per_test(config, session):
         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()
@@ -1325,7 +1330,7 @@ def _showfixtures_main(config, session):
     fm = session._fixturemanager
 
     available = []
-    seen = set()
+    seen = set()  # type: Set[Tuple[str, str]]
 
     for argname, fixturedefs in fm._arg2fixturedefs.items():
         assert fixturedefs is not None

src/_pytest/resultlog.py

@@ -5,13 +5,15 @@ import os
 
 import py
 
+from _pytest.config import Config
+from _pytest.config.argparsing import Parser
 from _pytest.store import StoreKey
 
 
 resultlog_key = StoreKey["ResultLog"]()
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("terminal reporting", "resultlog plugin options")
     group.addoption(
         "--resultlog",
@@ -23,7 +25,7 @@ def pytest_addoption(parser):
     )
 
 
-def pytest_configure(config):
+def pytest_configure(config: Config) -> None:
     resultlog = config.option.resultlog
     # prevent opening resultlog on slave nodes (xdist)
     if resultlog and not hasattr(config, "slaveinput"):
@@ -40,7 +42,7 @@ def pytest_configure(config):
         _issue_warning_captured(RESULT_LOG, config.hook, stacklevel=2)
 
 
-def pytest_unconfigure(config):
+def pytest_unconfigure(config: Config) -> None:
     resultlog = config._store.get(resultlog_key, None)
     if resultlog:
         resultlog.logfile.close()

src/_pytest/runner.py

@@ -17,6 +17,7 @@ from _pytest import timing
 from _pytest._code.code import ExceptionChainRepr
 from _pytest._code.code import ExceptionInfo
 from _pytest.compat import TYPE_CHECKING
+from _pytest.config.argparsing import Parser
 from _pytest.nodes import Collector
 from _pytest.nodes import Node
 from _pytest.outcomes import Exit
@@ -27,11 +28,13 @@ if TYPE_CHECKING:
     from typing import Type
     from typing_extensions import Literal
 
+    from _pytest.main import Session
+
 #
 # pytest plugin hooks
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("terminal reporting", "reporting", after="general")
     group.addoption(
         "--durations",
@@ -75,11 +78,11 @@ def pytest_terminal_summary(terminalreporter):
         tr.write_line("{:02.2f}s {:<8} {}".format(rep.duration, rep.when, rep.nodeid))
 
 
-def pytest_sessionstart(session):
+def pytest_sessionstart(session: "Session") -> None:
     session._setupstate = SetupState()
 
 
-def pytest_sessionfinish(session):
+def pytest_sessionfinish(session: "Session") -> None:
     session._setupstate.teardown_all()
 
 

src/_pytest/setuponly.py

@@ -1,8 +1,14 @@
+from typing import Optional
+from typing import Union
+
 import pytest
 from _pytest._io.saferepr import saferepr
+from _pytest.config import Config
+from _pytest.config import ExitCode
+from _pytest.config.argparsing import Parser
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("debugconfig")
     group.addoption(
         "--setuponly",
@@ -76,6 +82,7 @@ def _show_fixture_action(fixturedef, msg):
 
 
 @pytest.hookimpl(tryfirst=True)
-def pytest_cmdline_main(config):
+def pytest_cmdline_main(config: Config) -> Optional[Union[int, ExitCode]]:
     if config.option.setuponly:
         config.option.setupshow = True
+    return None

src/_pytest/setupplan.py

@@ -1,7 +1,13 @@
+from typing import Optional
+from typing import Union
+
 import pytest
+from _pytest.config import Config
+from _pytest.config import ExitCode
+from _pytest.config.argparsing import Parser
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("debugconfig")
     group.addoption(
         "--setupplan",
@@ -19,10 +25,12 @@ def pytest_fixture_setup(fixturedef, request):
         my_cache_key = fixturedef.cache_key(request)
         fixturedef.cached_result = (None, my_cache_key, None)
         return fixturedef.cached_result
+    return None
 
 
 @pytest.hookimpl(tryfirst=True)
-def pytest_cmdline_main(config):
+def pytest_cmdline_main(config: Config) -> Optional[Union[int, ExitCode]]:
     if config.option.setupplan:
         config.option.setuponly = True
         config.option.setupshow = True
+    return None

src/_pytest/skipping.py

@@ -1,5 +1,7 @@
 """ support for skip/xfail functions and markers. """
+from _pytest.config import Config
 from _pytest.config import hookimpl
+from _pytest.config.argparsing import Parser
 from _pytest.mark.evaluate import MarkEvaluator
 from _pytest.outcomes import fail
 from _pytest.outcomes import skip
@@ -12,7 +14,7 @@ evalxfail_key = StoreKey[MarkEvaluator]()
 unexpectedsuccess_key = StoreKey[str]()
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("general")
     group.addoption(
         "--runxfail",
@@ -31,7 +33,7 @@ def pytest_addoption(parser):
     )
 
 
-def pytest_configure(config):
+def pytest_configure(config: Config) -> None:
     if config.option.runxfail:
         # yay a hack
         import pytest
@@ -42,7 +44,7 @@ def pytest_configure(config):
         def nop(*args, **kwargs):
             pass
 
-        nop.Exception = xfail.Exception
+        nop.Exception = xfail.Exception  # type: ignore[attr-defined] # noqa: F821
         setattr(pytest, "xfail", nop)
 
     config.addinivalue_line(

src/_pytest/stepwise.py

@@ -1,7 +1,10 @@
 import pytest
+from _pytest.config import Config
+from _pytest.config.argparsing import Parser
+from _pytest.main import Session
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("general")
     group.addoption(
         "--sw",
@@ -19,7 +22,7 @@ def pytest_addoption(parser):
 
 
 @pytest.hookimpl
-def pytest_configure(config):
+def pytest_configure(config: Config) -> None:
     config.pluginmanager.register(StepwisePlugin(config), "stepwiseplugin")
 
 
@@ -34,7 +37,7 @@ class StepwisePlugin:
             self.lastfailed = config.cache.get("cache/stepwise", None)
             self.skip = config.getvalue("stepwise_skip")
 
-    def pytest_sessionstart(self, session):
+    def pytest_sessionstart(self, session: Session) -> None:
         self.session = session
 
     def pytest_collection_modifyitems(self, session, config, items):
@@ -100,7 +103,7 @@ class StepwisePlugin:
         if self.active and self.config.getoption("verbose") >= 0 and self.report_status:
             return "stepwise: %s" % self.report_status
 
-    def pytest_sessionfinish(self, session):
+    def pytest_sessionfinish(self, session: Session) -> None:
         if self.active:
             self.config.cache.set("cache/stepwise", self.lastfailed)
         else:

src/_pytest/terminal.py

@@ -17,6 +17,7 @@ from typing import Mapping
 from typing import Optional
 from typing import Set
 from typing import Tuple
+from typing import Union
 
 import attr
 import pluggy
@@ -29,8 +30,10 @@ from _pytest import timing
 from _pytest._io import TerminalWriter
 from _pytest._io.wcwidth import wcswidth
 from _pytest.compat import order_preserving_dict
+from _pytest.config import _PluggyPlugin
 from _pytest.config import Config
 from _pytest.config import ExitCode
+from _pytest.config.argparsing import Parser
 from _pytest.deprecated import TERMINALWRITER_WRITER
 from _pytest.main import Session
 from _pytest.reports import CollectReport
@@ -77,7 +80,7 @@ class MoreQuietAction(argparse.Action):
         namespace.quiet = getattr(namespace, "quiet", 0) + 1
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("terminal reporting", "reporting", after="general")
     group._addoption(
         "-v",
@@ -423,7 +426,7 @@ class TerminalReporter:
         )
         self._add_stats("warnings", [warning_report])
 
-    def pytest_plugin_registered(self, plugin):
+    def pytest_plugin_registered(self, plugin: _PluggyPlugin) -> None:
         if self.config.option.traceconfig:
             msg = "PLUGIN registered: {}".format(plugin)
             # XXX this event may happen during setup/teardown time
@@ -717,7 +720,7 @@ class TerminalReporter:
                             self._tw.line("{}{}".format(indent + "  ", line))
 
     @pytest.hookimpl(hookwrapper=True)
-    def pytest_sessionfinish(self, session: Session, exitstatus: ExitCode):
+    def pytest_sessionfinish(self, session: Session, exitstatus: Union[int, ExitCode]):
         outcome = yield
         outcome.get_result()
         self._tw.line("")
@@ -752,10 +755,10 @@ class TerminalReporter:
         # Display any extra warnings from teardown here (if any).
         self.summary_warnings()
 
-    def pytest_keyboard_interrupt(self, excinfo):
+    def pytest_keyboard_interrupt(self, excinfo) -> None:
         self._keyboardinterrupt_memo = excinfo.getrepr(funcargs=True)
 
-    def pytest_unconfigure(self):
+    def pytest_unconfigure(self) -> None:
         if hasattr(self, "_keyboardinterrupt_memo"):
             self._report_keyboardinterrupt()
 

src/_pytest/warnings.py

@@ -8,6 +8,8 @@ from typing import Tuple
 
 import pytest
 from _pytest.compat import TYPE_CHECKING
+from _pytest.config import Config
+from _pytest.config.argparsing import Parser
 from _pytest.main import Session
 
 if TYPE_CHECKING:
@@ -49,7 +51,7 @@ def _parse_filter(
     return (action, message, category, module, lineno)
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("pytest-warnings")
     group.addoption(
         "-W",
@@ -66,7 +68,7 @@ def pytest_addoption(parser):
     )
 
 
-def pytest_configure(config):
+def pytest_configure(config: Config) -> None:
     config.addinivalue_line(
         "markers",
         "filterwarnings(warning): add a warning filter to the given test. "