Merge pull request #7418 from bluetech/typing-3

More typing work

changelog/7418.breaking.rst

@@ -0,0 +1,2 @@
+Remove the `pytest_doctest_prepare_content` hook specification. This hook
+hasn't been triggered by pytest for at least 10 years.

src/_pytest/fixtures.py

@@ -924,9 +924,7 @@ def _teardown_yield_fixture(fixturefunc, it) -> None:
     except StopIteration:
         pass
     else:
-        fail_fixturefunc(
+        fail_fixturefunc(fixturefunc, "fixture function has more than one 'yield'")
-            fixturefunc, "yield_fixture function has more than one 'yield'"
-        )
 
 
 def _eval_scope_callable(

src/_pytest/freeze_support.py

@@ -2,9 +2,13 @@
 Provides a function to report all internal modules for using freezing tools
 pytest
 """
+import types
+from typing import Iterator
+from typing import List
+from typing import Union
 
 
-def freeze_includes():
+def freeze_includes() -> List[str]:
     """
     Returns a list of module names used by pytest that should be
     included by cx_freeze.
@@ -17,7 +21,9 @@ def freeze_includes():
     return result
 
 
-def _iter_all_modules(package, prefix=""):
+def _iter_all_modules(
+    package: Union[str, types.ModuleType], prefix: str = "",
+) -> Iterator[str]:
     """
     Iterates over the names of all modules that can be found in the given
     package, recursively.
@@ -29,10 +35,13 @@ def _iter_all_modules(package, prefix=""):
     import os
     import pkgutil
 
-    if type(package) is not str:
+    if isinstance(package, str):
-        path, prefix = package.__path__[0], package.__name__ + "."
-    else:
         path = package
+    else:
+        # Type ignored because typeshed doesn't define ModuleType.__path__
+        # (only defined on packages).
+        package_path = package.__path__  # type: ignore[attr-defined]
+        path, prefix = package_path[0], package.__name__ + "."
     for _, name, is_package in pkgutil.iter_modules([path]):
         if is_package:
             for m in _iter_all_modules(os.path.join(path, name), prefix=name + "."):

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 Dict
 from typing import List
 from typing import Mapping
 from typing import Optional
@@ -37,7 +38,6 @@ if TYPE_CHECKING:
     from _pytest.python import Metafunc
     from _pytest.python import Module
     from _pytest.python import PyCollector
-    from _pytest.reports import BaseReport
     from _pytest.reports import CollectReport
     from _pytest.reports import TestReport
     from _pytest.runner import CallInfo
@@ -172,7 +172,7 @@ def pytest_cmdline_preparse(config: "Config", args: List[str]) -> None:
 
 
 @hookspec(firstresult=True)
-def pytest_cmdline_main(config: "Config") -> "Optional[Union[ExitCode, int]]":
+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.
 
@@ -206,7 +206,7 @@ def pytest_load_initial_conftests(
 
 
 @hookspec(firstresult=True)
-def pytest_collection(session: "Session") -> Optional[Any]:
+def pytest_collection(session: "Session") -> Optional[object]:
     """Perform the collection protocol for the given session.
 
     Stops at first non-None result, see :ref:`firstresult`.
@@ -242,20 +242,21 @@ def pytest_collection_modifyitems(
     """
 
 
-def pytest_collection_finish(session: "Session"):
+def pytest_collection_finish(session: "Session") -> None:
-    """ called after collection has been performed and modified.
+    """Called after collection has been performed and modified.
 
     :param _pytest.main.Session session: the pytest session object
     """
 
 
 @hookspec(firstresult=True)
-def pytest_ignore_collect(path, config: "Config"):
+def pytest_ignore_collect(path: py.path.local, config: "Config") -> Optional[bool]:
-    """ return True to prevent considering this path for collection.
+    """Return True to prevent considering this path for collection.
+
     This hook is consulted for all files and directories prior to calling
     more specific hooks.
 
-    Stops at first non-None result, see :ref:`firstresult`
+    Stops at first non-None result, see :ref:`firstresult`.
 
     :param path: a :py:class:`py.path.local` - the path to analyze
     :param _pytest.config.Config config: pytest config object
@@ -263,18 +264,19 @@ def pytest_ignore_collect(path, config: "Config"):
 
 
 @hookspec(firstresult=True, warn_on_impl=COLLECT_DIRECTORY_HOOK)
-def pytest_collect_directory(path, parent):
+def pytest_collect_directory(path: py.path.local, parent) -> Optional[object]:
-    """ called before traversing a directory for collection files.
+    """Called before traversing a directory for collection files.
 
-    Stops at first non-None result, see :ref:`firstresult`
+    Stops at first non-None result, see :ref:`firstresult`.
 
     :param path: a :py:class:`py.path.local` - the path to analyze
     """
 
 
 def pytest_collect_file(path: py.path.local, parent) -> "Optional[Collector]":
-    """ return collection Node or None for the given path. Any new node
+    """Return collection Node or None for the given path.
-    needs to have the specified ``parent`` as a parent.
+
+    Any new node needs to have the specified ``parent`` as a parent.
 
     :param path: a :py:class:`py.path.local` - the path to collect
     """
@@ -287,16 +289,16 @@ def pytest_collectstart(collector: "Collector") -> None:
     """ collector starts collecting. """
 
 
-def pytest_itemcollected(item):
+def pytest_itemcollected(item: "Item") -> None:
-    """ we just collected a test item. """
+    """We just collected a test item."""
 
 
 def pytest_collectreport(report: "CollectReport") -> None:
     """ collector finished collecting. """
 
 
-def pytest_deselected(items):
+def pytest_deselected(items: Sequence["Item"]) -> None:
-    """ called for test items deselected, e.g. by keyword. """
+    """Called for deselected test items, e.g. by keyword."""
 
 
 @hookspec(firstresult=True)
@@ -312,13 +314,14 @@ def pytest_make_collect_report(collector: "Collector") -> "Optional[CollectRepor
 
 
 @hookspec(firstresult=True)
-def pytest_pycollect_makemodule(path: py.path.local, parent) -> "Optional[Module]":
+def pytest_pycollect_makemodule(path: py.path.local, parent) -> Optional["Module"]:
-    """ return a Module collector or None for the given path.
+    """Return a Module collector or None for the given path.
+
     This hook will be called for each matching test module path.
     The pytest_collect_file hook needs to be used if you want to
     create test modules for files that do not match as a test module.
 
-    Stops at first non-None result, see :ref:`firstresult`
+    Stops at first non-None result, see :ref:`firstresult`.
 
     :param path: a :py:class:`py.path.local` - the path of module to collect
     """
@@ -326,11 +329,12 @@ def pytest_pycollect_makemodule(path: py.path.local, parent) -> "Optional[Module
 
 @hookspec(firstresult=True)
 def pytest_pycollect_makeitem(
-    collector: "PyCollector", name: str, obj
+    collector: "PyCollector", name: str, obj: object
-) -> "Union[None, Item, Collector, List[Union[Item, Collector]]]":
+) -> Union[None, "Item", "Collector", List[Union["Item", "Collector"]]]:
-    """ return custom item/collector for a python object in a module, or None.
+    """Return a custom item/collector for a Python object in a module, or None.
 
-    Stops at first non-None result, see :ref:`firstresult` """
+    Stops at first non-None result, see :ref:`firstresult`.
+    """
 
 
 @hookspec(firstresult=True)
@@ -466,7 +470,7 @@ def pytest_runtest_call(item: "Item") -> None:
     """
 
 
-def pytest_runtest_teardown(item: "Item", nextitem: "Optional[Item]") -> None:
+def pytest_runtest_teardown(item: "Item", nextitem: Optional["Item"]) -> None:
     """Called to perform the teardown phase for a test item.
 
     The default implementation runs the finalizers and calls ``teardown()``
@@ -505,7 +509,9 @@ def pytest_runtest_logreport(report: "TestReport") -> None:
 
 
 @hookspec(firstresult=True)
-def pytest_report_to_serializable(config: "Config", report: "BaseReport"):
+def pytest_report_to_serializable(
+    config: "Config", report: Union["CollectReport", "TestReport"],
+) -> Optional[Dict[str, Any]]:
     """
     Serializes the given report object into a data structure suitable for sending
     over the wire, e.g. converted to JSON.
@@ -513,7 +519,9 @@ def pytest_report_to_serializable(config: "Config", report: "BaseReport"):
 
 
 @hookspec(firstresult=True)
-def pytest_report_from_serializable(config: "Config", data):
+def pytest_report_from_serializable(
+    config: "Config", data: Dict[str, Any],
+) -> Optional[Union["CollectReport", "TestReport"]]:
     """
     Restores a report object previously serialized with pytest_report_to_serializable().
     """
@@ -528,11 +536,11 @@ def pytest_report_from_serializable(config: "Config", data):
 def pytest_fixture_setup(
     fixturedef: "FixtureDef", request: "SubRequest"
 ) -> Optional[object]:
-    """ performs fixture setup execution.
+    """Performs fixture setup execution.
 
-    :return: The return value of the call to the fixture function
+    :return: The return value of the call to the fixture function.
 
-    Stops at first non-None result, see :ref:`firstresult`
+    Stops at first non-None result, see :ref:`firstresult`.
 
     .. note::
         If the fixture function returns None, other implementations of
@@ -555,7 +563,7 @@ def pytest_fixture_post_finalizer(
 
 
 def pytest_sessionstart(session: "Session") -> None:
-    """ called after the ``Session`` object has been created and before performing collection
+    """Called after the ``Session`` object has been created and before performing collection
     and entering the run test loop.
 
     :param _pytest.main.Session session: the pytest session object
@@ -563,9 +571,9 @@ def pytest_sessionstart(session: "Session") -> None:
 
 
 def pytest_sessionfinish(
-    session: "Session", exitstatus: "Union[int, ExitCode]"
+    session: "Session", exitstatus: Union[int, "ExitCode"],
 ) -> None:
-    """ called after whole test run finished, right before returning the exit status to the system.
+    """Called after whole test run finished, right before returning the exit status to the system.
 
     :param _pytest.main.Session session: the pytest session object
     :param int exitstatus: the status which pytest will return to the system
@@ -573,7 +581,7 @@ def pytest_sessionfinish(
 
 
 def pytest_unconfigure(config: "Config") -> None:
-    """ called before test process is exited.
+    """Called before test process is exited.
 
     :param _pytest.config.Config config: pytest config object
     """
@@ -587,7 +595,7 @@ def pytest_unconfigure(config: "Config") -> None:
 def pytest_assertrepr_compare(
     config: "Config", op: str, left: object, right: object
 ) -> Optional[List[str]]:
-    """return explanation for comparisons in failing assert expressions.
+    """Return explanation for comparisons in failing assert expressions.
 
     Return None for no custom explanation, otherwise return a list
     of strings.  The strings will be joined by newlines but any newlines
@@ -598,7 +606,7 @@ def pytest_assertrepr_compare(
     """
 
 
-def pytest_assertion_pass(item, lineno: int, orig: str, expl: str) -> None:
+def pytest_assertion_pass(item: "Item", lineno: int, orig: str, expl: str) -> None:
     """
     **(Experimental)**
 
@@ -665,12 +673,12 @@ def pytest_report_header(
 
 
 def pytest_report_collectionfinish(
-    config: "Config", startdir: py.path.local, items: "Sequence[Item]"
+    config: "Config", startdir: py.path.local, items: Sequence["Item"],
 ) -> Union[str, List[str]]:
     """
     .. versionadded:: 3.2
 
-    return a string or list of strings to be displayed after collection has finished successfully.
+    Return a string or list of strings to be displayed after collection has finished successfully.
 
     These strings will be displayed after the standard "collected X items" message.
 
@@ -689,7 +697,7 @@ def pytest_report_collectionfinish(
 
 @hookspec(firstresult=True)
 def pytest_report_teststatus(
-    report: "BaseReport", config: "Config"
+    report: Union["CollectReport", "TestReport"], config: "Config"
 ) -> Tuple[
     str, str, Union[str, Mapping[str, bool]],
 ]:
@@ -734,7 +742,7 @@ def pytest_terminal_summary(
 def pytest_warning_captured(
     warning_message: "warnings.WarningMessage",
     when: "Literal['config', 'collect', 'runtest']",
-    item: "Optional[Item]",
+    item: Optional["Item"],
     location: Optional[Tuple[str, int, str]],
 ) -> None:
     """(**Deprecated**) Process a warning captured by the internal pytest warnings plugin.
@@ -797,18 +805,6 @@ def pytest_warning_recorded(
     """
 
 
-# -------------------------------------------------------------------------
-# doctest hooks
-# -------------------------------------------------------------------------
-
-
-@hookspec(firstresult=True)
-def pytest_doctest_prepare_content(content):
-    """ return processed content for a given doctest
-
-    Stops at first non-None result, see :ref:`firstresult` """
-
-
 # -------------------------------------------------------------------------
 # error handling and internal debugging hooks
 # -------------------------------------------------------------------------
@@ -831,7 +827,9 @@ def pytest_keyboard_interrupt(
 
 
 def pytest_exception_interact(
-    node: "Node", call: "CallInfo[object]", report: "Union[CollectReport, TestReport]"
+    node: "Node",
+    call: "CallInfo[object]",
+    report: Union["CollectReport", "TestReport"],
 ) -> None:
     """Called when an exception was raised which can potentially be
     interactively handled.

src/_pytest/main.py

@@ -302,8 +302,8 @@ def _main(config: Config, session: "Session") -> Optional[Union[int, ExitCode]]:
     return None
 
 
-def pytest_collection(session: "Session") -> Sequence[nodes.Item]:
+def pytest_collection(session: "Session") -> None:
-    return session.perform_collect()
+    session.perform_collect()
 
 
 def pytest_runtestloop(session: "Session") -> bool:
@@ -343,9 +343,7 @@ def _in_venv(path: py.path.local) -> bool:
     return any([fname.basename in activates for fname in bindir.listdir()])
 
 
-def pytest_ignore_collect(
+def pytest_ignore_collect(path: py.path.local, config: Config) -> Optional[bool]:
-    path: py.path.local, config: Config
-) -> "Optional[Literal[True]]":
     ignore_paths = config._getconftest_pathlist("collect_ignore", path=path.dirpath())
     ignore_paths = ignore_paths or []
     excludeopt = config.getoption("ignore")

src/_pytest/python.py

@@ -422,7 +422,7 @@ class PyCollector(PyobjMixin, nodes.Collector):
         return values
 
     def _makeitem(
-        self, name: str, obj
+        self, name: str, obj: object
     ) -> Union[
         None, nodes.Item, nodes.Collector, List[Union[nodes.Item, nodes.Collector]]
     ]:

src/_pytest/python_api.py

@@ -33,7 +33,7 @@ if TYPE_CHECKING:
 BASE_TYPE = (type, STRING_TYPES)
 
 
-def _non_numeric_type_error(value, at):
+def _non_numeric_type_error(value, at: Optional[str]) -> TypeError:
     at_str = " at {}".format(at) if at else ""
     return TypeError(
         "cannot make approximate comparisons to non-numeric values: {!r} {}".format(
@@ -55,7 +55,7 @@ class ApproxBase:
     __array_ufunc__ = None
     __array_priority__ = 100
 
-    def __init__(self, expected, rel=None, abs=None, nan_ok=False):
+    def __init__(self, expected, rel=None, abs=None, nan_ok: bool = False) -> None:
         __tracebackhide__ = True
         self.expected = expected
         self.abs = abs
@@ -63,10 +63,10 @@ class ApproxBase:
         self.nan_ok = nan_ok
         self._check_type()
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         raise NotImplementedError
 
-    def __eq__(self, actual):
+    def __eq__(self, actual) -> bool:
         return all(
             a == self._approx_scalar(x) for a, x in self._yield_comparisons(actual)
         )
@@ -74,10 +74,10 @@ class ApproxBase:
     # Ignore type because of https://github.com/python/mypy/issues/4266.
     __hash__ = None  # type: ignore
 
-    def __ne__(self, actual):
+    def __ne__(self, actual) -> bool:
         return not (actual == self)
 
-    def _approx_scalar(self, x):
+    def _approx_scalar(self, x) -> "ApproxScalar":
         return ApproxScalar(x, rel=self.rel, abs=self.abs, nan_ok=self.nan_ok)
 
     def _yield_comparisons(self, actual):
@@ -87,7 +87,7 @@ class ApproxBase:
         """
         raise NotImplementedError
 
-    def _check_type(self):
+    def _check_type(self) -> None:
         """
         Raise a TypeError if the expected value is not a valid type.
         """
@@ -111,11 +111,11 @@ class ApproxNumpy(ApproxBase):
     Perform approximate comparisons where the expected value is numpy array.
     """
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         list_scalars = _recursive_list_map(self._approx_scalar, self.expected.tolist())
         return "approx({!r})".format(list_scalars)
 
-    def __eq__(self, actual):
+    def __eq__(self, actual) -> bool:
         import numpy as np
 
         # self.expected is supposed to always be an array here
@@ -154,12 +154,12 @@ class ApproxMapping(ApproxBase):
     numeric values (the keys can be anything).
     """
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return "approx({!r})".format(
             {k: self._approx_scalar(v) for k, v in self.expected.items()}
         )
 
-    def __eq__(self, actual):
+    def __eq__(self, actual) -> bool:
         if set(actual.keys()) != set(self.expected.keys()):
             return False
 
@@ -169,7 +169,7 @@ class ApproxMapping(ApproxBase):
         for k in self.expected.keys():
             yield actual[k], self.expected[k]
 
-    def _check_type(self):
+    def _check_type(self) -> None:
         __tracebackhide__ = True
         for key, value in self.expected.items():
             if isinstance(value, type(self.expected)):
@@ -185,7 +185,7 @@ class ApproxSequencelike(ApproxBase):
     numbers.
     """
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         seq_type = type(self.expected)
         if seq_type not in (tuple, list, set):
             seq_type = list
@@ -193,7 +193,7 @@ class ApproxSequencelike(ApproxBase):
             seq_type(self._approx_scalar(x) for x in self.expected)
         )
 
-    def __eq__(self, actual):
+    def __eq__(self, actual) -> bool:
         if len(actual) != len(self.expected):
             return False
         return ApproxBase.__eq__(self, actual)
@@ -201,7 +201,7 @@ class ApproxSequencelike(ApproxBase):
     def _yield_comparisons(self, actual):
         return zip(actual, self.expected)
 
-    def _check_type(self):
+    def _check_type(self) -> None:
         __tracebackhide__ = True
         for index, x in enumerate(self.expected):
             if isinstance(x, type(self.expected)):
@@ -223,7 +223,7 @@ class ApproxScalar(ApproxBase):
     DEFAULT_ABSOLUTE_TOLERANCE = 1e-12  # type: Union[float, Decimal]
     DEFAULT_RELATIVE_TOLERANCE = 1e-6  # type: Union[float, Decimal]
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         """
         Return a string communicating both the expected value and the tolerance
         for the comparison being made, e.g. '1.0 ± 1e-6', '(3+4j) ± 5e-6 ∠ ±180°'.
@@ -245,7 +245,7 @@ class ApproxScalar(ApproxBase):
 
         return "{} ± {}".format(self.expected, vetted_tolerance)
 
-    def __eq__(self, actual):
+    def __eq__(self, actual) -> bool:
         """
         Return true if the given value is equal to the expected value within
         the pre-specified tolerance.
@@ -275,7 +275,8 @@ class ApproxScalar(ApproxBase):
             return False
 
         # Return true if the two numbers are within the tolerance.
-        return abs(self.expected - actual) <= self.tolerance
+        result = abs(self.expected - actual) <= self.tolerance  # type: bool
+        return result
 
     # Ignore type because of https://github.com/python/mypy/issues/4266.
     __hash__ = None  # type: ignore
@@ -337,7 +338,7 @@ class ApproxDecimal(ApproxScalar):
     DEFAULT_RELATIVE_TOLERANCE = Decimal("1e-6")
 
 
-def approx(expected, rel=None, abs=None, nan_ok=False):
+def approx(expected, rel=None, abs=None, nan_ok: bool = False) -> ApproxBase:
     """
     Assert that two numbers (or two sets of numbers) are equal to each other
     within some tolerance.
@@ -527,7 +528,7 @@ def approx(expected, rel=None, abs=None, nan_ok=False):
     return cls(expected, rel, abs, nan_ok)
 
 
-def _is_numpy_array(obj):
+def _is_numpy_array(obj: object) -> bool:
     """
     Return true if the given object is a numpy array.  Make a special effort to
     avoid importing numpy unless it's really necessary.

src/_pytest/recwarn.py

@@ -4,24 +4,29 @@ import warnings
 from types import TracebackType
 from typing import Any
 from typing import Callable
+from typing import Generator
 from typing import Iterator
 from typing import List
 from typing import Optional
 from typing import Pattern
 from typing import Tuple
+from typing import TypeVar
 from typing import Union
 
 from _pytest.compat import overload
 from _pytest.compat import TYPE_CHECKING
-from _pytest.fixtures import yield_fixture
+from _pytest.fixtures import fixture
 from _pytest.outcomes import fail
 
 if TYPE_CHECKING:
     from typing import Type
 
 
-@yield_fixture
+T = TypeVar("T")
-def recwarn():
+
+
+@fixture
+def recwarn() -> Generator["WarningsRecorder", None, None]:
     """Return a :class:`WarningsRecorder` instance that records all warnings emitted by test functions.
 
     See http://docs.python.org/library/warnings.html for information
@@ -33,9 +38,26 @@ def recwarn():
         yield wrec
 
 
-def deprecated_call(func=None, *args, **kwargs):
+@overload
-    """context manager that can be used to ensure a block of code triggers a
+def deprecated_call(
-    ``DeprecationWarning`` or ``PendingDeprecationWarning``::
+    *, match: Optional[Union[str, "Pattern"]] = ...
+) -> "WarningsRecorder":
+    raise NotImplementedError()
+
+
+@overload  # noqa: F811
+def deprecated_call(  # noqa: F811
+    func: Callable[..., T], *args: Any, **kwargs: Any
+) -> T:
+    raise NotImplementedError()
+
+
+def deprecated_call(  # noqa: F811
+    func: Optional[Callable] = None, *args: Any, **kwargs: Any
+) -> Union["WarningsRecorder", Any]:
+    """Assert that code produces a ``DeprecationWarning`` or ``PendingDeprecationWarning``.
+
+    This function can be used as a context manager::
 
         >>> import warnings
         >>> def api_call_v2():
@@ -45,9 +67,15 @@ def deprecated_call(func=None, *args, **kwargs):
         >>> with deprecated_call():
         ...    assert api_call_v2() == 200
 
-    ``deprecated_call`` can also be used by passing a function and ``*args`` and ``*kwargs``,
+    It can also be used by passing a function and ``*args`` and ``**kwargs``,
-    in which case it will ensure calling ``func(*args, **kwargs)`` produces one of the warnings
+    in which case it will ensure calling ``func(*args, **kwargs)`` produces one of
-    types above.
+    the warnings types above. The return value is the return value of the function.
+
+    In the context manager form you may use the keyword argument ``match`` to assert
+    that the warning matches a text or regex.
+
+    The context manager produces a list of :class:`warnings.WarningMessage` objects,
+    one for each warning raised.
     """
     __tracebackhide__ = True
     if func is not None:
@@ -67,11 +95,10 @@ def warns(
 @overload  # noqa: F811
 def warns(  # noqa: F811
     expected_warning: Optional[Union["Type[Warning]", Tuple["Type[Warning]", ...]]],
-    func: Callable,
+    func: Callable[..., T],
     *args: Any,
-    match: Optional[Union[str, "Pattern"]] = ...,
     **kwargs: Any
-) -> Union[Any]:
+) -> T:
     raise NotImplementedError()
 
 
@@ -97,7 +124,7 @@ def warns(  # noqa: F811
         ...    warnings.warn("my warning", RuntimeWarning)
 
     In the context manager form you may use the keyword argument ``match`` to assert
-    that the exception matches a text or regex::
+    that the warning matches a text or regex::
 
         >>> with warns(UserWarning, match='must be 0 or None'):
         ...     warnings.warn("value must be 0 or None", UserWarning)

src/_pytest/reports.py

@@ -1,6 +1,7 @@
 from io import StringIO
 from pprint import pprint
 from typing import Any
+from typing import Dict
 from typing import Iterable
 from typing import Iterator
 from typing import List
@@ -69,7 +70,7 @@ class BaseReport:
         def __getattr__(self, key: str) -> Any:
             raise NotImplementedError()
 
-    def toterminal(self, out) -> None:
+    def toterminal(self, out: TerminalWriter) -> None:
         if hasattr(self, "node"):
             out.line(getworkerinfoline(self.node))
 
@@ -187,7 +188,7 @@ class BaseReport:
         )
         return verbose
 
-    def _to_json(self):
+    def _to_json(self) -> Dict[str, Any]:
         """
         This was originally the serialize_report() function from xdist (ca03269).
 
@@ -199,7 +200,7 @@ class BaseReport:
         return _report_to_json(self)
 
     @classmethod
-    def _from_json(cls: "Type[_R]", reportdict) -> _R:
+    def _from_json(cls: "Type[_R]", reportdict: Dict[str, object]) -> _R:
         """
         This was originally the serialize_report() function from xdist (ca03269).
 
@@ -382,11 +383,13 @@ class CollectErrorRepr(TerminalRepr):
     def __init__(self, msg) -> None:
         self.longrepr = msg
 
-    def toterminal(self, out) -> None:
+    def toterminal(self, out: TerminalWriter) -> None:
         out.line(self.longrepr, red=True)
 
 
-def pytest_report_to_serializable(report: BaseReport):
+def pytest_report_to_serializable(
+    report: Union[CollectReport, TestReport]
+) -> Optional[Dict[str, Any]]:
     if isinstance(report, (TestReport, CollectReport)):
         data = report._to_json()
         data["$report_type"] = report.__class__.__name__
@@ -394,7 +397,9 @@ def pytest_report_to_serializable(report: BaseReport):
     return None
 
 
-def pytest_report_from_serializable(data) -> Optional[BaseReport]:
+def pytest_report_from_serializable(
+    data: Dict[str, Any],
+) -> Optional[Union[CollectReport, TestReport]]:
     if "$report_type" in data:
         if data["$report_type"] == "TestReport":
             return TestReport._from_json(data)
@@ -406,7 +411,7 @@ def pytest_report_from_serializable(data) -> Optional[BaseReport]:
     return None
 
 
-def _report_to_json(report: BaseReport):
+def _report_to_json(report: BaseReport) -> Dict[str, Any]:
     """
     This was originally the serialize_report() function from xdist (ca03269).
 
@@ -414,7 +419,9 @@ def _report_to_json(report: BaseReport):
     serialization.
     """
 
-    def serialize_repr_entry(entry: Union[ReprEntry, ReprEntryNative]):
+    def serialize_repr_entry(
+        entry: Union[ReprEntry, ReprEntryNative]
+    ) -> Dict[str, Any]:
         data = attr.asdict(entry)
         for key, value in data.items():
             if hasattr(value, "__dict__"):
@@ -422,25 +429,28 @@ def _report_to_json(report: BaseReport):
         entry_data = {"type": type(entry).__name__, "data": data}
         return entry_data
 
-    def serialize_repr_traceback(reprtraceback: ReprTraceback):
+    def serialize_repr_traceback(reprtraceback: ReprTraceback) -> Dict[str, Any]:
         result = attr.asdict(reprtraceback)
         result["reprentries"] = [
             serialize_repr_entry(x) for x in reprtraceback.reprentries
         ]
         return result
 
-    def serialize_repr_crash(reprcrash: Optional[ReprFileLocation]):
+    def serialize_repr_crash(
+        reprcrash: Optional[ReprFileLocation],
+    ) -> Optional[Dict[str, Any]]:
         if reprcrash is not None:
             return attr.asdict(reprcrash)
         else:
             return None
 
-    def serialize_longrepr(rep):
+    def serialize_longrepr(rep: BaseReport) -> Dict[str, Any]:
+        assert rep.longrepr is not None
         result = {
             "reprcrash": serialize_repr_crash(rep.longrepr.reprcrash),
             "reprtraceback": serialize_repr_traceback(rep.longrepr.reprtraceback),
             "sections": rep.longrepr.sections,
-        }
+        }  # type: Dict[str, Any]
         if isinstance(rep.longrepr, ExceptionChainRepr):
             result["chain"] = []
             for repr_traceback, repr_crash, description in rep.longrepr.chain:
@@ -473,7 +483,7 @@ def _report_to_json(report: BaseReport):
     return d
 
 
-def _report_kwargs_from_json(reportdict):
+def _report_kwargs_from_json(reportdict: Dict[str, Any]) -> Dict[str, Any]:
     """
     This was originally the serialize_report() function from xdist (ca03269).
 

src/_pytest/terminal.py

@@ -473,9 +473,9 @@ class TerminalReporter:
     def line(self, msg: str, **kw: bool) -> None:
         self._tw.line(msg, **kw)
 
-    def _add_stats(self, category: str, items: List) -> None:
+    def _add_stats(self, category: str, items: Sequence) -> None:
         set_main_color = category not in self.stats
-        self.stats.setdefault(category, []).extend(items[:])
+        self.stats.setdefault(category, []).extend(items)
         if set_main_color:
             self._set_main_color()
 
@@ -505,7 +505,7 @@ class TerminalReporter:
             #     which garbles our output if we use self.write_line
             self.write_line(msg)
 
-    def pytest_deselected(self, items) -> None:
+    def pytest_deselected(self, items: Sequence[Item]) -> None:
         self._add_stats("deselected", items)
 
     def pytest_runtest_logstart(

src/_pytest/unittest.py

@@ -44,7 +44,7 @@ if TYPE_CHECKING:
 
 
 def pytest_pycollect_makeitem(
-    collector: PyCollector, name: str, obj
+    collector: PyCollector, name: str, obj: object
 ) -> Optional["UnitTestCase"]:
     # has unittest been imported and is obj a subclass of its TestCase?
     try:

testing/example_scripts/issue_519.py

@@ -33,13 +33,13 @@ def checked_order():
     ]
 
 
-@pytest.yield_fixture(scope="module")
+@pytest.fixture(scope="module")
 def fix1(request, arg1, checked_order):
     checked_order.append((request.node.name, "fix1", arg1))
     yield "fix1-" + arg1
 
 
-@pytest.yield_fixture(scope="function")
+@pytest.fixture(scope="function")
 def fix2(request, fix1, arg2, checked_order):
     checked_order.append((request.node.name, "fix2", arg2))
     yield "fix2-" + arg2 + fix1

testing/python/approx.py

@@ -3,6 +3,7 @@ from decimal import Decimal
 from fractions import Fraction
 from operator import eq
 from operator import ne
+from typing import Optional
 
 import pytest
 from pytest import approx
@@ -121,18 +122,22 @@ class TestApprox:
             assert a == approx(x, rel=5e-1, abs=0.0)
             assert a != approx(x, rel=5e-2, abs=0.0)
 
-    def test_negative_tolerance(self):
+    @pytest.mark.parametrize(
+        ("rel", "abs"),
+        [
+            (-1e100, None),
+            (None, -1e100),
+            (1e100, -1e100),
+            (-1e100, 1e100),
+            (-1e100, -1e100),
+        ],
+    )
+    def test_negative_tolerance(
+        self, rel: Optional[float], abs: Optional[float]
+    ) -> None:
         # Negative tolerances are not allowed.
-        illegal_kwargs = [
-            dict(rel=-1e100),
-            dict(abs=-1e100),
-            dict(rel=1e100, abs=-1e100),
-            dict(rel=-1e100, abs=1e100),
-            dict(rel=-1e100, abs=-1e100),
-        ]
-        for kwargs in illegal_kwargs:
         with pytest.raises(ValueError):
-                1.1 == approx(1, **kwargs)
+            1.1 == approx(1, rel, abs)
 
     def test_inf_tolerance(self):
         # Everything should be equal if the tolerance is infinite.
@@ -143,19 +148,21 @@ class TestApprox:
             assert a == approx(x, rel=0.0, abs=inf)
             assert a == approx(x, rel=inf, abs=inf)
 
-    def test_inf_tolerance_expecting_zero(self):
+    def test_inf_tolerance_expecting_zero(self) -> None:
         # If the relative tolerance is zero but the expected value is infinite,
         # the actual tolerance is a NaN, which should be an error.
-        illegal_kwargs = [dict(rel=inf, abs=0.0), dict(rel=inf, abs=inf)]
-        for kwargs in illegal_kwargs:
         with pytest.raises(ValueError):
-                1 == approx(0, **kwargs)
+            1 == approx(0, rel=inf, abs=0.0)
+        with pytest.raises(ValueError):
+            1 == approx(0, rel=inf, abs=inf)
 
-    def test_nan_tolerance(self):
+    def test_nan_tolerance(self) -> None:
-        illegal_kwargs = [dict(rel=nan), dict(abs=nan), dict(rel=nan, abs=nan)]
-        for kwargs in illegal_kwargs:
         with pytest.raises(ValueError):
-                1.1 == approx(1, **kwargs)
+            1.1 == approx(1, rel=nan)
+        with pytest.raises(ValueError):
+            1.1 == approx(1, abs=nan)
+        with pytest.raises(ValueError):
+            1.1 == approx(1, rel=nan, abs=nan)
 
     def test_reasonable_defaults(self):
         # Whatever the defaults are, they should work for numbers close to 1

testing/python/fixtures.py

@@ -1315,7 +1315,7 @@ class TestFixtureUsages:
 
             DB_INITIALIZED = None
 
-            @pytest.yield_fixture(scope="session", autouse=True)
+            @pytest.fixture(scope="session", autouse=True)
             def db():
                 global DB_INITIALIZED
                 DB_INITIALIZED = True
@@ -2960,8 +2960,7 @@ class TestFixtureMarker:
             """
             import pytest
 
-            @pytest.yield_fixture(params=[object(), object()],
+            @pytest.fixture(params=[object(), object()], ids=['alpha', 'beta'])
-                                  ids=['alpha', 'beta'])
             def fix(request):
                  yield request.param
 

testing/test_doctest.py

@@ -1176,7 +1176,7 @@ class TestDoctestAutoUseFixtures:
             import pytest
             import sys
 
-            @pytest.yield_fixture(autouse=True, scope='session')
+            @pytest.fixture(autouse=True, scope='session')
             def myfixture():
                 assert not hasattr(sys, 'pytest_session_data')
                 sys.pytest_session_data = 1

testing/test_pathlib.py

@@ -91,7 +91,7 @@ class TestImportPath:
     Having our own pyimport-like function is inline with removing py.path dependency in the future.
     """
 
-    @pytest.yield_fixture(scope="session")
+    @pytest.fixture(scope="session")
     def path1(self, tmpdir_factory):
         path = tmpdir_factory.mktemp("path")
         self.setuptestfs(path)

testing/test_recwarn.py

@@ -370,13 +370,14 @@ class TestWarns:
 
     @pytest.mark.filterwarnings("ignore")
     def test_can_capture_previously_warned(self) -> None:
-        def f():
+        def f() -> int:
             warnings.warn(UserWarning("ohai"))
             return 10
 
         assert f() == 10
         assert pytest.warns(UserWarning, f) == 10
         assert pytest.warns(UserWarning, f) == 10
+        assert pytest.warns(UserWarning, f) != "10"  # type: ignore[comparison-overlap]
 
     def test_warns_context_manager_with_kwargs(self) -> None:
         with pytest.raises(TypeError) as excinfo: