Mark yield_fixture as deprecated (#14342)

Co-authored-by: Marco Gorelli
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: The-Compiler

changelog/14342.improvement.rst

@@ -0,0 +1,2 @@
+Marked ``yield_fixture`` as deprecated to type checkers using the ``deprecated`` decorator. Note it
+:ref:`has originally been deprecated <yield-fixture-deprecated>` in pytest 6.2 already.

doc/en/deprecations.rst

@@ -287,6 +287,8 @@ conflicts (such as :class:`pytest.File` now taking ``path`` instead of
 deprecation warning is now raised.
 
 
+.. _yield-fixture-deprecated:
+
 The ``yield_fixture`` function/decorator
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

src/_pytest/fixtures.py

@@ -32,6 +32,7 @@
 from typing import TypeVar
 import warnings
 
+from .compat import deprecated
 import _pytest
 from _pytest import nodes
 from _pytest._code import getfslineno
@@ -1416,6 +1417,10 @@ def fixture(
     return fixture_marker
 
 
+@deprecated(
+    "@pytest.yield_fixture is deprecated. Use @pytest.fixture instead; they are the same.",
+    category=None,  # We have our own runtime warning logic
+)
 def yield_fixture(
     fixture_function=None,
     *args,

src/pytest/__init__.py

@@ -26,7 +26,7 @@
 from _pytest.fixtures import FixtureDef
 from _pytest.fixtures import FixtureLookupError
 from _pytest.fixtures import FixtureRequest
-from _pytest.fixtures import yield_fixture
+from _pytest.fixtures import yield_fixture  # type: ignore[deprecated]
 from _pytest.freeze_support import freeze_includes
 from _pytest.legacypath import TempdirFactory
 from _pytest.legacypath import Testdir

testing/deprecated_test.py

@@ -68,7 +68,7 @@ def pytest_runtest_call(self):
 def test_yield_fixture_is_deprecated() -> None:
     with pytest.warns(DeprecationWarning, match=r"yield_fixture is deprecated"):
 
-        @pytest.yield_fixture
+        @pytest.yield_fixture  # type: ignore[deprecated]
         def fix():
             assert False