test: add test for _get_wrapped_function

src/_pytest/fixtures.py

@@ -1216,9 +1216,11 @@ class FixtureFunctionDefinition:
         )
         fail(message, pytrace=False)
 
-    def _get_wrapped_function(self):
+    def _get_wrapped_function(self) -> Callable[..., Any]:
         if self._instance is not None:
-            return self._fixture_function.__get__(self._instance)
+            return cast(
+                Callable[..., Any], self._fixture_function.__get__(self._instance)
+            )
         return self._fixture_function
 
 

testing/python/fixtures.py

@@ -1,4 +1,5 @@
 # mypy: allow-untyped-defs
+import inspect
 import os
 from pathlib import Path
 import sys
@@ -3295,6 +3296,33 @@ class TestFixtureMarker:
         assert output1 == output2
 
 
+class FixtureFunctionDefTestClass:
+    def __init__(self) -> None:
+        self.i = 10
+
+    @pytest.fixture
+    def fixture_function_def_test_method(self):
+        return self.i
+
+
+@pytest.fixture
+def fixture_function_def_test_func():
+    return 9
+
+
+def test_get_wrapped_func_returns_method():
+    obj = FixtureFunctionDefTestClass()
+    wrapped_function_result = (
+        obj.fixture_function_def_test_method._get_wrapped_function()
+    )
+    assert inspect.ismethod(wrapped_function_result)
+    assert wrapped_function_result() == 10
+
+
+def test_get_wrapped_func_returns_function():
+    assert fixture_function_def_test_func._get_wrapped_function()() == 9
+
+
 class TestRequestScopeAccess:
     pytestmark = pytest.mark.parametrize(
         ("scope", "ok", "error"),