add test case for asserting missing fixture

src/_pytest/assertion/rewrite.py

@@ -462,7 +462,7 @@ def _format_assertmsg(obj: object) -> str:
 
 def _should_repr_global_name(obj: object) -> bool:
     if callable(obj):
-        return hasattr(obj, "__pytest_wrapped__")
+        return hasattr(obj, "_pytestfixturefunction")
 
     try:
         return not hasattr(obj, "__name__")

src/_pytest/fixtures.py

@@ -1200,6 +1200,9 @@ class FixtureFunctionDefinition:
     ):
         self.name = fixture_function_marker.name or function.__name__
         self.__name__ = self.name
+        # This attribute is only used to check if an arbitrary python object is a fixture.
+        # Using isinstance on every object in code might execute code that is not intended to be executed.
+        # Like lazy loaded classes.
         self._pytestfixturefunction = fixture_function_marker
         self.__pytest_wrapped__ = _PytestWrapper(function)
         self.fixture_function_marker = fixture_function_marker

testing/test_assertrewrite.py

@@ -744,6 +744,23 @@ class TestAssertionRewrite:
         assert "UnicodeDecodeError" not in msg
         assert "UnicodeEncodeError" not in msg
 
+    def test_assert_fixture(self, pytester: Pytester) -> None:
+        pytester.makepyfile(
+            """\
+        import pytest
+        @pytest.fixture
+        def fixt():
+            return 42
+
+        def test_something():  # missing "fixt" argument
+            assert fixt == 42
+            """
+        )
+        result = pytester.runpytest()
+        result.stdout.fnmatch_lines(
+            ["*assert pytest_fixture(<function fixt at *>) == 42*"]
+        )
+
 
 class TestRewriteOnImport:
     def test_pycache_is_a_file(self, pytester: Pytester) -> None: