move tests into deprecated_test, and test for number of warnings issued

testing/deprecated_test.py

@@ -279,3 +279,35 @@ def test_importing_instance_is_deprecated(pytester: Pytester) -> None:
         match=re.escape("The pytest.Instance collector type is deprecated"),
     ):
         from _pytest.python import Instance  # noqa: F401
+
+
+def test_fixture_disallow_on_marked_functions():
+    """Test that applying @pytest.fixture to a marked function warns (#3364)."""
+    with pytest.warns(
+        pytest.PytestDeprecationWarning,
+        match=r"Marks applied to fixtures have no effect",
+    ) as record:
+
+        @pytest.fixture
+        @pytest.mark.parametrize("example", ["hello"])
+        @pytest.mark.usefixtures("tmp_path")
+        def foo():
+            raise NotImplementedError()
+
+    assert len(record) == 1
+
+
+def test_fixture_disallow_marks_on_fixtures():
+    """Test that applying a mark to a fixture warns (#3364)."""
+    with pytest.warns(
+        pytest.PytestDeprecationWarning,
+        match=r"Marks applied to fixtures have no effect",
+    ) as record:
+
+        @pytest.mark.parametrize("example", ["hello"])
+        @pytest.mark.usefixtures("tmp_path")
+        @pytest.fixture
+        def foo():
+            raise NotImplementedError()
+
+    assert len(record) == 2

testing/python/fixtures.py

@@ -3620,24 +3620,6 @@ class TestShowFixtures:
             def foo():
                 raise NotImplementedError()
 
-    def test_fixture_disallow_on_marked_functions(self):
-        """Test that applying @pytest.fixture to a marked function warns (#3364)."""
-        with pytest.warns(pytest.PytestDeprecationWarning):
-
-            @pytest.fixture
-            @pytest.mark.usefixtures("tmp_path")
-            def foo():
-                raise NotImplementedError()
-
-    def test_fixture_disallow_marks_on_fixtures(self):
-        """Test that applying a mark to a fixture warns (#3364)."""
-        with pytest.warns(pytest.PytestDeprecationWarning):
-
-            @pytest.mark.usefixtures("tmp_path")
-            @pytest.fixture
-            def foo():
-                raise NotImplementedError()
-
 
 class TestContextManagerFixtureFuncs:
     def test_simple(self, pytester: Pytester) -> None: