Merge pull request #12121 from jakkdl/test_scope_fixture_caching

Add tests to ensure setup&finalization for scoped fixtures only run once.

testing/python/fixtures.py

@@ -4622,3 +4622,77 @@ def test_staticmethod_classmethod_fixture_instance(pytester: Pytester) -> None:
     result = pytester.runpytest()
     assert result.ret == ExitCode.OK
     result.assert_outcomes(passed=3)
+
+
+def test_scoped_fixture_caching(pytester: Pytester) -> None:
+    """Make sure setup and finalization is only run once when using scoped fixture
+    multiple times."""
+    pytester.makepyfile(
+        """
+        from __future__ import annotations
+
+        from typing import Generator
+
+        import pytest
+        executed: list[str] = []
+        @pytest.fixture(scope="class")
+        def fixture_1() -> Generator[None, None, None]:
+            executed.append("fix setup")
+            yield
+            executed.append("fix teardown")
+
+
+        class TestFixtureCaching:
+            def test_1(self, fixture_1: None) -> None:
+                assert executed == ["fix setup"]
+
+            def test_2(self, fixture_1: None) -> None:
+                assert executed == ["fix setup"]
+
+
+        def test_expected_setup_and_teardown() -> None:
+            assert executed == ["fix setup", "fix teardown"]
+        """
+    )
+    result = pytester.runpytest()
+    assert result.ret == 0
+
+
+def test_scoped_fixture_caching_exception(pytester: Pytester) -> None:
+    """Make sure setup & finalization is only run once for scoped fixture, with a cached exception."""
+    pytester.makepyfile(
+        """
+        from __future__ import annotations
+
+        import pytest
+        executed_crash: list[str] = []
+
+
+        @pytest.fixture(scope="class")
+        def fixture_crash(request: pytest.FixtureRequest) -> None:
+            executed_crash.append("fix_crash setup")
+
+            def my_finalizer() -> None:
+                executed_crash.append("fix_crash teardown")
+
+            request.addfinalizer(my_finalizer)
+
+            raise Exception("foo")
+
+
+        class TestFixtureCachingException:
+            @pytest.mark.xfail
+            def test_crash_1(self, fixture_crash: None) -> None:
+                ...
+
+            @pytest.mark.xfail
+            def test_crash_2(self, fixture_crash: None) -> None:
+                ...
+
+
+        def test_crash_expected_setup_and_teardown() -> None:
+            assert executed_crash == ["fix_crash setup", "fix_crash teardown"]
+        """
+    )
+    result = pytester.runpytest()
+    assert result.ret == 0