Fix stale fixture finalizers after setup errors

AUTHORS

@@ -311,6 +311,7 @@ Mark Dickinson
 Mark Vong
 Marko Pacak
 Markus Unterwaditzer
+Marthala Jagruthi Reddy
 Martijn Faassen
 Martin Altmayer
 Martin K. Scherer

changelog/14800.bugfix.rst

@@ -0,0 +1,2 @@
+Fixes an internal assertion when a parametrized fixture setup fails in a
+``pytest_fixture_setup`` hook, allowing subsequent parameters to run normally.

src/_pytest/fixtures.py

@@ -1205,9 +1205,9 @@ def addfinalizer(self, finalizer: Callable[[], object]) -> None:
         self._finalizers.append(finalizer)
 
     def finish(self, request: SubRequest) -> None:
-        if self.cached_result is None:
-            # Already finished. It is assumed that finalizers cannot be added in
-            # this state.
+        if self.cached_result is None and not self._finalizers:
+            # Already finished. If finalizers are present, fixture setup failed
+            # before the result could be cached, so they still need to run.
             return
 
         exceptions: list[BaseException] = []

testing/acceptance_test.py

@@ -1521,6 +1521,38 @@ def test_foo(async_fixture):
     )
 
 
+def test_sync_tests_with_async_autouse_fixture_do_not_poison_later_tests(
+    pytester: Pytester,
+) -> None:
+    pytester.makepyfile(
+        test_sync="""
+            import pytest
+
+            @pytest.fixture(autouse=True)
+            async def async_fixture():
+                yield
+
+            def test_first():
+                pass
+
+            def test_second():
+                pass
+
+            def test_third():
+                pass
+        """
+    )
+    result = pytester.runpytest()
+    result.assert_outcomes(errors=3)
+    result.stdout.fnmatch_lines(
+        [
+            "*'test_first' requested an async fixture 'async_fixture' with autouse=True, *",
+            "*'test_second' requested an async fixture 'async_fixture' with autouse=True, *",
+            "*'test_third' requested an async fixture 'async_fixture' with autouse=True, *",
+        ]
+    )
+
+
 def test_pdb_can_be_rewritten(pytester: Pytester) -> None:
     pytester.makepyfile(
         **{

testing/python/fixtures.py

@@ -4536,6 +4536,42 @@ def test_second(my_fixture):
     )
 
 
+def test_fixture_setup_hook_exception_does_not_leave_stale_finalizers(
+    pytester: Pytester,
+) -> None:
+    """A fixture setup hook failure must not poison later parametrized cases (#14800)."""
+    pytester.makeconftest(
+        """
+        import pytest
+
+        @pytest.hookimpl(tryfirst=True)
+        def pytest_fixture_setup(fixturedef, request):
+            param = getattr(request, "param", None)
+            if isinstance(param, str) and param.startswith("fixture:"):
+                request.param = request.getfixturevalue(param[len("fixture:"):])
+        """
+    )
+    pytester.makepyfile(
+        test_fixtures="""
+        import pytest
+
+        @pytest.fixture
+        def skipping_base():
+            pytest.skip("backend unavailable")
+
+        @pytest.fixture
+        def derived(skipping_base):
+            return "derived"
+
+        @pytest.mark.parametrize("value", ["fixture:derived", "plain-1", "plain-2"])
+        def test_value(value):
+            assert isinstance(value, str)
+        """
+    )
+    result = pytester.runpytest("-v")
+    result.assert_outcomes(passed=2, skipped=1)
+
+
 class TestParamValueKey:
     """Unit tests for the equivalence key used by `reorder_items` (#8914)."""