recwarn: let base exceptions propagate through `pytest.warns` again

Fix #11907.

changelog/11907.bugfix.rst

@@ -0,0 +1 @@
+Fix a regression in pytest 8.0.0 whereby calling :func:`pytest.skip` and similar control-flow exceptions within a :func:`pytest.warns()` block would get suppressed instead of propagating.

src/_pytest/recwarn.py

@@ -20,6 +20,7 @@ import warnings
 
 from _pytest.deprecated import check_ispytest
 from _pytest.fixtures import fixture
+from _pytest.outcomes import Exit
 from _pytest.outcomes import fail
 
 
@@ -302,6 +303,17 @@ class WarningsChecker(WarningsRecorder):
 
         __tracebackhide__ = True
 
+        # BaseExceptions like pytest.{skip,fail,xfail,exit} or Ctrl-C within
+        # pytest.warns should *not* trigger "DID NOT WARN" and get suppressed
+        # when the warning doesn't happen. Control-flow exceptions should always
+        # propagate.
+        if exc_val is not None and (
+            not isinstance(exc_val, Exception)
+            # Exit is an Exception, not a BaseException, for some reason.
+            or isinstance(exc_val, Exit)
+        ):
+            return
+
         def found_str():
             return pformat([record.message for record in self], indent=2)
 

testing/test_recwarn.py

@@ -5,9 +5,10 @@ from typing import Optional
 from typing import Type
 import warnings
 
-from _pytest.pytester import Pytester
-from _pytest.recwarn import WarningsRecorder
 import pytest
+from pytest import ExitCode
+from pytest import Pytester
+from pytest import WarningsRecorder
 
 
 def test_recwarn_stacklevel(recwarn: WarningsRecorder) -> None:
@@ -479,6 +480,71 @@ class TestWarns:
                 warnings.warn("some warning", category=FutureWarning)
                 raise ValueError("some exception")
 
+    def test_skip_within_warns(self, pytester: Pytester) -> None:
+        """Regression test for #11907."""
+        pytester.makepyfile(
+            """
+            import pytest
+
+            def test_it():
+                with pytest.warns(Warning):
+                    pytest.skip("this is OK")
+            """,
+        )
+
+        result = pytester.runpytest()
+        assert result.ret == ExitCode.OK
+        result.assert_outcomes(skipped=1)
+
+    def test_fail_within_warns(self, pytester: Pytester) -> None:
+        """Regression test for #11907."""
+        pytester.makepyfile(
+            """
+            import pytest
+
+            def test_it():
+                with pytest.warns(Warning):
+                    pytest.fail("BOOM")
+            """,
+        )
+
+        result = pytester.runpytest()
+        assert result.ret == ExitCode.TESTS_FAILED
+        result.assert_outcomes(failed=1)
+        assert "DID NOT WARN" not in str(result.stdout)
+
+    def test_exit_within_warns(self, pytester: Pytester) -> None:
+        """Regression test for #11907."""
+        pytester.makepyfile(
+            """
+            import pytest
+
+            def test_it():
+                with pytest.warns(Warning):
+                    pytest.exit()
+            """,
+        )
+
+        result = pytester.runpytest()
+        assert result.ret == ExitCode.INTERRUPTED
+        result.assert_outcomes()
+
+    def test_keyboard_interrupt_within_warns(self, pytester: Pytester) -> None:
+        """Regression test for #11907."""
+        pytester.makepyfile(
+            """
+            import pytest
+
+            def test_it():
+                with pytest.warns(Warning):
+                    raise KeyboardInterrupt()
+            """,
+        )
+
+        result = pytester.runpytest_subprocess()
+        assert result.ret == ExitCode.INTERRUPTED
+        result.assert_outcomes()
+
 
 def test_raise_type_error_on_non_string_warning() -> None:
     """Check pytest.warns validates warning messages are strings (#10865)."""