From 7e7503c0b015f61d9d21d3b5f55990b7fcd683f7 Mon Sep 17 00:00:00 2001
From: Daniel Miller <millerdev@gmail.com>
Date: Sat, 27 Apr 2024 08:49:05 -0400
Subject: [PATCH] unittest: report class cleanup exceptions (#12250)

Fixes #11728

---------

Co-authored-by: Bruno Oliveira <bruno@soliv.dev>
---
 AUTHORS                         |  1 +
 changelog/11728.improvement.rst |  1 +
 src/_pytest/unittest.py         | 19 +++++++
 testing/test_unittest.py        | 89 +++++++++++++++++++++++++++++++++
 4 files changed, 110 insertions(+)
 create mode 100644 changelog/11728.improvement.rst

diff --git a/AUTHORS b/AUTHORS
index d7148acfc51..4f61c05914b 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -101,6 +101,7 @@ Cyrus Maden
 Damian Skrzypczak
 Daniel Grana
 Daniel Hahler
+Daniel Miller
 Daniel Nuri
 Daniel Sánchez Castelló
 Daniel Valenzuela Zenteno
diff --git a/changelog/11728.improvement.rst b/changelog/11728.improvement.rst
new file mode 100644
index 00000000000..1e87fc5ed88
--- /dev/null
+++ b/changelog/11728.improvement.rst
@@ -0,0 +1 @@
+For ``unittest``-based tests, exceptions during class cleanup (as raised by functions registered with :meth:`TestCase.addClassCleanup <unittest.TestCase.addClassCleanup>`) are now reported instead of silently failing.
diff --git a/src/_pytest/unittest.py b/src/_pytest/unittest.py
index 5099904fd41..8f1791bf744 100644
--- a/src/_pytest/unittest.py
+++ b/src/_pytest/unittest.py
@@ -32,6 +32,9 @@
 import pytest
 
 
+if sys.version_info[:2] < (3, 11):
+    from exceptiongroup import ExceptionGroup
+
 if TYPE_CHECKING:
     import unittest
 
@@ -111,6 +114,20 @@ def _register_unittest_setup_class_fixture(self, cls: type) -> None:
             return None
         cleanup = getattr(cls, "doClassCleanups", lambda: None)
 
+        def process_teardown_exceptions() -> None:
+            # tearDown_exceptions is a list set in the class containing exc_infos for errors during
+            # teardown for the class.
+            exc_infos = getattr(cls, "tearDown_exceptions", None)
+            if not exc_infos:
+                return
+            exceptions = [exc for (_, exc, _) in exc_infos]
+            # If a single exception, raise it directly as this provides a more readable
+            # error (hopefully this will improve in #12255).
+            if len(exceptions) == 1:
+                raise exceptions[0]
+            else:
+                raise ExceptionGroup("Unittest class cleanup errors", exceptions)
+
         def unittest_setup_class_fixture(
             request: FixtureRequest,
         ) -> Generator[None, None, None]:
@@ -125,6 +142,7 @@ def unittest_setup_class_fixture(
                 # follow this here.
                 except Exception:
                     cleanup()
+                    process_teardown_exceptions()
                     raise
             yield
             try:
@@ -132,6 +150,7 @@ def unittest_setup_class_fixture(
                     teardown()
             finally:
                 cleanup()
+                process_teardown_exceptions()
 
         self.session._fixturemanager._register_fixture(
             # Use a unique name to speed up lookup.
diff --git a/testing/test_unittest.py b/testing/test_unittest.py
index 9ecb548eeec..d726e74d603 100644
--- a/testing/test_unittest.py
+++ b/testing/test_unittest.py
@@ -1500,6 +1500,95 @@ def test_cleanup_called_the_right_number_of_times():
     assert passed == 1
 
 
+class TestClassCleanupErrors:
+    """
+    Make sure to show exceptions raised during class cleanup function (those registered
+    via addClassCleanup()).
+
+    See #11728.
+    """
+
+    def test_class_cleanups_failure_in_setup(self, pytester: Pytester) -> None:
+        testpath = pytester.makepyfile(
+            """
+            import unittest
+            class MyTestCase(unittest.TestCase):
+                @classmethod
+                def setUpClass(cls):
+                    def cleanup(n):
+                        raise Exception(f"fail {n}")
+                    cls.addClassCleanup(cleanup, 2)
+                    cls.addClassCleanup(cleanup, 1)
+                    raise Exception("fail 0")
+                def test(self):
+                    pass
+        """
+        )
+        result = pytester.runpytest("-s", testpath)
+        result.assert_outcomes(passed=0, errors=1)
+        result.stdout.fnmatch_lines(
+            [
+                "*Unittest class cleanup errors *2 sub-exceptions*",
+                "*Exception: fail 1",
+                "*Exception: fail 2",
+            ]
+        )
+        result.stdout.fnmatch_lines(
+            [
+                "* ERROR at setup of MyTestCase.test *",
+                "E * Exception: fail 0",
+            ]
+        )
+
+    def test_class_cleanups_failure_in_teardown(self, pytester: Pytester) -> None:
+        testpath = pytester.makepyfile(
+            """
+            import unittest
+            class MyTestCase(unittest.TestCase):
+                @classmethod
+                def setUpClass(cls):
+                    def cleanup(n):
+                        raise Exception(f"fail {n}")
+                    cls.addClassCleanup(cleanup, 2)
+                    cls.addClassCleanup(cleanup, 1)
+                def test(self):
+                    pass
+        """
+        )
+        result = pytester.runpytest("-s", testpath)
+        result.assert_outcomes(passed=1, errors=1)
+        result.stdout.fnmatch_lines(
+            [
+                "*Unittest class cleanup errors *2 sub-exceptions*",
+                "*Exception: fail 1",
+                "*Exception: fail 2",
+            ]
+        )
+
+    def test_class_cleanup_1_failure_in_teardown(self, pytester: Pytester) -> None:
+        testpath = pytester.makepyfile(
+            """
+            import unittest
+            class MyTestCase(unittest.TestCase):
+                @classmethod
+                def setUpClass(cls):
+                    def cleanup(n):
+                        raise Exception(f"fail {n}")
+                    cls.addClassCleanup(cleanup, 1)
+                def test(self):
+                    pass
+        """
+        )
+        result = pytester.runpytest("-s", testpath)
+        result.assert_outcomes(passed=1, errors=1)
+        result.stdout.fnmatch_lines(
+            [
+                "*ERROR at teardown of MyTestCase.test*",
+                "*Exception: fail 1",
+            ]
+        )
+
+
 def test_traceback_pruning(pytester: Pytester) -> None:
     """Regression test for #9610 - doesn't crash during traceback pruning."""
     pytester.makepyfile(