Handle Python 3.12 behaviour.

canonical · Nov 23, 2023 · 43d0a91 · 43d0a91
1 parent 26c6e95
commit 43d0a91
Showing 1 changed file with 12 additions and 2 deletions.
diff --git a/test/test_framework.py b/test/test_framework.py
@@ -537,16 +537,26 @@ class MyEvents(ops.ObjectEvents):
         with self.assertRaises(RuntimeError) as cm:
             class OtherEvents(ops.ObjectEvents):  # type: ignore
                 foo = event
+        # Python 3.12+ raises the original exception with a note, but earlier
+        # Python chains the exceptions.
+        if hasattr(cm.exception, "__notes__"):
+            cause = str(cm.exception)
+        else:
+            cause = str(cm.exception.__cause__)
         self.assertEqual(
-            str(cm.exception.__cause__),
+            cause,
             "EventSource(MyEvent) reused as MyEvents.foo and OtherEvents.foo")
 
         with self.assertRaises(RuntimeError) as cm:
             class MyNotifier(ops.Object):  # type: ignore
                 on = MyEvents()  # type: ignore
                 bar = event
+        if hasattr(cm.exception, "__notes__"):
+            cause = str(cm.exception)
+        else:
+            cause = str(cm.exception.__cause__)
         self.assertEqual(
-            str(cm.exception.__cause__),
+            cause,
             "EventSource(MyEvent) reused as MyEvents.foo and MyNotifier.bar")
 
     def test_reemit_ignores_unknown_event_type(self):