1 files changed, 35 insertions, 0 deletions
diff --git a/oslo_utils/tests/test_excutils.py b/oslo_utils/tests/test_excutils.py
index c2626a4..60f752d 100644
--- a/oslo_utils/tests/test_excutils.py
+++ b/oslo_utils/tests/test_excutils.py
@@ -25,6 +25,41 @@ from oslo_utils import excutils
 mox = moxstubout.mox
 
 
+class Fail1(excutils.CausedByException):
+    pass
+
+
+class Fail2(excutils.CausedByException):
+    pass
+
+
+class CausedByTest(test_base.BaseTestCase):
+
+    def test_caused_by_explicit(self):
+        e = self.assertRaises(Fail1,
+                              excutils.raise_with_cause,
+                              Fail1, "I was broken",
+                              cause=Fail2("I have been broken"))
+        self.assertIsInstance(e.cause, Fail2)
+        e_p = e.pformat()
+        self.assertIn("I have been broken", e_p)
+        self.assertIn("Fail2", e_p)
+
+    def test_caused_by_implicit(self):
+
+        def raises_chained():
+            try:
+                raise Fail2("I have been broken")
+            except Fail2:
+                excutils.raise_with_cause(Fail1, "I was broken")
+
+        e = self.assertRaises(Fail1, raises_chained)
+        self.assertIsInstance(e.cause, Fail2)
+        e_p = e.pformat()
+        self.assertIn("I have been broken", e_p)
+        self.assertIn("Fail2", e_p)
+
+
 class SaveAndReraiseTest(test_base.BaseTestCase):
 
     def test_save_and_reraise_exception(self):