Add tests for exception chaining in Python 3.

filmor · filmor · commit 3ba2bf1e8d50 · 2016-11-14T12:08:07.000+01:00
diff --git a/src/testing/exceptiontest.cs b/src/testing/exceptiontest.cs
@@ -1,6 +1,5 @@
 using System;
 
-
 namespace Python.Test
 {
     //========================================================================
@@ -55,6 +54,25 @@ public static bool ThrowException()
         {
             throw new OverflowException("error");
         }
+
+        public static void ThrowChainedExceptions()
+        {
+            try
+            {
+                try
+                {
+                    throw new Exception("Innermost exception");
+                }
+                catch (Exception exc)
+                {
+                    throw new Exception("Inner exception", exc);
+                }
+            }
+            catch (Exception exc2)
+            {
+                throw new Exception("Outer exception", exc2);
+            }
+        }
     }
 
 
diff --git a/src/tests/test_exceptions.py b/src/tests/test_exceptions.py
@@ -345,6 +345,29 @@ def testPicklingExceptions(self):
 
         self.assertEqual(exc.args, loaded.args)
 
+    @unittest.skipIf(six.PY2,
+                     "exception chaining is only supported in Python 3")
+    def testChainedExceptions(self):
+        if six.PY3:
+            from Python.Test import ExceptionTest
+
+            try:
+                ExceptionTest.ThrowChainedExceptions()
+            except Exception as exc:
+                msgs = [
+                    "Outer exception",
+                    "Inner exception",
+                    "Innermost exception"
+                ]
+
+                for msg in msgs:
+                    self.assertEqual(exc.Message, msg)
+                    self.assertEqual(exc.__cause__, exc.InnerException)
+                    exc = exc.__cause__
+
+            else:
+                self.fail("Test should raise an exception")
+
 
 def test_suite():
     return unittest.makeSuite(ExceptionTests)
