Fixed a test error that occurred because the problem

was not set to done before resetting it.
To avoid to small chance that we'll get the same seed when
we reset, try to get a new seed multiple times.

common/lib/xmodule/xmodule/tests/test_capa_module.py

@@ -890,31 +890,60 @@ class CapaModuleTest(unittest.TestCase):
             self.assertEqual(seed, module.seed)
 
     def test_random_seed_with_reset(self):
-        rerandomize_options = ['never', 'per_student', 'always', 'onreset']
         
-        for rerandomize in rerandomize_options:
-            module = CapaFactory.create(rerandomize=rerandomize)
+        def _reset_and_get_seed(module):
+            '''
+            Reset the XModule and return the module's seed
+            '''
 
-            # Get the seed
-            seed = module.lcp.seed
+            # Simulate submitting an attempt
+            module.done = True
 
             # Reset the problem
             module.reset_problem({})
 
+            # Get return the seed
+            return module.seed
+
+        def _retry_and_check(num_tries, test_func):
+            '''
+            Returns True if *test_func* was successful
+            (returned True) within *num_tries* attempts
+
+            *test_func* must be a function 
+            of the form test_func() -> bool
+            '''
+            success = False
+            for i in range(num_tries):
+                if test_func() is True:
+                    success = True
+                    break
+            return success
+
+        # Run the test for each possible rerandomize value
+        for rerandomize in ['never', 'per_student', 'always', 'onreset']:
+            module = CapaFactory.create(rerandomize=rerandomize)
+
+            # Get the seed
+            seed = module.lcp.seed
+
             # We do NOT want the seed to reset if rerandomize
             # is set to 'never' -- it should still be 1
             # The seed also stays the same if we're randomizing
             # 'per_student': the same student should see the same problem
             if rerandomize in ['never', 'per_student']:
-                self.assertEqual(seed, module.seed)
+                self.assertEqual(seed, _reset_and_get_seed(module))
 
             # Otherwise, we expect the seed to change
             # to another valid seed
             else:
 
-                # After we save, the seed is stored in the module
-                get_request_dict = { CapaFactory.input_key(): '3.14'}
-                module.save_problem(get_request_dict)
+                # Since there's a small chance we might get the
+                # same seed again, give it 5 chances
+                # to generate a different seed
+                success = _retry_and_check(5, 
+                                lambda: _reset_and_get_seed(module) != seed)
                 
-                self.assertEqual(seed, module.seed)
-                self.assertTrue(module.seed is not None)
+                self.assertTrue(module.seed != None)
+                msg = 'Could not get a new seed from reset after 5 tries'
+                self.assertTrue(success, msg)