Reset client post parameters after each payment_fake test, because the sign…

Reset client post parameters after each payment_fake test, because the sign method modifies the supplied dictionary

lms/djangoapps/shoppingcart/tests/test_payment_fake.py

@@ -15,7 +15,13 @@ class PaymentFakeViewTest(TestCase):
     correctly with the shopping cart.
     """
 
-    CLIENT_POST_PARAMS = OrderedDict([
+    def setUp(self):
+        super(PaymentFakeViewTest, self).setUp()
+
+        # Reset the view state
+        PaymentFakeView.PAYMENT_STATUS_RESPONSE = "success"
+
+        self.client_post_params = OrderedDict([
             ('amount', '25.00'),
             ('currency', 'usd'),
             ('transaction_type', 'sale'),
@@ -31,16 +37,10 @@ class PaymentFakeViewTest(TestCase):
             ('signed_date_time', '2014-08-18T13:59:31Z'),
         ])
 
-    def setUp(self):
-        super(PaymentFakeViewTest, self).setUp()
-
-        # Reset the view state
-        PaymentFakeView.PAYMENT_STATUS_RESPONSE = "success"
-
     def test_accepts_client_signatures(self):
 
         # Generate shoppingcart signatures
-        post_params = sign(self.CLIENT_POST_PARAMS)
+        post_params = sign(self.client_post_params)
 
         # Simulate a POST request from the payment workflow
         # page to the fake payment page.
@@ -58,7 +58,7 @@ class PaymentFakeViewTest(TestCase):
     def test_rejects_invalid_signature(self):
 
         # Generate shoppingcart signatures
-        post_params = sign(self.CLIENT_POST_PARAMS)
+        post_params = sign(self.client_post_params)
 
         # Tamper with the signature
         post_params['signature'] = "invalid"
@@ -75,7 +75,7 @@ class PaymentFakeViewTest(TestCase):
     def test_sends_valid_signature(self):
 
         # Generate shoppingcart signatures
-        post_params = sign(self.CLIENT_POST_PARAMS)
+        post_params = sign(self.client_post_params)
 
         # Get the POST params that the view would send back to us
         resp_params = PaymentFakeView.response_post_params(post_params)
@@ -90,7 +90,7 @@ class PaymentFakeViewTest(TestCase):
     def test_set_payment_status(self):
 
         # Generate shoppingcart signatures
-        post_params = sign(self.CLIENT_POST_PARAMS)
+        post_params = sign(self.client_post_params)
 
         # Configure the view to declined payments
         resp = self.client.put(