ECOM-662 Raise exception in case of DECLINE response.

Adding decline button in fake payment page.
In of case ERROR, CANCEL, and DECLINE removing auth_amount from test cybersource2 and payment fake.

lms/djangoapps/shoppingcart/processors/CyberSource2.py

@@ -142,6 +142,11 @@ def verify_signatures(params):
     if params.get('decision') == u'CANCEL':
         raise CCProcessorUserCancelled()
 
+    #  if the user decline the transaction
+    # if so, then auth_amount will not be passed back so we can't yet verify signatures
+    if params.get('decision') == u'DECLINE':
+        raise CCProcessorUserDeclined()
+
     # Validate the signature to ensure that the message is from CyberSource
     # and has not been tampered with.
     signed_fields = params.get('signed_field_names', '').split(',')
@@ -520,6 +525,15 @@ def _get_processor_exception_html(exception):
                 email=payment_support_email
             )
         )
+    elif isinstance(exception, CCProcessorUserDeclined):
+        return _format_error_html(
+            _(
+                u"We're sorry, but this payment was declined. The items in your shopping cart have been saved. "
+                u"If you have any questions about this transaction, please contact us at {email}."
+            ).format(
+                email=payment_support_email
+            )
+        )
     else:
         return _format_error_html(
             _(

lms/djangoapps/shoppingcart/processors/exceptions.py

@@ -19,3 +19,8 @@ class CCProcessorWrongAmountException(CCProcessorException):
 
 class CCProcessorUserCancelled(CCProcessorException):
     pass
+
+
+class CCProcessorUserDeclined(CCProcessorException):
+    """Transaction declined."""
+    pass

lms/djangoapps/shoppingcart/processors/tests/test_CyberSource2.py

@@ -37,6 +37,7 @@ class CyberSource2Test(TestCase):
 
     COST = "10.00"
     CALLBACK_URL = "/test_callback_url"
+    FAILED_DECISIONS = ["DECLINE", "CANCEL", "ERROR"]
 
     def setUp(self):
         """ Create a user and an order. """
@@ -142,7 +143,7 @@ class CyberSource2Test(TestCase):
 
     def test_process_payment_rejected(self):
         # Simulate a callback from CyberSource indicating that the payment was rejected
-        params = self._signed_callback_params(self.order.id, self.COST, self.COST, accepted=False)
+        params = self._signed_callback_params(self.order.id, self.COST, self.COST, decision='REJECT')
         result = process_postpay_callback(params)
 
         # Expect that we get an error message
@@ -263,7 +264,7 @@ class CyberSource2Test(TestCase):
 
     def _signed_callback_params(
         self, order_id, order_amount, paid_amount,
-        accepted=True, signature=None, card_number='xxxxxxxxxxxx1111',
+        decision='ACCEPT', signature=None, card_number='xxxxxxxxxxxx1111',
         first_name='John'
     ):
         """
@@ -281,7 +282,7 @@ class CyberSource2Test(TestCase):
 
         Keyword Args:
 
-            accepted (bool): Whether the payment was accepted or rejected.
+            decision (string): Whether the payment was accepted or rejected or declined.
             signature (string): If provided, use this value instead of calculating the signature.
             card_numer (string): If provided, use this value instead of the default credit card number.
             first_name (string): If provided, the first name of the user.
@@ -292,9 +293,51 @@ class CyberSource2Test(TestCase):
         """
         # Parameters sent from CyberSource to our callback implementation
         # These were captured from the CC test server.
+
+        signed_field_names = ["transaction_id",
+                              "decision",
+                              "req_access_key",
+                              "req_profile_id",
+                              "req_transaction_uuid",
+                              "req_transaction_type",
+                              "req_reference_number",
+                              "req_amount",
+                              "req_currency",
+                              "req_locale",
+                              "req_payment_method",
+                              "req_override_custom_receipt_page",
+                              "req_bill_to_forename",
+                              "req_bill_to_surname",
+                              "req_bill_to_email",
+                              "req_bill_to_address_line1",
+                              "req_bill_to_address_city",
+                              "req_bill_to_address_state",
+                              "req_bill_to_address_country",
+                              "req_bill_to_address_postal_code",
+                              "req_card_number",
+                              "req_card_type",
+                              "req_card_expiry_date",
+                              "message",
+                              "reason_code",
+                              "auth_avs_code",
+                              "auth_avs_code_raw",
+                              "auth_response",
+                              "auth_amount",
+                              "auth_code",
+                              "auth_trans_ref_no",
+                              "auth_time",
+                              "bill_trans_ref_no",
+                              "signed_field_names",
+                              "signed_date_time"]
+
+        # if decision is in FAILED_DECISIONS list then remove  auth_amount from
+        # signed_field_names list.
+        if decision in self.FAILED_DECISIONS:
+            signed_field_names.remove("auth_amount")
+
         params = {
             # Parameters that change based on the test
-            "decision": "ACCEPT" if accepted else "REJECT",
+            "decision": decision,
             "req_reference_number": str(order_id),
             "req_amount": order_amount,
             "auth_amount": paid_amount,
@@ -307,43 +350,7 @@ class CyberSource2Test(TestCase):
             "req_card_expiry_date": "01-2018",
             "bill_trans_ref_no": "85080648RYI23S6I",
             "req_bill_to_address_state": "MA",
-            "signed_field_names": ",".join([
-                "transaction_id",
-                "decision",
-                "req_access_key",
-                "req_profile_id",
-                "req_transaction_uuid",
-                "req_transaction_type",
-                "req_reference_number",
-                "req_amount",
-                "req_currency",
-                "req_locale",
-                "req_payment_method",
-                "req_override_custom_receipt_page",
-                "req_bill_to_forename",
-                "req_bill_to_surname",
-                "req_bill_to_email",
-                "req_bill_to_address_line1",
-                "req_bill_to_address_city",
-                "req_bill_to_address_state",
-                "req_bill_to_address_country",
-                "req_bill_to_address_postal_code",
-                "req_card_number",
-                "req_card_type",
-                "req_card_expiry_date",
-                "message",
-                "reason_code",
-                "auth_avs_code",
-                "auth_avs_code_raw",
-                "auth_response",
-                "auth_amount",
-                "auth_code",
-                "auth_trans_ref_no",
-                "auth_time",
-                "bill_trans_ref_no",
-                "signed_field_names",
-                "signed_date_time"
-            ]),
+            "signed_field_names": ",".join(signed_field_names),
             "req_payment_method": "card",
             "req_transaction_type": "sale",
             "auth_code": "888888",
@@ -370,6 +377,11 @@ class CyberSource2Test(TestCase):
             "req_access_key": "abcd12345",
         }
 
+        # if decision is in FAILED_DECISIONS list then remove the auth_amount from params dict
+
+        if decision in self.FAILED_DECISIONS:
+            del params["auth_amount"]
+
         # Calculate the signature
         params['signature'] = signature if signature is not None else self._signature(params)
         return params
@@ -398,3 +410,12 @@ class CyberSource2Test(TestCase):
                 in params['signed_field_names'].split(u",")
             ])
         )
+
+    def test_process_payment_declined(self):
+        # Simulate a callback from CyberSource indicating that the payment was declined
+        params = self._signed_callback_params(self.order.id, self.COST, self.COST, decision='DECLINE')
+        result = process_postpay_callback(params)
+
+        # Expect that we get an error message
+        self.assertFalse(result['success'])
+        self.assertIn(u"payment was declined", result['error_html'])

lms/djangoapps/shoppingcart/tests/payment_fake.py

@@ -78,7 +78,7 @@ class PaymentFakeView(View):
         """
         new_status = request.body
 
-        if new_status not in ["success", "failure"]:
+        if new_status not in ["success", "failure", "decline"]:
             return HttpResponseBadRequest()
 
         else:
@@ -109,9 +109,17 @@ class PaymentFakeView(View):
         """
         Calculate the POST params we want to send back to the client.
         """
+
+        if cls.PAYMENT_STATUS_RESPONSE == "success":
+            decision = "ACCEPT"
+        elif cls.PAYMENT_STATUS_RESPONSE == "decline":
+            decision = "DECLINE"
+        else:
+            decision = "REJECT"
+
         resp_params = {
             # Indicate whether the payment was successful
-            "decision": "ACCEPT" if cls.PAYMENT_STATUS_RESPONSE == "success" else "REJECT",
+            "decision": decision,
 
             # Reflect back parameters we were sent by the client
             "req_amount": post_params.get('amount'),
@@ -170,6 +178,13 @@ class PaymentFakeView(View):
             'bill_trans_ref_no', 'signed_field_names', 'signed_date_time'
         ]
 
+        # if decision is decline , cancel or error then remove auth_amount from signed_field.
+        # list and also delete from resp_params dict
+
+        if decision in ["DECLINE", "CANCEL", "ERROR"]:
+            signed_fields.remove('auth_amount')
+            del resp_params["auth_amount"]
+
         # Add the list of signed fields
         resp_params['signed_field_names'] = ",".join(signed_fields)
 
@@ -202,13 +217,27 @@ class PaymentFakeView(View):
         # Build the context dict used to render the HTML form,
         # filling in values for the hidden input fields.
         # These will be sent in the POST request to the callback URL.
+
+        post_params_success = self.response_post_params(post_params)
+
+        # Build the context dict for decline form,
+        # remove the auth_amount value from here to
+        # reproduce exact response coming from actual postback call
+
+        post_params_decline = self.response_post_params(post_params)
+        del post_params_decline["auth_amount"]
+        post_params_decline["decision"] = 'DECLINE'
+
         context_dict = {
 
             # URL to send the POST request to
             "callback_url": callback_url,
 
-            # POST params embedded in the HTML form
-            'post_params': self.response_post_params(post_params)
+            # POST params embedded in the HTML success form
+            'post_params_success': post_params_success,
+
+            # POST params embedded in the HTML decline form
+            'post_params_decline': post_params_decline
         }
 
         return render_to_response('shoppingcart/test/fake_payment_page.html', context_dict)

lms/djangoapps/shoppingcart/tests/test_payment_fake.py

@@ -92,6 +92,17 @@ class PaymentFakeViewTest(TestCase):
         # Generate shoppingcart signatures
         post_params = sign(self.CLIENT_POST_PARAMS)
 
+        # Configure the view to declined payments
+        resp = self.client.put(
+            '/shoppingcart/payment_fake',
+            data="decline", content_type='text/plain'
+        )
+        self.assertEqual(resp.status_code, 200)
+
+        # Check that the decision is "DECLINE"
+        resp_params = PaymentFakeView.response_post_params(post_params)
+        self.assertEqual(resp_params.get('decision'), 'DECLINE')
+
         # Configure the view to fail payments
         resp = self.client.put(
             '/shoppingcart/payment_fake',

lms/templates/shoppingcart/test/fake_payment_page.html

 <html>
-<head><title>Payment Form</title></head>
+<head><title>Payment Form</title>
+</head>
 <body>
-    <p>Payment page</p>
-    <form name="input" action="${callback_url}" method="post">
-        % for name, value in post_params.items():
+<p>Payment page</p>
+
+<form name="input" action="${callback_url}" method="post">
+    % for name, value in post_params_success.items():
         <input type="hidden" name="${name}" value="${value}">
-        % endfor
-        <input type="submit" value="Submit">
-    </form>
+    % endfor
+    <input type="submit" value="Submit">
+</form>
+
+<form name="frm_decline" action="${callback_url}" method="post">
+    % for name, value in post_params_decline.items():
+        <input type="hidden" name="${name}" value="${value}">
+    % endfor
+    <input type="submit" value="Decline" id="decline">
+</form>
+
+
 </body>
 </html>
+
+