Change error handling to report back internal errors.

lms/djangoapps/commerce/http.py

 """ HTTP-related entities. """
 
-from rest_framework.status import HTTP_503_SERVICE_UNAVAILABLE, HTTP_200_OK
+from rest_framework.status import HTTP_500_INTERNAL_SERVER_ERROR, HTTP_200_OK
 
 from util.json_request import JsonResponse
 
@@ -13,9 +13,13 @@ class DetailResponse(JsonResponse):
         super(DetailResponse, self).__init__(object=data, status=status)
 
 
-class ApiErrorResponse(DetailResponse):
-    """ Response returned when calls to the E-Commerce API fail or the returned data is invalid. """
+class InternalRequestErrorResponse(DetailResponse):
+    """ Response returned when an internal service request fails. """
 
-    def __init__(self):
-        message = 'Call to E-Commerce API failed. Order creation failed.'
-        super(ApiErrorResponse, self).__init__(message=message, status=HTTP_503_SERVICE_UNAVAILABLE)
+    def __init__(self, internal_message, internal_status):
+        message = (
+            'Call to E-Commerce API failed. Internal Request Status Code: '
+            '[{internal_status}], Internal Service Message: [{internal_message}]'
+            .format(internal_status=internal_status, internal_message=internal_message)
+        )
+        super(InternalRequestErrorResponse, self).__init__(message=message, status=HTTP_500_INTERNAL_SERVER_ERROR)

lms/djangoapps/commerce/tests/test_views.py

@@ -48,10 +48,12 @@ class OrdersViewTests(EnrollmentEventTestMixin, EcommerceApiTestMixin, ModuleSto
         actual = json.loads(response.content)['detail']
         self.assertEqual(actual, expected_msg)
 
-    def assertValidEcommerceApiErrorResponse(self, response):
+    def assertValidEcommerceInternalRequestErrorResponse(self, response, internal_status):
         """ Asserts the response is a valid response sent when the E-Commerce API is unavailable. """
-        self.assertEqual(response.status_code, 503)
-        self.assertResponseMessage(response, 'Call to E-Commerce API failed. Order creation failed.')
+        self.assertEqual(response.status_code, 500)
+        actual = json.loads(response.content)['detail']
+        self.assertIn('Call to E-Commerce API failed', actual)
+        self.assertIn(str(internal_status), actual)
 
     def assertUserNotEnrolled(self):
         """ Asserts that the user is NOT enrolled in the course, and that an enrollment event was NOT fired. """
@@ -112,7 +114,7 @@ class OrdersViewTests(EnrollmentEventTestMixin, EcommerceApiTestMixin, ModuleSto
         with self.mock_create_order(side_effect=TimeoutError):
             response = self._post_to_view()
 
-        self.assertValidEcommerceApiErrorResponse(response)
+        self.assertValidEcommerceInternalRequestErrorResponse(response, 408)
         self.assertUserNotEnrolled()
 
     def test_ecommerce_api_error(self):
@@ -122,7 +124,7 @@ class OrdersViewTests(EnrollmentEventTestMixin, EcommerceApiTestMixin, ModuleSto
         with self.mock_create_order(side_effect=ApiError):
             response = self._post_to_view()
 
-        self.assertValidEcommerceApiErrorResponse(response)
+        self.assertValidEcommerceInternalRequestErrorResponse(response, 500)
         self.assertUserNotEnrolled()
 
     def _test_successful_ecommerce_api_call(self):