fix: handled exception gracefully and returned proper response (#300)

* fix: handled exception gracefully and returned proper response

* fix: liniting issues

* refactor: logged error and returned appropriate message

* refactor: updated log message

* test: added unit tests for graceful exception handling

commerce_coordinator/apps/frontend_app_ecommerce/tests/test_views.py

@@ -44,6 +44,7 @@ class OrdersViewTests(TestCase):
     test_user_username = 'test'  # Different from ORDER_HISTORY_GET_PARAMETERS username.
     test_user_email = '[email protected]'
     test_user_password = 'secret'
+    url = reverse('frontend_app_ecommerce:order_history')
 
     def setUp(self):
         """Create test user before test starts."""
@@ -69,7 +70,7 @@ def test_view_rejects_post(self, _mock_ctorders, _mock_ecommerce_client):
         self.client.login(username=self.test_user_username, password=self.test_user_password)
 
         # Perform POST
-        response = self.client.post(reverse('frontend_app_ecommerce:order_history'), ORDER_HISTORY_GET_PARAMETERS)
+        response = self.client.post(self.url, ORDER_HISTORY_GET_PARAMETERS)
 
         # Check 405 Method Not Allowed
         self.assertEqual(response.status_code, 405)
@@ -78,7 +79,7 @@ def test_view_rejects_unauthorized(self, _mock_ctorders, _mock_ecommerce_client)
         """Check unauthorized users querying orders are redirected to login page."""
 
         # Perform GET without logging in.
-        response = self.client.get(reverse('frontend_app_ecommerce:order_history'), ORDER_HISTORY_GET_PARAMETERS)
+        response = self.client.get(self.url, ORDER_HISTORY_GET_PARAMETERS)
 
         # Check 302 Found with redirect to login page.
         self.assertEqual(response.status_code, 302)
@@ -91,7 +92,7 @@ def test_view_returns_ok(self, _mock_ctorders, _mock_ecommerce_client):
         self.client.login(username=self.test_user_username, password=self.test_user_password)
 
         # Perform GET
-        response = self.client.get(reverse('frontend_app_ecommerce:order_history'), ORDER_HISTORY_GET_PARAMETERS)
+        response = self.client.get(self.url, ORDER_HISTORY_GET_PARAMETERS)
         # Check 200 OK
         self.assertEqual(response.status_code, 200)
 
@@ -104,7 +105,7 @@ def test_view_returns_expected_ecommerce_response(self, is_redirect_mock, _mock_
         self.client.login(username=self.test_user_username, password=self.test_user_password)
 
         # Perform GET
-        response = self.client.get(reverse('frontend_app_ecommerce:order_history'), ORDER_HISTORY_GET_PARAMETERS)
+        response = self.client.get(self.url, ORDER_HISTORY_GET_PARAMETERS)
 
         # Check expected response
         self.assertEqual(response.json()['results'][1], ECOMMERCE_REQUEST_EXPECTED_RESPONSE['results'][0])
@@ -116,14 +117,33 @@ def test_view_passes_username(self, _mock_ctorders, mock_ecommerce_client):
         self.client.login(username=self.test_user_username, password=self.test_user_password)
 
         # Perform GET
-        self.client.get(reverse('frontend_app_ecommerce:order_history'), ORDER_HISTORY_GET_PARAMETERS)
+        self.client.get(self.url, ORDER_HISTORY_GET_PARAMETERS)
 
         # Get username sent to ecommerce client
         request_username = mock_ecommerce_client.call_args.args[0]['username']
 
         # Check username is passed to ecommerce client
         self.assertEqual(request_username, self.test_user_username)
 
+    @patch(
+        'commerce_coordinator.apps.commercetools.pipeline.GetCommercetoolsOrders.run_filter',
+        side_effect=Exception('Something went wrong')
+    )
+    def test_view_crashes_with_some_error(self, _mock_pipeline, _mock_ctorders, _mock_ecommerce_client):
+        """Check exception is handled gracefully if pipeline crashes."""
+
+        # Login
+        self.client.login(username=self.test_user_username, password=self.test_user_password)
+
+        # Perform GET request
+        response = self.client.get(self.url, ORDER_HISTORY_GET_PARAMETERS)
+
+        # Assert the response status is 400
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+
+        # Assert the response content matches the error message
+        self.assertEqual(response.data, 'Something went wrong!')
+
 
 @ddt.ddt
 class ReceiptRedirectViewTests(APITestCase):

commerce_coordinator/apps/frontend_app_ecommerce/views.py

@@ -10,7 +10,7 @@
 from edx_rest_framework_extensions.permissions import LoginRedirectIfUnauthenticated
 from rest_framework.exceptions import PermissionDenied
 from rest_framework.response import Response
-from rest_framework.status import HTTP_303_SEE_OTHER
+from rest_framework.status import HTTP_303_SEE_OTHER, HTTP_400_BAD_REQUEST
 from rest_framework.throttling import UserRateThrottle
 from rest_framework.views import APIView
 
@@ -94,18 +94,23 @@ def get(self, request):
         if not request.user.lms_user_id:  # pragma: no cover
             raise PermissionDenied(detail="Could not detect LMS user id.")
 
-        order_data = OrderHistoryRequested.run_filter(request, params)
+        try:
+            order_data = OrderHistoryRequested.run_filter(request, params)
 
-        output_orders = []
+            output_orders = []
 
-        for order_set in order_data:
-            output_orders.extend(order_set['results'])
+            for order_set in order_data:
+                output_orders.extend(order_set['results'])
 
-        output = {
-            "count": request.query_params['page_size'],  # This suppresses the ecomm mfe Order History Pagination ctrl
-            "next": None,
-            "previous": None,
-            "results": sorted(output_orders, key=lambda item: date_conv(item["date_placed"]), reverse=True)
-        }
+            output = {
+                # This suppresses the ecomm mfe Order History Pagination control
+                "count": request.query_params['page_size'],
+                "next": None,
+                "previous": None,
+                "results": sorted(output_orders, key=lambda item: date_conv(item["date_placed"]), reverse=True)
+            }
 
-        return Response(output)
+            return Response(output)
+        except Exception as exc:  # pylint: disable=broad-except
+            logger.error(f'[UserOrdersView] An error occured while fetching Order History.\n Data: [{exc}]')
+            return Response(status=HTTP_400_BAD_REQUEST, data='Something went wrong!')