Merge pull request #126 from edx/jsa/xcom-396

Recover from 400 on enrollment revocation when due to mode mismatch.

ecommerce/extensions/fulfillment/modules.py

@@ -216,9 +216,16 @@ class EnrollmentFulfillmentModule(BaseFulfillmentModule):
                 logger.info('Successfully revoked line [%d].', line.id)
                 return True
             else:
+                # check if the error / message are something we can recover from.
                 data = response.json()
                 detail = data.get('message', '(No details provided.)')
-                logger.error('Failed to revoke fulfillment of Line [%d]: %s', line.id, detail)
+                if response.status_code == 400 and "Enrollment mode mismatch" in detail:
+                    # The user is currently enrolled in different mode than the one
+                    # we are refunding an order for.  Don't revoke that enrollment.
+                    logger.info('Skipping revocation for line [%d]: %s', line.id, detail)
+                    return True
+                else:
+                    logger.error('Failed to revoke fulfillment of Line [%d]: %s', line.id, detail)
         except Exception:  # pylint: disable=broad-except
             logger.exception('Failed to revoke fulfillment of Line [%d].', line.id)
 

ecommerce/extensions/fulfillment/tests/test_modules.py

@@ -111,7 +111,26 @@ class EnrollmentFulfillmentModuleTests(CourseCatalogTestMixin, FulfillmentTestMi
         self.assertEqual(actual, expected)
 
     @httpretty.activate
-    def test_revoke_product_api_error(self):
+    def test_revoke_product_expected_error(self):
+        """
+        If the Enrollment API responds with an expected error, the method should log that revocation was
+        bypassed, and return True.
+        """
+        message = 'Enrollment mode mismatch: active mode=x, requested mode=y. Won\'t deactivate.'
+        body = '{{"message": "{}"}}'.format(message)
+        httpretty.register_uri(httpretty.POST, settings.ENROLLMENT_API_URL, status=400, body=body, content_type=JSON)
+
+        line = self.order.lines.first()
+        logger_name = 'ecommerce.extensions.fulfillment.modules'
+        with LogCapture(logger_name) as l:
+            self.assertTrue(EnrollmentFulfillmentModule().revoke_line(line))
+            l.check(
+                (logger_name, 'INFO', 'Attempting to revoke fulfillment of Line [{}]...'.format(line.id)),
+                (logger_name, 'INFO', 'Skipping revocation for line [%d]: %s' % (line.id, message))
+            )
+
+    @httpretty.activate
+    def test_revoke_product_unexpected_error(self):
         """ If the Enrollment API responds with a non-200 status, the method should log an error and return False. """
         message = 'Meh.'
         body = '{{"message": "{}"}}'.format(message)