Add helper to check HttpResponse containing csv

shared/tests/testcases.py

@@ -1,3 +1,4 @@
+import csv
 from unittest import mock
 from urllib.parse import parse_qs, urlparse
 
@@ -92,6 +93,10 @@ class TestCaseMixin:
         else:
             self.assertEqual(actual, expected)
 
+    def load_from_csv_response(self, r):
+        decoded = r.content.decode('utf-8')
+        return list(csv.reader(decoded.split('\n')[:-1]))
+
 
 class ViewTestCaseMixin(TestCaseMixin):
     """