allow filtering by response

tests/unit/test_vcr.py

@@ -100,6 +100,21 @@ def test_vcr_before_record_response_iterable():
             assert mock_filter.call_count == 1
 
 
+def test_before_record_response_as_filter():
+    request = Request('GET', '/', '', {})
+    response = object()  # just can't be None
+
+    # Prevent actually saving the cassette
+    with mock.patch('vcr.cassette.save_cassette'):
+
+        filter_all = mock.Mock(return_value=None)
+        vcr = VCR(before_record_response=filter_all)
+        with vcr.use_cassette('test') as cassette:
+            cassette.append(request, response)
+            assert cassette.data == []e
+            assert not cassette.dirty
+
+
 def test_vcr_path_transformer():
     # Regression test for #199
 

vcr/cassette.py

@@ -237,6 +237,8 @@ class Cassette(object):
         if not request:
             return
         response = self._before_record_response(response)
+        if response is None:
+            return
         self.data.append((request, response))
         self.dirty = True