Lint that comments are text_type

Author: gsnedders

html5lib/filters/lint.py

@@ -49,7 +49,8 @@ def __iter__(self):
                     assert start == (namespace, name)
 
             elif type == "Comment":
-                pass
+                data = token["data"]
+                assert isinstance(data, text_type)
 
             elif type in ("Characters", "SpaceCharacters"):
                 data = token["data"]