Use assertion rather than cast

matrix-org · Oct 3, 2022 · 149fecc · 149fecc
1 parent a37e8e5
commit 149fecc
Showing 1 changed file with 4 additions and 3 deletions.
diff --git a/synapse/handlers/cas.py b/synapse/handlers/cas.py
@@ -130,9 +130,10 @@ async def _validate_ticket(
         except PartialDownloadError as pde:
             # Twisted raises this error if the connection is closed,
             # even if that's being used old-http style to signal end-of-data
-            # Cast safety: Error.response is Optional[bytes]. but a PartialDownloadError
-            # always has a non-None response.
-            body = cast(bytes, pde.response)
+            # Assertion is for mypy's benefit. Error.response is Optional[bytes],
+            # but a PartialDownloadError should always have a non-None response.
+            assert pde.response is not None
+            body = pde.response
         except HttpResponseException as e:
             description = (
                 'Authorization server responded with a "{status}" error '