Add type annotation to visited_chains (#17125)

anoadragon453 · web-flow · commit 646cb6ff2412 · 2024-04-25T12:25:26.000Z
This should fix CI on `develop`. Broke in 0fe9e1f, presumably due to a `mypy` dependency upgrade.
diff --git a/changelog.d/17125.misc b/changelog.d/17125.misc
@@ -0,0 +1 @@
+Fix type annotation for `visited_chains` after `mypy` upgrade.
diff --git a/synapse/storage/databases/main/events.py b/synapse/storage/databases/main/events.py
@@ -2454,7 +2454,7 @@ def exists_path_from(
             return target_seq <= src_seq
 
         # We have to graph traverse the links to check for indirect paths.
-        visited_chains = collections.Counter()
+        visited_chains: Dict[int, int] = collections.Counter()
         search = [(src_chain, src_seq)]
         while search:
             chain, seq = search.pop()

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+Fix type annotation for `visited_chains` after `mypy` upgrade.