return when falsy

Co-authored-by: Shu Ding <g@shud.in>
vercel · May 20, 2022 · 20fe03f · 20fe03f
1 parent beaf868
commit 20fe03f
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/subscription/index.ts b/subscription/index.ts
@@ -44,6 +44,7 @@ export const subscription = (<Data, Error>(useSWRNext: SWRHook) =>
     })
 
     useIsomorphicLayoutEffect(() => {
+      if (!key) return
       subscriptions.set(key, (subscriptions.get(key) || 0) + 1)
 
       const onData = (val?: Data) => swr.mutate(val, false)