test: add delay for flaky focus test (#1762)

Author: huozhi

src/types.ts

@@ -119,7 +119,7 @@ export interface SWRHook {
   ): SWRResponse<Data, Error>
 }
 
-// Middlewares guarantee that a SWRHook receives a key, fetcher, and config as the argument
+// Middleware guarantee that a SWRHook receives a key, fetcher, and config as the argument
 export type Middleware = (
   useSWRNext: SWRHook
 ) => <Data = any, Error = any>(

src/utils/with-middleware.ts

@@ -15,7 +15,7 @@ export const withMiddleware = (
       | [Key, Fetcher<Data> | null, SWRConfiguration | undefined]
   ) => {
     const [key, fn, config] = normalize(args)
-    const middlewares = (config.use || []).concat(middleware)
-    return useSWR<Data, Error>(key, fn, { ...config, use: middlewares })
+    const uses = (config.use || []).concat(middleware)
+    return useSWR<Data, Error>(key, fn, { ...config, use: uses })
   }
 }

test/use-swr-focus.test.tsx

@@ -198,6 +198,7 @@ describe('useSWR - focus', () => {
     // trigger revalidation
     await focusWindow()
     await waitForNextTick()
+    await act(() => sleep(100))
     await screen.findByText('data: 5')
   })