remove unregisters

src/types.ts

@@ -57,8 +57,8 @@ export interface Configuration<
 }
 
 export type Provider = {
-  setupOnFocus: (cb: () => void) => () => void
-  setupOnReconnect: (cb: () => void) => () => void
+  setupOnFocus: (cb: () => void) => void
+  setupOnReconnect: (cb: () => void) => void
 }
 
 export type SWRHook = <Data = any, Error = any>(

src/utils/web-preset.ts

@@ -1,5 +1,5 @@
 import { Provider } from '../types'
-import { isUndefined } from './helper'
+import { isUndefined, UNDEFINED } from './helper'
 
 /**
  * Due to bug https://bugs.chromium.org/p/chromium/issues/detail?id=678075,
@@ -10,23 +10,11 @@ import { isUndefined } from './helper'
  */
 let online = true
 const isOnline = () => online
-const createNoop = (ret?: any) => () => ret
-const add = 'addEventListener'
-const remove = 'removeEventListener'
 
-type EventAction = 'addEventListener' | 'removeEventListener'
-
-const hasWindow = typeof window !== 'undefined'
+const addWindowEventListener =
+  typeof window !== 'undefined' ? window.addEventListener : UNDEFINED
 const hasDocument = typeof document !== 'undefined'
 
-// For node and React Native, `add/removeEventListener` doesn't exist on window.
-const windowEventListener = (action: EventAction) =>
-  hasWindow && !isUndefined(window[action])
-    ? window[action].bind(window)
-    : createNoop()
-const documentEventListener = (action: EventAction) =>
-  hasDocument ? document[action].bind(document) : createNoop()
-
 const isDocumentVisible = () => {
   const visibilityState = hasDocument && document.visibilityState
   if (!isUndefined(visibilityState)) {
@@ -37,31 +25,22 @@ const isDocumentVisible = () => {
 
 const setupOnFocus = (cb: () => void) => {
   // focus revalidate
-  documentEventListener(add)('visibilitychange', cb)
-  windowEventListener(add)('focus', cb)
-  return () => {
-    documentEventListener(remove)('visibilitychange', cb)
-    windowEventListener(remove)('focus', cb)
-  }
+  if (hasDocument) document.addEventListener('visibilitychange', cb)
+  if (addWindowEventListener) addWindowEventListener('focus', cb)
 }
 
 const setupOnReconnect = (cb: () => void) => {
-  const onOnline = () => {
-    online = true
-    cb()
-  }
-  const onOffline = () => {
-    online = false
-  }
   // reconnect revalidate
-  windowEventListener(add)('online', onOnline)
+  if (addWindowEventListener)
+    addWindowEventListener('online', () => {
+      online = true
+      cb()
+    })
   // nothing to revalidate, just update the status
-  windowEventListener(add)('offline', onOffline)
-
-  return () => {
-    windowEventListener(remove)('online', onOnline)
-    windowEventListener(remove)('offline', onOffline)
-  }
+  if (addWindowEventListener)
+    addWindowEventListener('offline', () => {
+      online = false
+    })
 }
 
 export const preset = {