From 7afa2e66439725d1c9b5b81d7bac552bd70b58ce Mon Sep 17 00:00:00 2001
From: Nemanja Tosic <nemanja@livingspec.com>
Date: Sun, 30 May 2021 13:42:01 +0200
Subject: [PATCH] Fix beforeunload memory leak

---
 src/y-websocket.js | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/y-websocket.js b/src/y-websocket.js
index 09234493..b92b5bd5 100644
--- a/src/y-websocket.js
+++ b/src/y-websocket.js
@@ -277,9 +277,10 @@ export class WebsocketProvider extends Observable {
       broadcastMessage(this, encoding.toUint8Array(encoder))
     }
     if (typeof window !== 'undefined') {
-      window.addEventListener('beforeunload', () => {
+      this._beforeUnloadHandler = () => {
         awarenessProtocol.removeAwarenessStates(this.awareness, [doc.clientID], 'window unload')
-      })
+      };
+      window.addEventListener('beforeunload', this._beforeUnloadHandler)
     }
     awareness.on('update', this._awarenessUpdateHandler)
     this._checkInterval = /** @type {any} */ (setInterval(() => {
@@ -315,6 +316,9 @@ export class WebsocketProvider extends Observable {
     }
     clearInterval(this._checkInterval)
     this.disconnect()
+    if (this._beforeUnloadHandler) {
+      window.removeEventListener('beforeunload', this._beforeUnloadHandler)
+    }
     this.awareness.off('update', this._awarenessUpdateHandler)
     this.doc.off('update', this._updateHandler)
     super.destroy()