fix: emit resume event, silent disconnects, error event param (#3192)

* src: Fix shardResumed event not being emitted

* docs: Document Client#error again

* src: Fix onError due to incorrect typings

* src: handle onError properly for both uws and ws

* src: Try to fix silent disconnects when using uWs

* fix(WebSocketShard): uws emits plain objects, not errors

Emitting line of code: 39aa429f94/src/uws.js (L80-L83)
Listener attaching is here: https://github.com/discordjs/uws/blob/master/src/uws.js#L128
For reference, found a clue here: https://github.com/discordjs/discord.js/issues/1528

src/client/websocket/WebSocketManager.js

@@ -194,15 +194,6 @@ class WebSocketManager {
         if (!this.shardQueue.size) this.reconnecting = false;
       });
 
-      shard.on(ShardEvents.RESUMED, () => {
-        /**
-         * Emitted when a shard resumes successfully.
-         * @event Client#shardResumed
-         * @param {number} id The shard ID that resumed
-         */
-        this.client.emit(Events.SHARD_RESUMED, shard.id);
-      });
-
       shard.on(ShardEvents.CLOSE, event => {
         if (event.code === 1000 ? this.destroyed : UNRECOVERABLE_CLOSE_CODES.includes(event.code)) {
           /**

src/client/websocket/WebSocketShard.js

@@ -239,7 +239,7 @@ class WebSocketShard extends EventEmitter {
 
   /**
    * Called whenever a message is received.
-   * @param {Event} event Event received
+   * @param {MessageEvent} event Event received
    * @private
    */
   onMessage({ data }) {
@@ -266,11 +266,14 @@ class WebSocketShard extends EventEmitter {
 
   /**
    * Called whenever an error occurs with the WebSocket.
-   * @param {ErrorEvent} error The error that occurred
+   * @param {ErrorEvent|Object} event The error that occurred
    * @private
    */
-  onError({ error }) {
-    if (error && error.message === 'uWs client connection error') {
+  onError(event) {
+    const error = event && event.error ? event.error : error;
+    if (!error) return;
+
+    if (error.message === 'uWs client connection error') {
       this.debug('Received a uWs error. Closing the connection and reconnecting...');
       this.connection.close(4000);
       return;
@@ -295,6 +298,11 @@ class WebSocketShard extends EventEmitter {
    * @see {@link https://developer.mozilla.org/en-US/docs/Web/API/ErrorEvent}
    */
 
+  /**
+   * @external MessageEvent
+   * @see {@link https://developer.mozilla.org/en-US/docs/Web/API/MessageEvent}
+   */
+
   /**
    * Called whenever a connection to the gateway is closed.
    * @param {CloseEvent} event Close event that was received
@@ -581,7 +589,7 @@ class WebSocketShard extends EventEmitter {
     this.setHeartbeatTimer(-1);
     this.setHelloTimeout(-1);
     // Close the WebSocket connection, if any
-    if (this.connection) {
+    if (this.connection && this.connection.readyState !== WebSocket.CLOSED) {
       this.connection.close(closeCode);
     } else {
       /**

src/client/websocket/handlers/RESUMED.js

@@ -5,10 +5,10 @@ const { Events } = require('../../../util/Constants');
 module.exports = (client, packet, shard) => {
   const replayed = shard.sequence - shard.closeSequence;
   /**
-   * Emitted when the client gateway resumes.
-   * @event Client#resume
-   * @param {number} replayed The number of events that were replayed
-   * @param {number} shardID The ID of the shard that resumed
+   * Emitted when a shard resumes successfully.
+   * @event Client#shardResumed
+   * @param {number} id The shard ID that resumed
+   * @param {number} replayedEvents The amount of replayed events
    */
-  client.emit(Events.RESUMED, replayed, shard.id);
+  client.emit(Events.SHARD_RESUMED, shard.id, replayed);
 };

src/sharding/ShardClientUtil.js

@@ -181,6 +181,11 @@ class ShardClientUtil {
   _respond(type, message) {
     this.send(message).catch(err => {
       err.message = `Error when sending ${type} response to master process: ${err.message}`;
+      /**
+       * Emitted when the client encounters an error.
+       * @event Client#error
+       * @param {Error} error The error encountered
+       */
       this.client.emit(Events.ERROR, err);
     });
   }

typings/index.d.ts

@@ -1339,7 +1339,7 @@ declare module 'discord.js' {
 		private connect(): Promise<void>;
 		private onOpen(): void;
 		private onMessage(event: MessageEvent): void;
-		private onError(error: ErrorEvent): void;
+		private onError(error: ErrorEvent | object): void;
 		private onClose(event: CloseEvent): void;
 		private onPacket(packet: object): void;
 		private setHelloTimeout(time?: number): void;