feat(Client): add typed wrapper methods for EventEmitter.{on,once}

packages/discord.js/src/client/BaseClient.js

@@ -103,6 +103,26 @@ class BaseClient extends EventEmitter {
     }
   }
 
+  /**
+   * Shorthand for `EventEmitter.on(client, ...)`
+   * @param {string} eventName The name of the client event to listen for
+   * @param {Object} [options] Passed as the `options` argument to `EventEmitter.on()`
+   * @returns {AsyncIterator} An async iterator that yields on each emitted event
+   */
+  eventIterator(eventName, options = {}) {
+    return super.constructor.on(this, eventName, options);
+  }
+
+  /**
+   * Shorthand for `EventEmitter.once(client, ...)`
+   * @param {string} eventName The name of the client event to listen for
+   * @param {Object} [options] Passed as the `options` argument to `EventEmitter.once()`
+   * @returns {Promise<Array<*>>} A promise that resolves to the next emitted event
+   */
+  awaitEvent(eventName, options = {}) {
+    return super.constructor.once(this, eventName, options);
+  }
+
   toJSON(...props) {
     return flatten(this, ...props);
   }

packages/discord.js/typings/index.d.ts

@@ -168,7 +168,7 @@ import {
   GatewayDispatchPayload,
 } from 'discord-api-types/v10';
 import { ChildProcess } from 'node:child_process';
-import { EventEmitter } from 'node:events';
+import { Abortable, EventEmitter } from 'node:events';
 import { Stream } from 'node:stream';
 import { MessagePort, Worker } from 'node:worker_threads';
 import {
@@ -512,6 +512,8 @@ export class BaseClient extends EventEmitter implements AsyncDisposable {
   public options: ClientOptions | WebhookClientOptions;
   public rest: REST;
   public destroy(): void;
+  public eventIterator(eventName: string | symbol, options?: Abortable): AsyncIterableIterator<any[]>;
+  public awaitEvent(eventName: string | symbol, options?: Abortable): Promise<any[]>;
   public toJSON(...props: Record<string, boolean | string>[]): unknown;
   public [Symbol.asyncDispose](): Promise<void>;
 }
@@ -967,17 +969,17 @@ export class Client<Ready extends boolean = boolean> extends BaseClient {
   // This a technique used to brand the ready state. Or else we'll get `never` errors on typeguard checks.
   private readonly _ready: Ready;
 
-  // Override inherited static EventEmitter methods, with added type checks for Client events.
-  public static once<Emitter extends EventEmitter, Event extends keyof ClientEvents>(
-    eventEmitter: Emitter,
-    eventName: Emitter extends Client ? Event : string | symbol,
-    options?: { signal?: AbortSignal | undefined },
-  ): Promise<Emitter extends Client ? ClientEvents[Event] : any[]>;
-  public static on<Emitter extends EventEmitter, Event extends keyof ClientEvents>(
-    eventEmitter: Emitter,
-    eventName: Emitter extends Client ? Event : string | symbol,
-    options?: { signal?: AbortSignal | undefined },
-  ): AsyncIterableIterator<Emitter extends Client ? ClientEvents[Event] : any[]>;
+  // Overloads for BaseClient's EventEmitter static method wrappers, with ClientEvents-aware typings.
+  public eventIterator<Event extends keyof ClientEvents>(
+    eventName: Event,
+    options?: Abortable,
+  ): AsyncIterableIterator<ClientEvents[Event]>;
+  public eventIterator(eventName: string | symbol, options?: Abortable): AsyncIterableIterator<any[]>;
+  public awaitEvent<Event extends keyof ClientEvents>(
+    eventName: Event,
+    options?: Abortable,
+  ): Promise<ClientEvents[Event]>;
+  public awaitEvent(eventName: string | symbol, options?: Abortable): Promise<any[]>;
 
   public application: If<Ready, ClientApplication>;
   public channels: ChannelManager;

packages/discord.js/typings/index.test-d.ts

@@ -1301,9 +1301,11 @@ client.on('guildCreate', async g => {
   );
 });
 
-// EventEmitter static method overrides
-expectType<Promise<[Client<true>]>>(Client.once(client, 'clientReady'));
-expectType<AsyncIterableIterator<[Client<true>]>>(Client.on(client, 'clientReady'));
+// EventEmitter static method wrappers
+expectType<Promise<[Client<true>]>>(client.awaitEvent('clientReady'));
+expectType<Promise<any[]>>(client.awaitEvent('unknownEvent'));
+expectType<AsyncIterableIterator<[Client<true>]>>(client.eventIterator('clientReady'));
+expectType<AsyncIterableIterator<any[]>>(client.eventIterator('unknownEvent'));
 
 client.login('absolutely-valid-token');