refactor!: use AsyncEventEmitter instead of EventEmitter

BREAKING CHANGE: The `BaseClient`, `Shard`, `ShardingManager`, and `Collector` classes now extend `AsyncEventEmitter` instead of `EventEmitter`.

packages/discord.js/package.json

@@ -72,6 +72,7 @@
     "@discordjs/util": "workspace:^",
     "@discordjs/ws": "workspace:^",
     "@sapphire/snowflake": "3.5.5",
+    "@vladfrangu/async_event_emitter": "^2.4.6",
     "discord-api-types": "^0.37.114",
     "fast-deep-equal": "3.1.3",
     "lodash.snakecase": "4.1.1",

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

@@ -1,19 +1,19 @@
 'use strict';
 
-const EventEmitter = require('node:events');
 const { REST } = require('@discordjs/rest');
+const { AsyncEventEmitter } = require('@vladfrangu/async_event_emitter');
 const { Routes } = require('discord-api-types/v10');
 const { DiscordjsTypeError, ErrorCodes } = require('../errors');
 const { Options } = require('../util/Options');
 const { flatten } = require('../util/Util');
 
 /**
  * The base class for all clients.
- * @extends {EventEmitter}
+ * @extends {AsyncEventEmitter}
  */
-class BaseClient extends EventEmitter {
+class BaseClient extends AsyncEventEmitter {
   constructor(options = {}) {
-    super({ captureRejections: true });
+    super();
 
     if (typeof options !== 'object' || options === null) {
       throw new DiscordjsTypeError(ErrorCodes.InvalidType, 'options', 'object', true);

packages/discord.js/src/sharding/Shard.js

@@ -1,11 +1,11 @@
 'use strict';
 
-const EventEmitter = require('node:events');
 const path = require('node:path');
 const process = require('node:process');
 const { setTimeout, clearTimeout } = require('node:timers');
 const { setTimeout: sleep } = require('node:timers/promises');
 const { SHARE_ENV } = require('node:worker_threads');
+const { AsyncEventEmitter } = require('@vladfrangu/async_event_emitter');
 const { DiscordjsError, ErrorCodes } = require('../errors');
 const { ShardEvents } = require('../util/ShardEvents');
 const { makeError, makePlainError } = require('../util/Util');
@@ -17,9 +17,9 @@ let Worker = null;
  * A self-contained shard created by the {@link ShardingManager}. Each one has a {@link ChildProcess} that contains
  * an instance of the bot and its {@link Client}. When its child process/worker exits for any reason, the shard will
  * spawn a new one to replace it as necessary.
- * @extends {EventEmitter}
+ * @extends {AsyncEventEmitter}
  */
-class Shard extends EventEmitter {
+class Shard extends AsyncEventEmitter {
   constructor(manager, id) {
     super();
 
@@ -445,7 +445,7 @@ class Shard extends EventEmitter {
 
   /**
    * Increments max listeners by one for a given emitter, if they are not zero.
-   * @param {EventEmitter|process} emitter The emitter that emits the events.
+   * @param {Worker|ChildProcess} emitter The emitter that emits the events.
    * @private
    */
   incrementMaxListeners(emitter) {
@@ -457,7 +457,7 @@ class Shard extends EventEmitter {
 
   /**
    * Decrements max listeners by one for a given emitter, if they are not zero.
-   * @param {EventEmitter|process} emitter The emitter that emits the events.
+   * @param {Worker|ChildProcess} emitter The emitter that emits the events.
    * @private
    */
   decrementMaxListeners(emitter) {

packages/discord.js/src/sharding/ShardClientUtil.js

@@ -242,7 +242,7 @@ class ShardClientUtil {
 
   /**
    * Increments max listeners by one for a given emitter, if they are not zero.
-   * @param {EventEmitter|process} emitter The emitter that emits the events.
+   * @param {Worker|ChildProcess} emitter The emitter that emits the events.
    * @private
    */
   incrementMaxListeners(emitter) {
@@ -254,7 +254,7 @@ class ShardClientUtil {
 
   /**
    * Decrements max listeners by one for a given emitter, if they are not zero.
-   * @param {EventEmitter|process} emitter The emitter that emits the events.
+   * @param {Worker|ChildProcess} emitter The emitter that emits the events.
    * @private
    */
   decrementMaxListeners(emitter) {

packages/discord.js/src/sharding/ShardingManager.js

@@ -1,11 +1,11 @@
 'use strict';
 
-const EventEmitter = require('node:events');
 const fs = require('node:fs');
 const path = require('node:path');
 const process = require('node:process');
 const { setTimeout: sleep } = require('node:timers/promises');
 const { Collection } = require('@discordjs/collection');
+const { AsyncEventEmitter } = require('@vladfrangu/async_event_emitter');
 const { Shard } = require('./Shard');
 const { DiscordjsError, DiscordjsTypeError, DiscordjsRangeError, ErrorCodes } = require('../errors');
 const { fetchRecommendedShardCount } = require('../util/Util');
@@ -17,9 +17,9 @@ const { fetchRecommendedShardCount } = require('../util/Util');
  * process, and there are several useful methods that utilize it in order to simplify tasks that are normally difficult
  * with sharding. It can spawn a specific number of shards or the amount that Discord suggests for the bot, and takes a
  * path to your main bot script to launch for each one.
- * @extends {EventEmitter}
+ * @extends {AsyncEventEmitter}
  */
-class ShardingManager extends EventEmitter {
+class ShardingManager extends AsyncEventEmitter {
   /**
    * The mode to spawn shards with for a {@link ShardingManager}. Can be either one of:
    * * 'process' to use child processes

packages/discord.js/src/structures/interfaces/Collector.js

@@ -1,8 +1,8 @@
 'use strict';
 
-const EventEmitter = require('node:events');
 const { setTimeout, clearTimeout } = require('node:timers');
 const { Collection } = require('@discordjs/collection');
+const { AsyncEventEmitter } = require('@vladfrangu/async_event_emitter');
 const { DiscordjsTypeError, ErrorCodes } = require('../../errors');
 const { flatten } = require('../../util/Util');
 
@@ -25,10 +25,10 @@ const { flatten } = require('../../util/Util');
 
 /**
  * Abstract class for defining a new Collector.
- * @extends {EventEmitter}
+ * @extends {AsyncEventEmitter}
  * @abstract
  */
-class Collector extends EventEmitter {
+class Collector extends AsyncEventEmitter {
   constructor(client, options = {}) {
     super();
 

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

@@ -20,6 +20,7 @@ import { Awaitable, JSONEncodable } from '@discordjs/util';
 import { Collection, ReadonlyCollection } from '@discordjs/collection';
 import { BaseImageURLOptions, ImageURLOptions, RawFile, REST, RESTOptions } from '@discordjs/rest';
 import { WebSocketManager, WebSocketManagerOptions } from '@discordjs/ws';
+import { AsyncEventEmitter } from '@vladfrangu/async_event_emitter';
 import {
   APIActionRowComponent,
   APIApplicationCommandInteractionData,
@@ -177,7 +178,6 @@ import {
   GatewayVoiceChannelEffectSendDispatchData,
 } from 'discord-api-types/v10';
 import { ChildProcess } from 'node:child_process';
-import { EventEmitter } from 'node:events';
 import { Stream } from 'node:stream';
 import { MessagePort, Worker } from 'node:worker_threads';
 import {
@@ -515,7 +515,7 @@ export abstract class Base {
   public valueOf(): string;
 }
 
-export class BaseClient extends EventEmitter implements AsyncDisposable {
+export class BaseClient<Events extends {}> extends AsyncEventEmitter<Events> implements AsyncDisposable {
   public constructor(options?: ClientOptions | WebhookClientOptions);
   private decrementMaxListeners(): void;
   private incrementMaxListeners(): void;
@@ -959,7 +959,7 @@ export type If<Value extends boolean, TrueResult, FalseResult = null> = Value ex
     ? FalseResult
     : TrueResult | FalseResult;
 
-export class Client<Ready extends boolean = boolean> extends BaseClient {
+export class Client<Ready extends boolean = boolean> extends BaseClient<ClientEvents> {
   public constructor(options: ClientOptions);
   private actions: unknown;
   private expectedGuilds: Set<Snowflake>;
@@ -977,18 +977,6 @@ 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[]>;
-
   public application: If<Ready, ClientApplication>;
   public channels: ChannelManager;
   public get emojis(): BaseGuildEmojiManager;
@@ -1023,30 +1011,6 @@ export class Client<Ready extends boolean = boolean> extends BaseClient {
   public login(token?: string): Promise<string>;
   public isReady(): this is Client<true>;
   public toJSON(): unknown;
-
-  public on<Event extends keyof ClientEvents>(event: Event, listener: (...args: ClientEvents[Event]) => void): this;
-  public on<Event extends string | symbol>(
-    event: Exclude<Event, keyof ClientEvents>,
-    listener: (...args: any[]) => void,
-  ): this;
-
-  public once<Event extends keyof ClientEvents>(event: Event, listener: (...args: ClientEvents[Event]) => void): this;
-  public once<Event extends string | symbol>(
-    event: Exclude<Event, keyof ClientEvents>,
-    listener: (...args: any[]) => void,
-  ): this;
-
-  public emit<Event extends keyof ClientEvents>(event: Event, ...args: ClientEvents[Event]): boolean;
-  public emit<Event extends string | symbol>(event: Exclude<Event, keyof ClientEvents>, ...args: unknown[]): boolean;
-
-  public off<Event extends keyof ClientEvents>(event: Event, listener: (...args: ClientEvents[Event]) => void): this;
-  public off<Event extends string | symbol>(
-    event: Exclude<Event, keyof ClientEvents>,
-    listener: (...args: any[]) => void,
-  ): this;
-
-  public removeAllListeners<Event extends keyof ClientEvents>(event?: Event): this;
-  public removeAllListeners<Event extends string | symbol>(event?: Exclude<Event, keyof ClientEvents>): this;
 }
 
 export interface StickerPackFetchOptions {
@@ -1134,7 +1098,9 @@ export interface CollectorEventTypes<Key, Value, Extras extends unknown[] = []>
   end: [collected: ReadonlyCollection<Key, Value>, reason: string];
 }
 
-export abstract class Collector<Key, Value, Extras extends unknown[] = []> extends EventEmitter {
+export abstract class Collector<Key, Value, Extras extends unknown[] = []> extends AsyncEventEmitter<
+  CollectorEventTypes<Key, Value, Extras>
+> {
   protected constructor(client: Client<true>, options?: CollectorOptions<[Value, ...Extras]>);
   private _timeout: NodeJS.Timeout | null;
   private _idletimeout: NodeJS.Timeout | null;
@@ -1160,16 +1126,6 @@ export abstract class Collector<Key, Value, Extras extends unknown[] = []> exten
   protected listener: (...args: any[]) => void;
   public abstract collect(...args: unknown[]): Awaitable<Key | null>;
   public abstract dispose(...args: unknown[]): Key | null;
-
-  public on<EventKey extends keyof CollectorEventTypes<Key, Value, Extras>>(
-    event: EventKey,
-    listener: (...args: CollectorEventTypes<Key, Value, Extras>[EventKey]) => void,
-  ): this;
-
-  public once<EventKey extends keyof CollectorEventTypes<Key, Value, Extras>>(
-    event: EventKey,
-    listener: (...args: CollectorEventTypes<Key, Value, Extras>[EventKey]) => void,
-  ): this;
 }
 
 export class ChatInputCommandInteraction<Cached extends CacheType = CacheType> extends CommandInteraction<Cached> {
@@ -2031,19 +1987,6 @@ export class InteractionCollector<Interaction extends CollectedInteraction> exte
   public collect(interaction: Interaction): Snowflake;
   public empty(): void;
   public dispose(interaction: Interaction): Snowflake;
-  public on(event: 'collect' | 'dispose' | 'ignore', listener: (interaction: Interaction) => void): this;
-  public on(
-    event: 'end',
-    listener: (collected: ReadonlyCollection<Snowflake, Interaction>, reason: string) => void,
-  ): this;
-  public on(event: string, listener: (...args: any[]) => void): this;
-
-  public once(event: 'collect' | 'dispose' | 'ignore', listener: (interaction: Interaction) => void): this;
-  public once(
-    event: 'end',
-    listener: (collected: ReadonlyCollection<Snowflake, Interaction>, reason: string) => void,
-  ): this;
-  public once(event: string, listener: (...args: any[]) => void): this;
 }
 
 // tslint:disable-next-line no-empty-interface
@@ -2783,26 +2726,6 @@ export class ReactionCollector extends Collector<Snowflake | string, MessageReac
   public collect(reaction: MessageReaction, user: User): Snowflake | string | null;
   public dispose(reaction: MessageReaction, user: User): Snowflake | string | null;
   public empty(): void;
-
-  public on(
-    event: 'collect' | 'dispose' | 'remove' | 'ignore',
-    listener: (reaction: MessageReaction, user: User) => void,
-  ): this;
-  public on(
-    event: 'end',
-    listener: (collected: ReadonlyCollection<Snowflake, MessageReaction>, reason: string) => void,
-  ): this;
-  public on(event: string, listener: (...args: any[]) => void): this;
-
-  public once(
-    event: 'collect' | 'dispose' | 'remove' | 'ignore',
-    listener: (reaction: MessageReaction, user: User) => void,
-  ): this;
-  public once(
-    event: 'end',
-    listener: (collected: ReadonlyCollection<Snowflake, MessageReaction>, reason: string) => void,
-  ): this;
-  public once(event: string, listener: (...args: any[]) => void): this;
 }
 
 export class ReactionEmoji extends Emoji {
@@ -2997,15 +2920,15 @@ export interface ShardEventTypes {
   spawn: [process: ChildProcess | Worker];
 }
 
-export class Shard extends EventEmitter {
+export class Shard extends AsyncEventEmitter<ShardEventTypes> {
   private constructor(manager: ShardingManager, id: number);
   private _evals: Map<string, Promise<unknown>>;
   private _exitListener: (...args: any[]) => void;
   private _fetches: Map<string, Promise<unknown>>;
   private _handleExit(respawn?: boolean, timeout?: number): void;
   private _handleMessage(message: unknown): void;
-  private incrementMaxListeners(emitter: EventEmitter | ChildProcess): void;
-  private decrementMaxListeners(emitter: EventEmitter | ChildProcess): void;
+  private incrementMaxListeners(emitter: Worker | ChildProcess): void;
+  private decrementMaxListeners(emitter: Worker | ChildProcess): void;
 
   public args: string[];
   public execArgv: string[];
@@ -3027,24 +2950,14 @@ export class Shard extends EventEmitter {
   public respawn(options?: { delay?: number; timeout?: number }): Promise<ChildProcess>;
   public send(message: unknown): Promise<Shard>;
   public spawn(timeout?: number): Promise<ChildProcess>;
-
-  public on<Event extends keyof ShardEventTypes>(
-    event: Event,
-    listener: (...args: ShardEventTypes[Event]) => void,
-  ): this;
-
-  public once<Event extends keyof ShardEventTypes>(
-    event: Event,
-    listener: (...args: ShardEventTypes[Event]) => void,
-  ): this;
 }
 
 export class ShardClientUtil {
   private constructor(client: Client<true>, mode: ShardingManagerMode);
   private _handleMessage(message: unknown): void;
   private _respond(type: string, message: unknown): void;
-  private incrementMaxListeners(emitter: EventEmitter | ChildProcess): void;
-  private decrementMaxListeners(emitter: EventEmitter | ChildProcess): void;
+  private incrementMaxListeners(emitter: Worker | ChildProcess): void;
+  private decrementMaxListeners(emitter: Worker | ChildProcess): void;
 
   public client: Client;
   public get count(): number;
@@ -3073,7 +2986,11 @@ export class ShardClientUtil {
   public static shardIdForGuildId(guildId: Snowflake, shardCount: number): number;
 }
 
-export class ShardingManager extends EventEmitter {
+export interface ShardingManagerEvents {
+  shardCreate: [shard: Shard];
+}
+
+export class ShardingManager extends AsyncEventEmitter<ShardingManagerEvents> {
   public constructor(file: string, options?: ShardingManagerOptions);
   private _performOnShards(method: string, args: readonly unknown[]): Promise<unknown[]>;
   private _performOnShards(method: string, args: readonly unknown[], shard: number): Promise<unknown>;
@@ -3105,10 +3022,6 @@ export class ShardingManager extends EventEmitter {
   public fetchClientValues(prop: string, shard: number): Promise<unknown>;
   public respawnAll(options?: MultipleShardRespawnOptions): Promise<Collection<number, Shard>>;
   public spawn(options?: MultipleShardSpawnOptions): Promise<Collection<number, Shard>>;
-
-  public on(event: 'shardCreate', listener: (shard: Shard) => void): this;
-
-  public once(event: 'shardCreate', listener: (shard: Shard) => void): this;
 }
 
 export interface FetchRecommendedShardCountOptions {
@@ -3692,8 +3605,8 @@ export class Webhook<Type extends WebhookType = WebhookType> {
 }
 
 // tslint:disable-next-line no-empty-interface
-export interface WebhookClient extends WebhookFields, BaseClient {}
-export class WebhookClient extends BaseClient {
+export interface WebhookClient extends WebhookFields, BaseClient<{}> {}
+export class WebhookClient extends BaseClient<{}> {
   public constructor(data: WebhookClientData, options?: WebhookClientOptions);
   public readonly client: this;
   public options: WebhookClientOptions;

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

@@ -1306,9 +1306,9 @@ client.on('guildCreate', async g => {
   );
 });
 
-// EventEmitter static method overrides
+// Event emitter static method overrides
 expectType<Promise<[Client<true>]>>(Client.once(client, 'clientReady'));
-expectType<AsyncIterableIterator<[Client<true>]>>(Client.on(client, 'clientReady'));
+expectAssignable<AsyncIterableIterator<[Client<true>]>>(Client.on(client, 'clientReady'));
 
 client.login('absolutely-valid-token');