feat(listener): Add full support for ESM & Better typing

Signed-off-by: Florian Bouillon <f.bouillon@aptatio.com>

packages/listener/CHANGELOG.md

@@ -6,6 +6,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [1.1.0] - 2023-11-09
+
+### Added
+
+- Full support for both CJS & ESM
+
+### Changed
+
+- Better typing support
+
 ## [1.0.3] - 2022-11-17
 
 ### Fixed

packages/listener/Listener.ts

@@ -1,129 +1,155 @@
-type ItemToArray<T> = {
+type RecordToArray<T> = {
 	[P in keyof T]?: Array<T[P]>
 }
 
-type BuiltInEvents = {
+type EventList = Record<string, (...args: Array<any>) => void>
+
+type BaseEvents<T extends EventList = {}> = {
 	newListener: (eventName: string, listener: (...args: Array<any>) => void) => void
 	removeListener: (eventName: string, listener: (...args: Array<any>) => void) => void
 	all: (eventName: string, ...args: Array<any>) => void
-}
+} & T
 
-export default abstract class Listener<
+/**
-	T extends Record<string, (...args: Array<any>) => void> = BuiltInEvents
+ * Allows you to create a typed event handler system
+ */
+export default class Listener<
+	T extends EventList = BaseEvents
 > {
 
 	private maxListeners = 10
 
-	private handlers: ItemToArray<T> = {}
+	private handlers: RecordToArray<BaseEvents<T>> = {}
 
 	/**
 	 * Add a listener to the event
 	 * @param event the event name
 	 * @param listener the listener
+	 * @returns the class
 	 */
-	public addListener(event: keyof T, listener: T[typeof event]) {
+	public addListener<Key extends keyof BaseEvents<T>>(event: Key, listener: BaseEvents<T>[Key]): this {
 		return this.on(event, listener)
 	}
 
 	/**
 	 * Add a listener to the event
+	 *
 	 * @param event the event name
 	 * @param listener the listener
+	 *
+	 * @returns the class
 	 */
-	public on(event: keyof T, listener: T[typeof event]) {
+	public on<Key extends keyof BaseEvents<T>>(event: Key, listener: BaseEvents<T>[Key]): this {
 		return this.internalAdd(true, event, listener)
 	}
 
 	/**
 	 * Add a one time trigger listener to the event
+	 *
 	 * @param event the event name
 	 * @param listener the listener
+	 *
+	 * @returns the class
 	 */
-	public once(event: keyof T, listener: T[typeof event]) {
+	public once<Key extends keyof BaseEvents<T>>(event: Key, listener: BaseEvents<T>[Key]): this {
 		const fn = (...args: Array<any>) => {
 			listener(...args)
-			this.off(event, fn as any)
+			this.off(event, fn as BaseEvents<T>[Key])
 		}
-		this.on(event, fn as any)
+		return this.on(event, fn as BaseEvents<T>[Key])
-		return this
 	}
 
 	/**
 	 * remove a listener from the event
+	 *
 	 * @param event the event name
 	 * @param listener the listener
+	 *
+	 * @returns the class
 	 */
-	public removeListener(event: keyof T, listener: T[typeof event]) {
+	public removeListener<Key extends keyof BaseEvents<T>>(event: Key, listener: BaseEvents<T>[Key]): this {
 		return this.off(event, listener)
 	}
 
 	/**
 	 * remove a listener from the event
+	 *
 	 * @param event the event name
 	 * @param listener the listener
+	 *
+	 *
+	 * @returns the class
 	 */
-	public off(event: keyof T, listener: T[typeof event]) {
+	public off<Key extends keyof BaseEvents<T>>(event: Key, listener: BaseEvents<T>[Key]): this {
-		const listeners = this.listeners(event)
+		return this.internalRemove(event, listener)
-		const index = listeners.indexOf(listener)
-		if (index !== -1) {
-			(this.handlers[event] as Array<T[typeof event]>).splice(index, 1)
-		}
-
-		// @ts-expect-error Meta Listener
-		this.emit('removeListener', event, listener)
-		return this
 	}
 
 	/**
 	 * remove every listeners from the event
+	 *
 	 * @param event the event name
+	 *
+	 * @returns the class
 	 */
-	public removeAllListeners(event: keyof T) {
+	public removeAllListeners(event: keyof BaseEvents<T>): this {
-		const listeners = this.listeners(event)
+		return this.internalRemove(event)
-		listeners.forEach((ev) => this.off(event, ev))
+	}
+
+	/**
+	 * set a maximum number of listeners before sending a warning
+	 *
+	 * @param count the number of listeners before sending the warning
+	 *
+	 * @returns the class
+	 */
+	public setMaxListeners(count: number): this {
+		this.maxListeners = count
+
 		return this
 	}
 
-	/**
-	 * set a maximum numbre of listeners before sending a warning
-	 * @param n the number of listeners before sending the warning
-	 */
-	public setMaxListeners(n: number) {
-		this.maxListeners = n
-	}
-
 	/**
 	 * Return the current max number of listeners
+	 *
+	 * @returns the maximum number of listeners before it send warnings
 	 */
-	public getMaxListeners() {
+	public getMaxListeners(): number {
 		return this.maxListeners
 	}
 
 	/**
 	 * return every listeners from the event
+	 *
 	 * @param event the event name
+	 *
+	 * @returns the list of events
 	 */
-	public listeners(event: keyof T) {
+	public listeners<Key extends keyof BaseEvents<T>>(event: Key): Array<BaseEvents<T>[Key]> {
-		const item = this.handlers[event] as Array<T[typeof event]>
+		return this.handlers[event] ?? []
-		return item ?? []
 	}
 
 	/**
 	 * return every listeners from the event
+	 *
 	 * @param event the event name
+	 *
+	 * @returns the list of listenersattached to the event
 	 */
-	public rawListeners(event: keyof T) {
+	public rawListeners<Key extends keyof BaseEvents<T>>(event: Key): Array<BaseEvents<T>[Key]> {
-		return this.listenerCount(event)
+		return this.listeners(event)
 	}
 
 	/**
 	 * Emit the event with the selected variables
+	 *
 	 * @param event the event to emit
 	 * @param ev the variables to send
+	 *
+	 * @return if the evenet was emitted to any listeners or not
 	 */
-	public emit(event: keyof T, ...ev: Parameters<T[typeof event]>) {
+	public emit<Key extends keyof BaseEvents<T>>(event: Key, ...ev: Parameters<BaseEvents<T>[Key]>): boolean {
 		if (event !== 'all') {
-			// @ts-expect-error Meta Listener
+			// @ts-expect-error the all event is sent each time a new event is emitted
 			this.emit('all', event, ...ev)
 		}
 		const listeners = this.listeners(event)
@@ -133,27 +159,36 @@ export default abstract class Listener<
 
 	/**
 	 * return the number of events in the current event
+	 *
 	 * @param event the event
+	 *
+	 * @returns the number of listeners attached to the event
 	 */
-	public listenerCount(event: keyof T) {
+	public listenerCount(event: keyof BaseEvents<T>): number {
 		return this.listeners(event).length
 	}
 
 	/**
 	 * prepend the listener to the event list
+	 *
 	 * @param event the event
 	 * @param listener the listener to attach
+	 *
+	 * @returns the class
 	 */
-	public prependListener(event: keyof T, listener: T[typeof event]) {
+	public prependListener<Key extends keyof BaseEvents<T>>(event: Key, listener: BaseEvents<T>[Key]): this {
 		return this.internalAdd(false, event, listener)
 	}
 
 	/**
 	 * prepend the listener to the event list to triggered once
+	 *
 	 * @param event the event
 	 * @param listener the listener to attach
+	 *
+	 * @returns the class
 	 */
-	public prependOnceListener(event: keyof T, listener: T[typeof event]) {
+	public prependOnceListener<Key extends keyof BaseEvents<T>>(event: Key, listener: BaseEvents<T>[Key]): this {
 		const fn = (...args: Parameters<typeof listener>) => {
 			listener(...args)
 			this.off(event, fn as any)
@@ -164,22 +199,39 @@ export default abstract class Listener<
 
 	/**
 	 * get every event names with at least one event
+	 *
+	 * @returns the list of events keys
 	 */
-	public eventNames() {
+	public eventNames(): Array<keyof BaseEvents<T>> {
 		return Object.keys(this.handlers)
 	}
 
-	// Browser Listeners
+	/**
-	public addEventListener(event: keyof T, listener: T[typeof event]) {
+	 * Add a listener to the event
+	 *
+	 * @param event the event name
+	 * @param listener the listener
+	 *
+	 * @returns the class
+	 */
+	public addEventListener<Key extends keyof BaseEvents<T>>(event: Key, listener: BaseEvents<T>[Key]): this {
 		return this.on(event, listener)
 	}
 
-	public removeEventListener(event: keyof T, listener: T[typeof event]) {
+	/**
+	 * remove a listener from the event
+	 *
+	 * @param event the event name
+	 * @param listener the listener
+	 *
+	 * @returns the class
+	 */
+	public removeEventListener<Key extends keyof BaseEvents<T>>(event: Key, listener: BaseEvents<T>[Key]): this {
 		return this.off(event, listener)
 	}
 
-	private internalAdd(push: boolean, event: keyof T, listener: T[typeof event]) {
+	private internalAdd<Key extends keyof BaseEvents<T>>(push: boolean, event: Key, listener: BaseEvents<T>[Key]): this {
-		// @ts-expect-error Meta Listener
+		// @ts-expect-error Meta Listener that emit when a new event is addrd
 		this.emit('newListener', event, listener)
 		const item = this.handlers[event]
 		if (!item) {
@@ -193,8 +245,25 @@ export default abstract class Listener<
 		}
 		const listenerCount = this.listenerCount(event)
 		if (listenerCount > this.getMaxListeners()) {
-			console.warn(`MaxListenersExceededWarning: Possible EventEmitter memory leak detected. ${this.getMaxListeners()} listeners recommended while there is ${listenerCount} listeners. Use emitter.setMaxListeners() to increase limit`)
+			console.warn(`MaxListenersExceededWarning: Possible Listener memory leak detected. ${this.getMaxListeners()} listeners recommended while there is ${listenerCount} listeners. Use setMaxListeners() to increase the limit`)
 		}
 		return this
 	}
+
+	private internalRemove<Key extends keyof BaseEvents<T>>(event: Key, listener?: BaseEvents<T>[Key]): this {
+		if (!listener) {
+			for (const listener of (this.handlers[event] ?? [])) {
+				this.internalRemove(event, listener)
+			}
+			return this
+		}
+		const listeners = this.listeners(event)
+		const idx = listeners.indexOf(listener)
+		if (idx >= 0) {
+			this.handlers[event]?.splice(idx, 1)
+		}
+		// @ts-expect-error Meta Listener that emit when a event is removed
+		this.emit('removeListener', event, listener)
+		return this
+	}
 }

packages/listener/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@dzeio/listener",
-	"version": "1.0.3",
+	"version": "1.1.0",
 	"description": "A NodeJS Listener implementation",
 	"repository": {
 		"type": "git",
@@ -10,9 +10,28 @@
 	"author": "Aviortheking",
 	"license": "MIT",
 	"main": "./dist/Listener.js",
+	"module": "./dist/Listener.mjs",
 	"types": "./dist/Listener.d.ts",
+	"browser": "./dist/Listener.global.js",
+	"exports": {
+		".": {
+			"require": {
+				"types": "./dist/Listener.d.ts",
+				"default": "./dist/Listener.js"
+			},
+			"import": {
+				"types": "./dist/Listener.d.mts",
+				"default": "./dist/Listener.mjs"
+			}
+		}
+	},
+	"files": ["dist"],
 	"scripts": {
 		"prepublishOnly": "npm run build",
-		"build": "tsc"
+		"build": "tsup ./Listener.ts --format cjs,esm --dts --clean && tsup ./Listener.ts --format iife --global-name Listener --minify --sourcemap"
+	},
+	"devDependencies": {
+		"tsup": "^7.2.0",
+		"typescript": "^5.2.2"
 	}
 }