adding in event emitter type

src/event-emitter-type.ts

@@ -0,0 +1,156 @@
+type EventEmitterType = {
+	/**
+	 * Registers a listener for the specified event.
+	 *
+	 * @param eventName - The name (or symbol) of the event to listen for.
+	 * @param listener - A callback function that will be invoked when the event is emitted.
+	 * @returns The current instance of EventEmitter for method chaining.
+	 *
+	 * @example
+	 * emitter.on('data', (message) => {
+	 *   console.log(message);
+	 * });
+	 */
+	on(eventName: string | symbol, listener: (...arguments_: any[]) => void): EventEmitterType;
+
+	/**
+	 * Alias for `on`. Registers a listener for the specified event.
+	 *
+	 * @param eventName - The name (or symbol) of the event to listen for.
+	 * @param listener - A callback function that will be invoked when the event is emitted.
+	 * @returns The current instance of EventEmitter for method chaining.
+	 */
+	addListener(eventName: string | symbol, listener: (...arguments_: any[]) => void): EventEmitterType;
+
+	/**
+	 * Registers a one-time listener for the specified event. The listener is removed after it is called once.
+	 *
+	 * @param eventName - The name (or symbol) of the event to listen for.
+	 * @param listener - A callback function that will be invoked once when the event is emitted.
+	 * @returns The current instance of EventEmitter for method chaining.
+	 *
+	 * @example
+	 * emitter.once('close', () => {
+	 *   console.log('The connection was closed.');
+	 * });
+	 */
+	once(eventName: string | symbol, listener: (...arguments_: any[]) => void): EventEmitterType;
+
+	/**
+	 * Removes a previously registered listener for the specified event.
+	 *
+	 * @param eventName - The name (or symbol) of the event to stop listening for.
+	 * @param listener - The specific callback function to remove.
+	 * @returns The current instance of EventEmitter for method chaining.
+	 *
+	 * @example
+	 * emitter.off('data', myListener);
+	 */
+	off(eventName: string | symbol, listener: (...arguments_: any[]) => void): EventEmitterType;
+
+	/**
+	 * Alias for `off`. Removes a previously registered listener for the specified event.
+	 *
+	 * @param eventName - The name (or symbol) of the event to stop listening for.
+	 * @param listener - The specific callback function to remove.
+	 * @returns The current instance of EventEmitter for method chaining.
+	 */
+	removeListener(eventName: string | symbol, listener: (...arguments_: any[]) => void): EventEmitterType;
+
+	/**
+	 * Emits the specified event, invoking all registered listeners with the provided arguments.
+	 *
+	 * @param eventName - The name (or symbol) of the event to emit.
+	 * @param args - Arguments passed to each listener.
+	 * @returns `true` if the event had listeners, `false` otherwise.
+	 *
+	 * @example
+	 * emitter.emit('data', 'Hello World');
+	 */
+	emit(eventName: string | symbol, ...arguments_: any[]): boolean;
+
+	/**
+	 * Returns the number of listeners registered for the specified event.
+	 *
+	 * @param eventName - The name (or symbol) of the event.
+	 * @returns The number of registered listeners.
+	 *
+	 * @example
+	 * const count = emitter.listenerCount('data');
+	 * console.log(count); // e.g., 2
+	 */
+	listenerCount(eventName: string | symbol): number;
+
+	/**
+	 * Removes all listeners for the specified event. If no event is specified, it removes all listeners for all events.
+	 *
+	 * @param eventName - (Optional) The name (or symbol) of the event.
+	 * @returns The current instance of EventEmitter for method chaining.
+	 *
+	 * @example
+	 * emitter.removeAllListeners('data');
+	 */
+	removeAllListeners(eventName?: string | symbol): EventEmitterType;
+
+	/**
+	 * Returns an array of event names for which listeners have been registered.
+	 *
+	 * @returns An array of event names (or symbols).
+	 *
+	 * @example
+	 * const events = emitter.eventNames();
+	 * console.log(events); // e.g., ['data', 'close']
+	 */
+	eventNames(): Array<string | symbol>;
+
+	/**
+	 * Returns an array of listeners registered for the specified event.
+	 *
+	 * @param eventName - The name (or symbol) of the event.
+	 * @returns An array of listener functions.
+	 *
+	 * @example
+	 * const listeners = emitter.listeners('data');
+	 * console.log(listeners.length); // e.g., 2
+	 */
+	listeners(eventName: string | symbol): Array<(...arguments_: any[]) => void>;
+
+	/**
+	 * Returns an array of raw listeners for the specified event. This includes listeners wrapped by internal mechanisms (e.g., once-only listeners).
+	 *
+	 * @param eventName - The name (or symbol) of the event.
+	 * @returns An array of raw listener functions.
+	 *
+	 * @example
+	 * const rawListeners = emitter.rawListeners('data');
+	 */
+	rawListeners(eventName: string | symbol): Array<(...arguments_: any[]) => void>;
+
+	/**
+	 * Adds a listener to the beginning of the listeners array for the specified event.
+	 *
+	 * @param eventName - The name (or symbol) of the event to listen for.
+	 * @param listener - A callback function that will be invoked when the event is emitted.
+	 * @returns The current instance of EventEmitter for method chaining.
+	 *
+	 * @example
+	 * emitter.prependListener('data', (message) => {
+	 *   console.log('This will run first.');
+	 * });
+	 */
+	prependListener(eventName: string | symbol, listener: (...arguments_: any[]) => void): EventEmitterType;
+
+	/**
+	 * Adds a one-time listener to the beginning of the listeners array for the specified event.
+	 *
+	 * @param eventName - The name (or symbol) of the event to listen for.
+	 * @param listener - A callback function that will be invoked once when the event is emitted.
+	 * @returns The current instance of EventEmitter for method chaining.
+	 *
+	 * @example
+	 * emitter.prependOnceListener('data', (message) => {
+	 *   console.log('This will run first and only once.');
+	 * });
+	 */
+	prependOnceListener(eventName: string | symbol, listener: (...arguments_: any[]) => void): EventEmitterType;
+};

vitest.config.ts

@@ -9,6 +9,7 @@ export default defineConfig({
 				'vitest.config.ts',
 				'dist/**',
 				'test/**',
+				'src/event-emitter-type.ts',
 			],
 		},
 	},