From c53ccd3bbcdda62bee33289b2ead5996161a4e80 Mon Sep 17 00:00:00 2001 From: Jared Wray Date: Mon, 14 Oct 2024 12:20:40 -0700 Subject: [PATCH] adding in event emitter type --- src/event-emitter-type.ts | 156 ++++++++++++++++++++++++++++++++++++++ vitest.config.ts | 1 + 2 files changed, 157 insertions(+) create mode 100644 src/event-emitter-type.ts diff --git a/src/event-emitter-type.ts b/src/event-emitter-type.ts new file mode 100644 index 0000000..1fd3a94 --- /dev/null +++ b/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; + + /** + * 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; +}; diff --git a/vitest.config.ts b/vitest.config.ts index ecf0f35..89275b9 100644 --- a/vitest.config.ts +++ b/vitest.config.ts @@ -9,6 +9,7 @@ export default defineConfig({ 'vitest.config.ts', 'dist/**', 'test/**', + 'src/event-emitter-type.ts', ], }, },