Node : Création d'un EventEmitter

MyEventEmitter.js

class EventEmitter {
  constructor() {
    this.events = {};
  }

  on(eventName, listener) {
    this.events[eventName] = this.events[eventName] || [];
    this.events[eventName].push(listener);
  }

  once(eventName, listener) {
    listener.once = true;
    this.on(eventName, listener);
  }

  emit(eventName, ...args) {
    const eventListeners = this.events[eventName];
    
    if (eventListeners) {
      eventListeners.forEach((listener) => listener(...args));
      eventListeners.forEach((listener, index) => {
        if (listener.once) {
          eventListeners.splice(index, 1);
        }
      });
    }
  }
}