State Pattern

class Red {
  constructor(light) {
    this.light = light;
    this.light.onRedLight();
  }

  next() {
    this.light.setState(new Green(this.light));
  }
}

class Yellow {
  constructor(light) {
    this.light = light;
    this.light.onYellowLight();
  }

  next() {
    this.light.setState(new Red(this.light));
  }
}

class Green {
  constructor(light) {
    this.light = light;
    this.light.onGreenLight();
  }

  next() {
    this.light.setState(new Yellow(this.light));
  }
}

class TrafficLight {
  constructor() {
    this.currentState = new Red(this);
  }

  setState(state) {
    this.currentState = state;
  }

  onRedLight() {
    console.log('Red State');
  }

  onYellowLight() {
    console.log('Yellow State');
  }

  onGreenLight() {
    console.log('Green State');
  }

  next() {
    this.currentState.next();
  }
}

const trafficLight = new TrafficLight(); // Red State
trafficLight.next(); // Green State
trafficLight.next(); // Yellow State
trafficLight.next(); // Red State