Command.js

// Command is a behavioral design pattern.
// Команда - поведенческий шаблон проектирования.

class Driver {
  constructor(command) {
    this.command = command;
  }

  execute() {
    this.command.execute();
  }
}

class Engine {
  constructor() {
    this.state = false;
  }

  on() {
    this.state = true;
  }

  off() {
    this.state = false;
  }
}

class StartCommand {
  constructor(engine) {
    this.engine = engine;
  }

  execute() {
    this.engine.on();
  }
}

class SwitchOffCommand {
  constructor(engine) {
    this.engine = engine;
  }

  execute() {
    this.engine.off();
  }
}

const engine = new Engine();
console.log(engine);

const startCommand = new StartCommand(engine);
const driver = new Driver(startCommand);
driver.execute();

console.log(engine);