单元测试蛇游戏

// snake.js
class Snake {
  constructor() {
    this.body = [{ x: 0, y: 0 }];
    this.direction = 'right';
  }

  move() {
    const head = { ...this.body[0] };
    switch (this.direction) {
      case 'up':
        head.y -= 1;
        break;
      case 'down':
        head.y += 1;
        break;
      case 'left':
        head.x -= 1;
        break;
      case 'right':
        head.x += 1;
        break;
    }
    this.body.unshift(head);
    this.body.pop();
  }
}

module.exports = Snake;

// snake.test.js
const Snake = require('./snake');

test('Snake moves right', () => {
  const snake = new Snake();
  snake.move();
  expect(snake.body[0]).toEqual({ x: 1, y: 0 });
});

test('Snake moves left', () => {
  const snake = new Snake();
  snake.direction = 'left';
  snake.move();
  expect(snake.body[0]).toEqual({ x: -1, y: 0 });
});

// 其他方向的测试用例...