消息提示队列处理，避免消息文字显示重叠

// 消息提示队列
// 同时有多个api返回失败消息的时候，以队列方式依次显示，避免消息文字显示重叠
const toastQueue = {
  queue: [],
  instance: null,
  enq(message, options = null) {
    this.queue.push({ message, options });
    this.next();
  },
  next() {
    if (this.instance || !this.queue.length) return;

    const { message, options } = this.queue.shift();
    this.instance = Toast(message, options);
    this.instance.$on('close', () => {
      this.instance = null;
      this.next();
    });
  },
};


// 调用
toastQueue.enq(message)