import stream from 'stream'; // 默认导入整个模块
const { EventEmitter, once } = stream; // 从中解构出 EventEmitter

// 事件
export const emitter = new EventEmitter();
type EmitterType = typeof emitter;
// 异步触发事件 demo
export const asyncEmit = (emitter: EmitterType, eventName: string) => {
  return new Promise((resolve) => {
    emitter.once(eventName, (value: any) => resolve(value));
  });
};

async function main() {
  setTimeout(() => {
    emitter.emit('asyncEvent', '监听器中的值');
  }, 1000);
  asyncEmit(emitter, 'asyncEvent').then((result) => {
    console.log(result); // 监听器中的值
  });
}