编辑代码

class message{
    constructor(){
        this.messages = {};
    }
    on(eventName,func){
      if(!this.messages[eventName]){
          this.messages[eventName] = [func];
      }else{
          this.messages[eventName].push(func);
      }
    }
    emit(eventName){
     this.messages[eventName] && this.messages[eventName].forEach(fun=>fun());
    }
}
let me = new message();

function test(){
    console.log('test测试pass')
}
function test2(){
    console.log('test2测试pass')
}

me.on('test',test);
me.on('test2',test2);

me.emit('test');