Emitter.js

const Emitter = () => {
  let store = []
  let subscribe = ( name, fn ) => {
    store.push({name, fn})
    return () => {
      store = store.find( el => el.name != name);
    }
  }
  let publish = ( name, data) => store.forEach( obj =>{
    if(obj.name == name) obj.fn( data )  
  })
  return {subscribe, publish}
}

var a = Emitter();

let delBla = a.subscribe('bla', (d) => {
  console.log(d)
})

setTimeout(()=>{
  a.publish('bla', '+100500')
},5 * 1000)

setTimeout(()=>{
  delBla()
},4 * 1000)

setTimeout(()=>{
  a.publish('bla', '-200300')
},3 * 1000)