我的mutation.js

//失败的方法
import * as types from './mutation-types'

const mutations = {
  [types.SET_MUSICLIST](state, payload) {
    state.musicList = payload
  }
}

export default mutations


//成功的方法
// export const SET_MUSICLIST = (state, payload) => {
//   state.musicList = payload
// }

//mutation-types.js
export const SET_MUSICLIST = 'SET_MUSICLIST'

//组件中
...mapMutations({
    SetMusicList: 'SET_MUSICLIST'
})

为什么两种写法会一个成功一个失败呢？是我export不对吗？