微信小程序wx.request的Promise封装。

const METHOD={
  GET:'GET',
  POST:'POST',
  PUT:'PUT',
  DELETE:'DELETE'
}
class Request{
  _header={
    token:null
  }
  _baseUrl=null

  interceptors = []

  constructor(){
    const token=wx.getStorageSync('token')
    if(token){
      this._header.token=token
    }
  }

  intercept(res){
    return this.interceptors
                  .filter(f=> typeof f === 'function')
                  .every(f=> f(res))
  }

  request({url,method,header={},data}){
    return new Promise((resolve,reject)=>{
      wx.request({
        url: (this._baseUrl || '')+url,
        method: method || METHOD.GET,
        data: data,
        header: {
          ...this._header,
          ...header
        },
        success: res=>this.intercept(res) && resolve(res),
        fail:reject
      })
    })
  }

  get(url,data,header){
    return this.request({url,method:METHOD.GET,header,data})
  }
  post(url,data,header){
    return this.request({url,method:METHOD.POST,header,data})
  }
  put(url,data,header){
    return this.request({url,method:METHOD.PUT,header,data})
  }
  delete(url,data,header){
    return this.request({url,method:METHOD.DELETE,header,data})
  }

  token(token){
    this._header.token=token
    return this
  }
  header(header){
    this._header=header
    return this
  }
  baseUrl(baseUrl){
    this._baseUrl=baseUrl
    return this
  }
  interceptor(f){
    if(typeof f === 'function'){
      this.interceptors.push(f)
    }
    return this
  }
}
export default new Request
export {METHOD}