Wrap WeChat Mini Program APIs with a Promise

wxp.js

const methods = [
  'getStorage',
  'setStorage',
  'getSystemInfo'
]
const wxp = {}
methods.forEach((method) => {
  wxp[method] = (args = {}) =>
    new Promise((resolve, reject) => {
      args.success = (res) => resolve(res)
      args.fail = (err) => reject(err)
      wx[method](args)
    })
})

module.exports = wxp