returnPromise

simple to the callbackify functions to promisify:

Install

$ npm install --save return-promise

Usage

fs = require('fs')
fs.readFile('/etc/hosts', 'utf8', function (err,data) {
  if (err) {
    return console.log(err);
  }
  console.log(data);
});

=>

require('return-promise');

fs = require('fs');
fs.readFile
  .returnPromise('/etc/hosts', 'utf8')
    .then(data => console.log(data))
    .catch(err => console.log(err));

if you need use this.xxx in the fun:

        const user = {
            name: 'zs',
            sayHi: function (something, cb) {
                cb(null, `Hi, ${something}, i'm ${this.name},`);
            }
        };

        user.sayHi('world', console.log.bind(console));

        it('should can transport this', function () {
            user.sayHi.bind(user) // *** bind to this ***
                .returnPromise('world')
                .then(console.log.bind(console))
                .catch(console.error.bind(console));
        });