Best practice for exposing promisifyable methods

[dignifiedquire]

I have a question on what's the best way for me to write an API that is compatible with promisifyAll.
At the moment it is written in this style

function API () {
  this.do = function (arg1, cb) {
    // do things
    cb(null, res)
  }
  this.nested.do = function (arg2, cb) {
    // do things
   cb(null, res)
  }
}

// usage
var api = new API()
api.do('hello', function (err, res) {...})
api.nested.do('world', function (err, res) {...})

Now this does not work with promisifyAll and I understand why (not using prototype, nested objects). But even if I change it to use API.prototype to assign the methods I still can't get the api.nested.do to be promisifed. Any ideas on how to solve this?

[petkaantonov]

You need to call promisifyAll on the nested object too. Also this issue tracker is only for bug reports or feature requests, questions about usage should be in stack overflow or the mailing list.