Add support for the "question" method

[machineghost]

This library is great, except it seems to have left out a key part of the readline API out: the question method.

Currently if I log the method in readline-promise I see:

function (query, cb) {
  if (typeof cb === 'function') {
    if (this._questionCallback) {
      this.prompt();
    } else {
      this._oldPrompt = this._prompt;
      this.setPrompt(query);
      this._questionCallback = cb;
      this.prompt();
    }
  }
} 

In other words, I see the normal (readline not readline-promise) style question function which takes a callback. It would seem more appropriate for the readline-promise version to be something like:

function (query) {
  if (this._questionCallback) {
    return this.prompt();
  } else {
    this._oldPrompt = this._prompt;
    this.setPrompt(query);
    return this.prompt();
  }
} 

(The above assumes prompt returns a promise; if not some further adjustment might be necessary.)

Is something like this possible/desired?

[bhoriuchi]

In general, methods with callbacks are easy to promisify whereas streams take a bit more work. I can add a questionAsync method that would just be something like

function questionAsync(query) {
  return new Promise(resolve => {
    rl.question(query, resolve)
  })
}

[machineghost]

That would be great.

[bhoriuchi]

v1.0.3 has been published with the questionAsync method