Feature: Autocomplete prompt

[mokkabonna]

I have created a POC for a autocomplete prompt. See the example for a live example.

Is this something that would be considered for inclusion in this library?

I have tried to use the api as used by other prompts although when introducing async I feel it is a bit weird. Any suggestions on how to do this instead? like the choices:

If you now define a function as your choices (as with other prompts) you have to return a inner function that gets called whenever the users input changes. This works fine, but maybe could be done better, and might be confusing.

Fake search function below (from the example):

choices: function (answers) {
  return function(searchTerm) {
    return new Promise(function(resolve, reject) {
      setTimeout(function() {
        resolve(states.filter(function(state) {
          return new RegExp(searchTerm, 'i').exec(state) !== null;
        }));
      }, 400); // simulate 400 ms delay for async request
    });
  };
}

Since the choices also aren't available at creation of the prompt it won't create a Choices object like normally, so I am creating that each time the search function is returning it's result. Is this necessary? Ideally I would just use a simple array, but there might be good reasons why you want them created as choice objects.

It is also an assumption that the search function returns a promise. I feel that promises are the way to go with async these days. Thoughts?

This PR is not complete, but meant as a proof of concept and as as place to discuss it. I have however already some tests.

I have also added a grunt develop task, just for my own sake really, I'll rebase and remove if not wanted.

The style and formatting of the code might also be a bit off, will gladly comply to whatever style is desired, just wasn't my focus right now.

As suggested here #225 I have based it of the list prompt.

[mokkabonna]

Not sure what to do with default for this prompt, since we have a external unknown at runtime resultset. If you want a default, maybe have the service return that choice if no match? Or should we allow a default choice(s) that is used as resultset if the search returns empty array?

[derhuerst]

Looking forward to see this getting merged. 👍

[lazabogdan]

+1

[SBoudrias]

Hey! Thanks for working on this.

This prompt should be published as it's own npm package. Inquirer allow to be extended with custom prompt type:

inquirer.registerPrompt('search', require('your-module');
inquirer.prompt({ type: 'search', ... });

This would allow you to stay the owner the that module and fixing, patching and releasing new versions of it!

[mokkabonna]

For anyone interested, I have started progress on the prompt here: https://github.com/mokkabonna/inquirer-autocomplete-prompt

Not published as a npm package yet. Feedback is welcome.

[patrick-motard]

Looks like inquirer-autocomplete-prompt is now published on npm.