Update npm dependencies

[adbutterfield]

Great package you have here, but I noticed the dependencies are out of date.

I ran the test script, and everything is still green.

[dalemartyn]

you might want to check the 'del' dependancy. it changed to a promise API, so it might break the callback on line 33. Tests will pass as the tests use a different delFn.

[callumacrae]

Hey. Happy to accept this PR (except for the note above), but there's a conflict now.

[adbutterfield]

Ah, I totally forgot about this. One of my goals this year is to start contributing back to open source projects I use.

I fixed just the conflict, and I'll look at the other issue today!

[adbutterfield]

I implemented a change where delFn is always a promise. Not sure if it's a naive fix or not.

Also I noticed the syntax wasn't consistent, so I beautified the code.

[adbutterfield]

I also tried it in a project I'm working on right now, and it's working with no problems.

[callumacrae]

I totally forgot about this too - my bad!

Nice, happy with this except for one thing: not really happy adding bluebird as a dependency just to promisify a function that is only really used during testing.

Two alternatives:

• Manually wrap deleteFn with a native promise and update the version required
• Just turn deleteFn into a promise to match del. It isn't documented, so it's fine to change this

Both are breaking changes, but I'm happy not supporting Node 0.10 anymore.

[adbutterfield]

Yeah, I took the lazy route and just used bluebird.

Is there an easy way to turn a non-promise into a promise with the native Promise? I've actually only used bluebird for that sort of thing.

Or, if you want to change it so that delFn option has to be a promise, I could just remove bluebird. Then delFn in the tests would have to be updated to be promises I guess?

[callumacrae]

function promisify(fn) {
  return new Promise(function (resolve) {
    fn(resolve);
  });
}

Untested, but something like that should work. Could also wrap it in a try-catch block for the reject function, but I don't think that's necessary in this case.

[adbutterfield]

That didn't seem to work.

I did come across this package though, and this solution seems to work:
https://github.com/jcollado/promisify-function/blob/master/src/index.js

Maybe could just add it as a dev dependency?

[callumacrae]

Ah what I wrote isn't a promisify function, it's what you would return as delFn - ignore that!

This should work:

function promisify(fn) {
  return function () {
    var args = Array.prototype.slice.call(arguments);
    return new Promise(function (resolve) {
      fn.apply(null, args.concat(resolve));
    });
  };
}

If that doesn't work just go ahead and add the dependency :)

[adbutterfield]

That one didn't quite do it either. I swapped out bluebird for that promisify-function package.

[adbutterfield]

Oh also, I just realized, that promisify-function package uses babel to transpile for compatibility back to only node 4.

[callumacrae]

Looks good now! I've updated the travis versions on master, could you rebase onto master and then when the tests are merged I'll merge this.

Thanks!

[adbutterfield]

So I did a squash rebase on the branch. The things I did in this PR, in case you want to add it to the release notes:

• Update npm dependencies
• Beautify index.js for consistent syntax
• Change call to del to use promise rather than callback
• Wrapped custom delFn with promise using promisify-function package