Add test for ES6 Promises

[kristerkari]

This feature test is from Jake Archibald's ES6 Promises polyfill.

Quick browser test:
Firefox 26 returns false
Chrome 31.0.1650.63 returns false
Chrome 34.0.1766.0 canary returns true

[patrickkettner]

I don't really dig the repetition of of window.Promise, but thats not a big deal.

could you add the polyfill to @jakearchibald's test that you linked to in the PR link?

Also, I know that @paulirish had spoken with @stucox about adding a promise based syntax to the async tests. Are you guys cool with Modernizr.promises being taken up by a detect? I can't imagine using that for the actual API, but worth making sure

[kristerkari]

could you add the polyfill to @jakearchibald's test that you linked to in the PR link?

Sorry, I did not quite understand this, add what where?

[patrickkettner]

Sorry, upon rereading that that was really unclear.

Could you add the ES6-Promises polyfill that you linked to to the polyfills.json and document it in this feature-detect

[kristerkari]

Alright, sure thing.

[kristerkari]

Ok, PR updated. Added "polyfills" and "caniuse" name.

[patrickkettner]

beautiful work, as always. 👍 from me, @stucox, you good with about the above API question?

[stucox]

Sorry for the delay on weighing in on this. promises is definitely the most obvious name for this detect.

I can’t picture us using Modernizr.promises for a promise-compatible API syntax, but the very similar Modernizr.promise could be a vague possibility.

That said, my current thinking is that we’d just extend Modernizr.on() to make it promise-compliant, e.g.:

Modernizr.on('webp').then(function (result) {
    // WebP supported
}, function (error) {
    // WebP not supported
});

[patrickkettner]

beauty, we were on the same train afterall.