Parse request for then callback

[JosephSilber]

Currently, the callback is called with 3 parameters: callback(result, status, xhr). This is supplied by the parseReq function.

However, this is only done for the success, error & always methods (and by extension, the callback passed to the initial call). The actual promise returned still resolves to just the raw xhr object.

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I think it would make more sense to pipe the promise directly into parseReq:

promise = promise.then(parseReq, function(request) {
    var promise = new Promise(function(resolve, reject) {
         reject.apply(promise, parseReq(request));
    }));

    return promise;
});

Then the aliases become just that: aliases.

var aliases = Object.create(null, {
    'success' : 'then',
    'error'   : 'catch',
    'always'  : 'finally',
});

for (var alias in aliases) {
    promise[alias] = promise[aliases[alias]].bind(promise);
}

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The only issue here is that sadly most current promise implementations do not support multi-value fulfillment. We can either pass an array to then, or just pass the parsed result.

[JosephSilber]

Actually, after giving this more thought, I don't think it really makes any sense to fulfill with an array.

So instead, here's what I propose:

We keep the current callbacks as is, but we only pass the result to then. I think it makes way more sense than passing it the xhr directly. 99% of the time the result is really all you want.

[JosephSilber]

On further thought¹, if we'll implement request/response interceptors (à la angular), we'll probably want the actual xhr object in there.

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¹ sorry if I'm spamming someone's inbox here...

[JosephSilber]

Closing in favor of #18