Is it possible to override native fetch api to use a desired Promise library instead of native browser Promise?

Question

Here is what I mean.

If the browser natively supports fetch api (for example, Chrome), then it uses the native browser Promise.

If I use another Promise library, (like bluebird, for example), native fetch still isn't using it — it uses native Promise implementation instead.

Is there a way to override that?

Problem example:

window.Promise = function () { return null; };


fetch('/api')
.then(function (res) {
    console.log('fetch result!', res); // still works because it uses native Promise
});

Why would I need that, you may be wondering? I wish to make use global rejection events which bluebird library supports and native Promises don't have.

Answer 1

Here's some code that goes along the same line as @MinusFour suggested. Replace global with window if you're in a browser and not inside a module.

const fetch = global.fetch
global.fetch = function() {
    return Promise.resolve(fetch.apply(global, arguments))
}