JavaScript promises, mastering the asynchronous

You are now towards the end of this playground. However, the wild outside can be dangerous. So don't leave without a few tricks!

Test if an object is a promise

If you really have to, this is how you can test if an object is a promise : obj instanceof Promise. The problem is that this test only works with a real Promise object. It will not work with the Q library or with an Angular promise.

Promise.race

Promise.race takes an array of promises. The result is a new promise that resolves or rejects as soon as one of the promises in the given array resolves or rejects.