JS, what's under the hood of the async await construct?

Question

JavaScript

Hello, what happens when we call await function fetchUser().
I believe that this is a wrapper over a generator that suspends the course of an asynchronous function.
But I've also seen that it's just a call to Promise.all([]). So what's going on under the hood?

Answer 1

Yes, under the hood there are generators and promises. One way to test this is to transpile your async/await code to ES5 using Babel and see what happens. I made a small gist with a test project, you can see the result there. Babel uses regenerator to implement generators.

Answer 2

Detailed answer to the question in English.
async / await is syntactic sugar. Under the hood is a generator and yield .

Answer 3

AsyncFunction source code in V8
Uses generators.