Does await await promise-like objects?

Question

According to Mozilla, await only awaits Promises:

[rv] Returns the resolved value of the promise, or the value itself if it's not a Promise.

If you await a non-Promise, a resolved promise will be immediately returned, and it will not await. However, the following code awaits without using Promises in Chrome & FF.

var obj = {
    then:func => obj.func=func
};
setTimeout(() => obj.func(57), 1000);

async function go() {
    var res = await obj;
    console.log(res); //shows '57' after 1000ms
}

go();

According to the specs, should await await promise-like objects that are not Promises? (I tried looking at the specs (linked from the Mozilla article), but I couldn't understand it.)

Does await await promise-like objects?

2 Answers