JavaScript ES6 promise for loop

by 
for (let i = 0; i < 10; i++) {
    const promise = new Promise((resolve, reject) => {
        const timeout = Math.random() * 1000;
        setTimeout(() => {
            console.log(i);
        }, timeout);
    });

    // TODO: Chain this promise to the previous one (maybe without having it running?)
}

The above will give the following random output:

6
9
4
8
5
1
7
2
3
0

The task is simple: Make sure each promise runs only after the other one (.then()).

For some reason, I couldn’t find a way to do it.

I tried generator functions (yield), tried simple functions that return a promise, but at the end of the day it always comes down to the same problem: The loop is synchronous.

With async I’d simply use async.series().

How do you solve it?

7 Answers
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