setTimeouts are not dispatched in separate tasks

[aslushnikov]

The following reproduces for me on both node 8 and node 10.

let resolve;
const promise = new Promise(x => resolve = x);
promise.then(() => console.log('task1: promise resolved'));

setTimeout(() => {
  console.log('task1: settimeout');
  resolve();
}, 0);
setTimeout(() => console.log('task2: settimeout'), 0);

In Web, every setTimeout will be dispatched in a separate task; as a result, the script will always
yield:

task1: settimeout
task1: promise resolved
task2: settimeout

In node, however, the behavior is flaky and every other time I see the following:

task1: settimeout
task2: settimeout
task1: promise resolved

If this is intended behavior, I didn't find any description in documentation.

This, however, is very unexpected for someone coming from Web to Node.js.

[mscdex]

I believe this is a duplicate of #22257

[aslushnikov]

Awesome. Thanks!