There is an edge case worth noting when using the `events.once()` function

to await multiple events emitted on in the same batch of `process.nextTick()`

operations, or whenever multiple events are emitted synchronously. Specifically,

because the `process.nextTick()` queue is drained before the `Promise` microtask

queue, and because `EventEmitter` emits all events synchronously, it is possible

for `events.once()` to miss an event.

const { EventEmitter, once } = require('events');

const myEE = new EventEmitter();

async function foo() {

await once(myEE, 'bar');

console.log('bar');

// This Promise will never resolve because the 'foo' event will

// have already been emitted before the Promise is created.

await once(myEE, 'foo');

console.log('foo');

}

process.nextTick(() => {

myEE.emit('bar');

myEE.emit('foo');

});

foo().then(() => console.log('done'));

To catch both events, create each of the Promises *before* awaiting either

of them, then it becomes possible to use `Promise.all()`, `Promise.race()`,

or `Promise.allSettled()`:

const { EventEmitter, once } = require('events');

const myEE = new EventEmitter();

async function foo() {

await Promise.all([once(myEE, 'bar'), once(myEE, 'foo')]);

console.log('foo', 'bar');

}

process.nextTick(() => {

myEE.emit('bar');

myEE.emit('foo');

});

foo().then(() => console.log('done'));