async generator function: count until 5

index.js

// works in current chrome (logs from 1 to 5 every second)

function sleep(milliseconds) {
  return new Promise(resolve => setTimeout(resolve, milliseconds))
}

async function* seconds() {
  let second = 0;
  while (true) {
    await sleep(1000);
    second += 1;
    yield second;
  }
}

async function example() {
  for await (const second of seconds()) {
    console.log(second);
    if (second === 5) break;
  }
}

example();