obs-async-iterator.js

async function consume2(obs) {
  const ai = obs[Symbol.asyncIterator]();
  ai.next().then(r => console.log(0, r), e => console.log(0, e.message));
  ai.next().then(r => console.log(1, r), e => console.log(1, e.message));
  ai.next().then(r => console.log(2, r), e => console.log(2, e.message));
  ai.next().then(r => console.log(3, r), e => console.log(3, e.message));
}
consume2(Observable.interval(100).do(n => console.assert(n < 1)));