typescript-playground-example.ts

(<any>Symbol).asyncIterator = Symbol.asyncIterator || Symbol.for("Symbol.asyncIterator");
const sleep = async (ms: number) => new Promise((resolve, reject) => setTimeout(() => resolve(), ms));

class TestClass {
  private awaitable = Promise.resolve([1, 2, 3, 4, 5]);
  
  async *count(count: number): AsyncIterableIterator<number> {
    for (let i = 0; i < count; i++) {
      yield* (async function* () {
        await sleep(100);
        yield i;
      })();
    }
  }

  async log() {
    for await (const item of this.count(100)) {
      console.log(item);
    }
  }
}

const instance = new TestClass();
instance.log();