Flattening nested iterators ... for use with weird DynamoDB scan API

iterate.js

const testItems = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
const limit = 2;

const getBatch = (cursor = null) => {
  const currentCursor = cursor || 0;
  const nextPotentialCursor = currentCursor + limit;
  const nextCursor = nextPotentialCursor > 10 ? null : nextPotentialCursor;

  return new Promise(resolve =>
    setTimeout(() => resolve({
      items: testItems.slice(currentCursor, nextCursor),
      cursor: nextCursor
    }), 5000)
  );
};

const getAll = async function* (cursor = null) {
  const { cursor: nextCursor, items } = await getBatch(cursor);

  yield* items;

  if (nextCursor !== null) {
    yield* getAll(nextCursor);
  }
};

const main = async () => {
  for await (const item of getAll()) {
    console.log(item);
  }
}

main();

/*
~ » node iterate.js
1
2
3
4
5
6
7
8
9
10
*/