async-collect/src/collect.js

Keep asynchronously getting chunks of data as long as a specified condition is met.

export default ({ getChunk, getNextCallsArgs, reduce }) => {
  return collect;

  async function collect(...args) {
    const chunk = await getChunk(...args);
    const nextCallsArgs = getNextCallsArgs(args, chunk);
    if (nextCallsArgs.length === 0) return chunk;
    const nextChunks = [
      chunk,
      ...(await Promise.all(
        nextCallsArgs.map(callArgs => collect(...callArgs))
      ))
    ];
    return reduce(nextChunks);
  }
};