stream-with-context.js

const streamWithContext = (context, stream) => ({
  async next(value) {
    return Promise.race([context.cancelled, stream.next(await value)]);
  },
  async return(value) {
    return Promise.race([context.cancelled, stream.return(await value)]);
  },
  async throw(error) {
    return Promise.race([context.cancelled, stream.throw(await error)]);
  },
  [Symbol.asyncIterator]() {
    return this;
  },
});