Unhandled promise rejection with TypeError when using async iterator

[acostalima]

Both repros below error out the stream after some time.

In test 1, reader.read() read throws as expected.

In test 2, the output is as follows:

Possible Unhandled Promise Rejection (id: 0):
TypeError: reader._closedPromise_reject is not a function. (In 'reader._closedPromise_reject(reason)', 'reader._closedPromise_reject' is undefined)

If I wrap controller.error() with a try/catch block, the error above is caught and the try/catch block of for..await behaves exactly the same as in test 1.

Is this the intended behavior or am I doing something wrong? 🤔

NOTE: I'm using the polyfill in React Native.

Test case 1

const readableStreamTest1 = async () => {
  const delay = (ms) => new Promise((resolve) => setTimeout(resolve, ms));
  let controller;

  const rs = new ReadableStream({
    async pull(c) {
      controller = c;
      await delay(250);
      c.enqueue('readable');
      await delay(250);
      c.enqueue('stream');
      await delay(250);
      c.enqueue('polyfill');
      c.close();
    },
  });

  const reader = rs.getReader();

  const read = () => {
    return reader
      .read()
      .then(({done, value}) => {
        if (done) {
          console.log('readableStreamTest1 done');
          return;
        }

        console.log('readableStreamTest1 read', {value});

        return read();
      })
      .catch((error) => console.error('readableStreamTest1 read', {error}));
  };

  read();
  await delay(500);
  controller.error(new Error('error'));
};

Test case 2

const readableStreamTest2 = async () => {
  const delay = (ms) => new Promise((resolve) => setTimeout(resolve, ms));
  let controller;

  const rs = new ReadableStream({
    async pull(c) {
      controller = c;
      await delay(250);
      c.enqueue('readable');
      await delay(250);
      c.enqueue('stream');
      await delay(250);
      c.enqueue('polyfill');
      c.close();
    },
  });

  const read = async () => {
    try {
      for await (const chunk of rs) {
        console.log('readableStreamTest2 read', {chunk});
      }
    } catch (error) {
      console.error('readableStreamTest2 read', {error});
    }
  };

  read();
  await delay(500);
  try {
    controller.error(new Error('error'));
  } catch (error) {
    console.error('readableStreamTest2 controller.error', {error});
  }
};

[MattiasBuelens]

Thanks for reporting!

A similar issue was reported yesterday (#66), which is fixed in the latest 3.0.1 release. Could you try updating to that version?

[acostalima]

@MattiasBuelens will do. Sorry for missing that earlier report! 🙏

Thanks!

[acostalima]

@MattiasBuelens I confirm it's fixed now. 💪