dantheman•2y ago

How can I create a linked [ReadableStream,WritableStream] pair?

Hi, I have a function A which accepts a WritableStream and another function B which accepts a ReadableStream. How can I plug them into each other so that the writes from function A will be given to function B? In NodeJS this could be accomplished with an NPM package like https://github.com/indutny/stream-pair.

2 Replies

Andreu Botella (they/them)•2y ago

const identityTransform = new TransformStream();
a(identityTransform.writable);
b(identityTransform.readable);

const identityTransform = new TransformStream();
a(identityTransform.writable);
b(identityTransform.readable);

danthemanOP•2y ago

hah, that's brilliant ok works great for duplex too

function makeSocketPair() {
  const sideA = new TransformStream<Uint8Array>();
  const sideB = new TransformStream<Uint8Array>();
  return {
    left:  { readable: sideA.readable, writable: sideB.writable },
    right: { readable: sideB.readable, writable: sideA.writable },
  };
}

function makeSocketPair() {
  const sideA = new TransformStream<Uint8Array>();
  const sideB = new TransformStream<Uint8Array>();
  return {
    left:  { readable: sideA.readable, writable: sideB.writable },
    right: { readable: sideB.readable, writable: sideA.writable },
  };
}

thank you!