SyntaxError: Could not find export 'ReadableStream' in module 'stream'

[guest271314]

For disambiguity, what I'm referring to herein is WHATWG ReadableStream https://streams.spec.whatwg.org/#rs-class, not Node.js-specific Readable

When you do this

console.log(ReadableStream);

this is printed

[class: ReadableStream]

However, when trying to construct a ReadableStream

let z = 0;
const readable = new globalThis.ReadableStream({
  pull(c) {
    if (z === 5) {
      c.close();
    }
    c.enqueue(new Uint8Array([z]));
    ++z;
  }
});

this error is thrown

[class: ReadableStream]
Error: ReadableStream is not supported via global scope. Enable this by adding this to your code:
	import { ReadableStream } from "stream";
	globalThis.ReadableStream = ReadableStream;

Node.js Readable is not the same as WHATWG ReadableStream, and is not exported by "node:stream"

import * as streams from "node:stream";
console.log(streams);

{
  Duplex: [function: Duplex],
  PassThrough: [function: PassThrough],
  Readable: [function: Readable],
  Stream: [function: Stream],
  Transform: [function: Transform],
  Writable: [function: Writable],
  default: [function: Stream],
  finished: [function: finished],
  pipeline: [function: pipeline]
}

Duplex.toWeb() does convert a Node.js-specific Readable to a WHATWG ReadableStream. We shouldn't need to do that if WHATWG ReadableStream is defined globally.

This needs clarifying.

[Sytten]

Streams is very much a WIP, the ReadableStream currently present is kinda of hack that only works for places where it is used in rust.

[guest271314]

If the real WHATWG ReadableStream is not implemented it probably shouldn't be exposed, especially if the class is exposed, yet the runtime claims it's not a global. Doesn't make sense, to me.

[richarddavison]

@guest271314 WHATWG webstreams are no implementeed (partially). They are however not integrated in fetch for instance.