stream: expose ReadableStreamTee

[mcollina]

Refs: nodejs/undici#5358

Expose ReadableStreamTee() so Fetch body clone can use cloneForBranch2.

[nodejs-github-bot]

Review requested:

• @nodejs/streams

[MattiasBuelens]

I don't know if we should be exposing this as a top-level function. At the very least, we should mark ReadableStreamTee() as experimental and guide users towards readableStream.tee() for "common" use cases.

Ideally, we land on a solution in the Streams standard itself. The current proposal is to add an options bag to tee(), so you could write readableStream.tee({ clone: true }). Tracking issue: whatwg/streams#1156.

[KhafraDev]

Ideally, we land on a solution in the Streams standard itself. The current proposal is to add an options bag to tee(), so you could write readableStream.tee({ clone: true }). Tracking issue: whatwg/streams#1156.

This would be great, but it doesn't look like browsers have any interest in implementing it, considering the issue is nearly 5 years old.

[mcollina]

@KhafraDev @MattiasBuelens should we expose this verbatim or change the name to webStreams.tee(stream, opts)

[KhafraDev]

ReadableStreamTee might be a little verbose. Honestly the only reason I didn't try implementing this myself was because I don't particularly like the verbose name, but didn't have any better ideas