`TODO: stream.Readable stdio` and `TODO: stream.Writable stdio` (`node` compat)

[lgarron]

What is the problem this feature would solve?

Passing a Readable (more generally a Readable) to the stdin of a node subprocess is useful, but it hits this TODO in bun:

bun/src/js/node/child_process.ts

Lines 1607 to 1616 in a5712b9

	if (isNodeStreamReadable(item)) {
	if (Object.hasOwn(item, "fd") && typeof item.fd === "number") return item.fd;
	if (item._handle && typeof item._handle.fd === "number") return item._handle.fd;
	throw new Error(`TODO: stream.Readable stdio @ ${index}`);
	}
	if (isNodeStreamWritable(item)) {
	if (Object.hasOwn(item, "fd") && typeof item.fd === "number") return item.fd;
	if (item._handle && typeof item._handle.fd === "number") return item._handle.fd;
	throw new Error(`TODO: stream.Writable stdio @ ${index}`);
	}

It would be nice to be able to use this feature to write portable code.

What is the feature you are proposing to solve the problem?

Implement the TODO.

What alternatives have you considered?

Hack in some workarounds, I guess?

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🔗 Related PRs

#22322 - Fix child_process stdio properties not enumerable for Object.assign() compatibility [merged]
#22591 - Fix TTY reopening after stdin EOF [merged]
#23362 - Fix process.stdin not receiving data after pause/resume [merged]
#23772 - WIP: fix windows ENOTCONN [merged]
#24372 - docs(bun-types): Replace depricated readableStreamToText in type docu… [merged]

👤 Suggested Assignees

• robobun
• dylan-conway
• nkxxll

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[github-actions]

Found 2 possible duplicate issues:

1. Invalid stdio option: "[object ReadStream]" #7959
2. spawn in Bun Fails to Properly Handle FFmpeg Custom Pipes (e.g., pipe:3) #17989

This issue will be automatically closed as a duplicate in 3 days.

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