Fix setRawMode on Windows for non-stdin TTYs

[edemaine]

What does this PR do?

Fixes Windows tty.ReadStream#setRawMode() for reopened console input handles such as \\\\.\\CONIN$.

When stdin is a pipe, tools such as hunk should be able to reopen CONIN$ to recover interactive keyboard input. On Bun, creating new tty.ReadStream(fd) for that reopened console fd reported isTTY === true, but setRawMode(true) failed because the stream did not have a native TTY wrapper. This PR creates a Windows TTYWrap for non-stdin TTY read streams and routes raw-mode changes through it, while preserving Bun’s existing stdin path.

It also adds a Windows regression test covering fs.openSync("\\\\.\\CONIN$", "r+"), new tty.ReadStream(fd), and toggling raw mode on/off. The analogous test works in Node; see nodejs/node#63856

How did you verify your code works?

• Built Bun locally on Windows:

  .\build\debug\bun-debug.exe --version

• Ran the focused tty test:

  .\build\debug\bun-debug.exe test test/js/node/tty.test.ts

• Verified the original pipe/interactive scenario using Hunk:

  git diff | C:\Users\edemaine\Projects\bun\build\debug\bun-debug.exe run ..\hunk\src\main.tsx -- patch -

• Checked patch whitespace:

  git diff --check

I had issues running the full test suite, but I think those errors were unrelated.

[claude]

Claude Code Review

This pull request is from a fork — automated review is disabled. A repository maintainer can comment @claude review to run a one-time review.

[coderabbitai]

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📥 Commits

Reviewing files that changed from the base of the PR and between bcad9b2 and feacc0f.

📒 Files selected for processing (2)

• src/js/node/tty.ts
• test/js/node/tty.test.ts

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Walkthrough

Windows TTY support for reopened CONIN$ streams is enhanced. The module conditionally loads the native TTY binding on Windows, ReadStream constructor allocates a native wrapper for non-stdin TTY fds, setRawMode coordinates with the binding using numeric mode values, and a test verifies raw mode state transitions on reopened CONIN$ streams.

Changes

Windows TTY raw mode support

Layer / File(s)	Summary
Windows TTY binding initialization src/js/node/tty.ts	The module retrieves TTY from process.binding("tty_wrap") on Windows (undefined otherwise), establishing a conditional native binding for subsequent operations.
Windows ReadStream TTY wrapper allocation src/js/node/tty.ts	ReadStream constructor now allocates and stores a native TTY wrapper in this.$bunNativePtr for Windows instances with non-stdin fds that are actual TTYs, enabling raw mode support.
Windows setRawMode native coordination src/js/node/tty.ts	setRawMode ensures the native-readable stream is constructed via optional chaining and passes numeric uv_tty_mode_t values to the TTYWrap binding when the handle is a TTY, otherwise forwards the boolean flag.
Test for raw mode on reopened CONIN$ streams test/js/node/tty.test.ts	New Windows-only test spawns a child process that opens \\.\CONIN$, wraps it in ReadStream, and validates that setRawMode correctly transitions isRaw state from false to true to false.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately and concisely describes the main change: fixing setRawMode on Windows for non-stdin TTY streams.
Description check	✅ Passed	The description includes both required sections with sufficient detail: explains what the PR does (fixes Windows setRawMode for reopened console handles) and how it was verified (local build testing, regression test, and integration testing with hunk).
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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[robobun]

Cross-referencing #34788, which addresses the same setRawMode failed because it was called on something that is not a TTY failure for a tty.ReadStream on a reopened CONIN$ handle. That PR routes every Windows console-input fd (stdin and reopened CONIN$) through a single uv_tty_set_mode path so both end up with UV_TTY_MODE_RAW_VT, and is green on Windows CI. Linking so the two can be considered together and this contribution credited.