feat: complete native Windows 11 support

[Ofekw]

Heads-up on scope

The biggest call here is replacing three bash scripts (build-bin, build-npm, install-bin) with TypeScript. The smaller alternatives I considered:

• Keep the bash scripts and document Git Bash as a Windows requirement. This is what already happens implicitly in CI (windows-latest ships Git Bash), but it pushes real friction onto Windows contributors and doesn't fix the bash: not found errors on stock Windows.
• Ship parallel .ps1 and .sh pairs. More files, two ways to drift, and the rest of this directory is already TS.

If you'd rather take a smaller version of this PR, the docs and the small fixes (stage-prebuilt-npm.ts dist/hunk.exe lookup, npm.cmd resolution, PATH case-collision) can land first and the bash → TS port can wait. Happy to split.

---

Builds on #282. With that merged, the release pipeline knows how to publish a Windows binary, but the local build and packaging scripts still assume bash. They fall over before reaching the new code path. After this PR, bun run build:prebuilt:npm, bun run check:prebuilt-pack, and bun run smoke:prebuilt-install all complete on native Windows 11 x64.

Changes

feat(scripts): port build/install bash scripts to TypeScript

• scripts/build-bin.sh → scripts/build-bin.ts. Writes dist/hunk on Unix and dist/hunk.exe on Windows, matching what bun build --compile actually emits.
• scripts/build-npm.sh → scripts/build-npm.ts. Skips chmod 0755 on Windows and replaces the shell glob with readdirSync.
• scripts/install-bin.sh → scripts/install-bin.ts. Defaults to %LOCALAPPDATA%\Programs\hunk on Windows and ~/.local/bin on Unix, still honors HUNK_INSTALL_DIR, and case-folds before checking PATH on Windows.
• package.json invokes bun run ./scripts/*.ts instead of bash ./scripts/*.sh.

fix(scripts): make repo scripts work on native Windows

A new scripts/script-helpers.ts holds two helpers, both threaded through the existing scripts:

• npmCommand resolves to npm.cmd on Windows. Bun.spawn can't exec the Unix-style npm shim that Node ships next to npm.cmd (same applies to Node child_process without shell: true).
• envWithPath(path) strips every case-variant of PATH/Path/etc. before setting PATH. The reason: on Windows, { ...process.env, PATH: sanitized } leaves the original Path key in the object, the child inherits both, and binaries resolve from the un-sanitized union. The smoke test's bun unexpectedly available guard was silently passing the wrong PATH because of this.

Three smaller fixes:

• stage-prebuilt-npm.ts hardcoded dist/hunk for the host-only artifact. Now calls binaryFilenameForSpec(getHostPlatformPackageSpec()).
• smoke-prebuilt-install.ts no longer requires bash on PATH on Windows. The npm-installed hunk.cmd shim doesn't shell out via bash.
• check-pack.ts, check-prebuilt-pack.ts, and publish-prebuilt-npm.ts all use npmCommand.

docs: declare native Windows support

• README requirements: Windows listed alongside macOS and Linux.
• CONTRIBUTING dev-setup: notes that native Windows works without WSL or Git Bash.
• CHANGELOG [Unreleased]: records the port and the docs alongside the existing PR feat(release): publish Windows prebuilt artifacts #282 entry.

Verification (Windows 11 x64, Bun 1.3.11, Node 24.14.0)

Command	Before	After
bun run build:bin	❌ bash: not found	✅ builds dist/hunk.exe
bun run build:npm	❌ bash: not found	✅ builds dist/npm/main.js + opentui types
bun run check:pack	❌ spawn npm ENOENT	✅ Verified npm pack output for hunkdiff@…
bun run build:prebuilt:npm	❌ Missing compiled binary at dist/hunk	✅ stages hunkdiff + hunkdiff-windows-x64
bun run check:prebuilt-pack	❌ spawn npm ENOENT	✅ Verified prebuilt npm packages
bun run smoke:prebuilt-install	❌ bash: not found, or bun unexpectedly available once bash is on PATH	✅ Verified prebuilt npm install smoke test with hunkdiff-windows-x64
bun run install:bin with HUNK_INSTALL_DIR=<tmp>	❌	✅ Installed …\hunk.exe
bun run typecheck and bun run lint	✅	✅

bun run format:check flags the same pre-existing CLAUDE.md issue on main; this PR doesn't touch it.

Out of scope

• Shipping hunkdiff-windows-x64 to npm. That's a tag, not a code change. The release workflow handles it on the next tag.
• The 5 jj test failures locally. They need Jujutsu on the host; CI installs jj-cli via taiki-e/install-action.

[Ofekw]

Just an example screenshot of this PR of hunk running locally on my windows 11 machine:

[greptile-apps]

Greptile Summary

This PR completes native Windows 11 support by porting three bash scripts (build-bin, build-npm, install-bin) to cross-platform TypeScript and fixing a handful of Windows-specific bugs in the existing scripts.

• Bash → TypeScript port: build-bin.ts, build-npm.ts, and install-bin.ts replace their .sh counterparts. Each script handles platform differences explicitly: .exe suffix on Windows, chmod guarded behind a non-Windows check, and a %LOCALAPPDATA%\Programs\hunk default install path.
• script-helpers.ts: Introduces npmCommand (npm.cmd on Windows) and envWithPath, which strips all case-variants of the PATH key before setting it — fixing a subtle Windows env-inheritance bug where { ...process.env, PATH: x } silently inherits the original Path key alongside the new PATH key.
• stage-prebuilt-npm.ts / smoke-prebuilt-install.ts: Fix hardcoded dist/hunk binary lookup and propagate npmCommand/envWithPath throughout.

Confidence Score: 4/5

Safe to merge. All changed paths are build/install scripts; no production runtime code is touched.

The Windows-specific logic is well-reasoned and the envWithPath helper correctly addresses the case-collision problem described in the PR. The two style observations (redundant if (!entry) guard and a second call to getHostPlatformPackageSpec() in the log path) are trivial and carry no correctness risk.

No files require special attention beyond the two minor style nits in scripts/install-bin.ts and scripts/stage-prebuilt-npm.ts.

Important Files Changed

Filename	Overview
scripts/script-helpers.ts	New shared helpers: npmCommand (resolves npm.cmd on Windows) and envWithPath (strips all case-variants of PATH before setting it, avoiding the Windows case-collision bug).
scripts/install-bin.ts	Bash-to-TypeScript port of install-bin. Adds Windows default install dir, case-insensitive PATH check, and omits chmod on Windows. Minor: filter(Boolean) before the .some() callback already removes empty entries, making the if (!entry) return false guard redundant.
scripts/build-bin.ts	Bash-to-TypeScript port. Correctly resolves hunk.exe on Windows vs hunk on Unix and cleans up the legacy otdiff/otdiff.exe binary.
scripts/build-npm.ts	Bash-to-TypeScript port. Replaces shell glob with readdirSync for .d.ts copy and guards chmodSync behind a non-Windows check.
scripts/smoke-prebuilt-install.ts	Updated to use npmCommand, envWithPath, and conditionally omit bash from the sanitized PATH on Windows. commandPath uses where on Windows, bash -lc on Unix.
scripts/stage-prebuilt-npm.ts	Fixed hardcoded dist/hunk lookup to use binaryFilenameForSpec, but the log message at the end re-invokes getHostPlatformPackageSpec() when the IIFE's hostSpec is out of scope.
package.json	Three script entries updated from bash ./scripts/*.sh to bun run ./scripts/*.ts; no other changes.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A["bun run build:bin\nbuild-bin.ts"] --> B{"process.platform"}
    B -- win32 --> C["dist/hunk.exe"]
    B -- unix --> D["dist/hunk"]

    E["bun run build:npm\nbuild-npm.ts"] --> F["dist/npm/main.js"]
    E --> G["dist/npm/opentui/index.js + *.d.ts"]
    F -- "non-Windows only" --> H["chmodSync 0755"]

    I["bun run install:bin\ninstall-bin.ts"] --> A
    I --> J{"HUNK_INSTALL_DIR?"}
    J -- set --> K["custom dir"]
    J -- unset + win32 --> L["%LOCALAPPDATA%\\Programs\\hunk"]
    J -- unset + unix --> M["~/.local/bin"]
    K & L & M --> N["copyFileSync binary to installPath"]
    N --> O["PATH check\ncase-insensitive on win32"]

    P["bun run build:prebuilt:npm\nstage-prebuilt-npm.ts"] --> E
    P --> A
    P --> Q["binaryFilenameForSpec(hostSpec)\ndist/hunk OR dist/hunk.exe"]

    R["smoke-prebuilt-install.ts"] --> S["npmCommand pack/install"]
    S --> T["envWithPath\nstrips PATH case-variants"]
    T --> U["run hunk --help / --version"]

Loading

Prompt To Fix All With AI

Fix the following 2 code review issues. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 2
scripts/install-bin.ts:48-51
The `.filter(Boolean)` on line 48 already removes all falsy entries (including empty strings) from `pathEntries`, so the `if (!entry) return false` guard inside the `.some()` callback is unreachable. The inner check can be dropped.

```suggestion
const pathEntries = (process.env.PATH ?? "").split(path.delimiter).filter(Boolean);
const installDirOnPath = pathEntries.some((entry) => {
  // Windows paths are case-insensitive; normalize both sides for the comparison.
```

### Issue 2 of 2
scripts/stage-prebuilt-npm.ts:174-184
`getHostPlatformPackageSpec()` is called twice in the non-`artifactRoot` path: once inside the IIFE (line 177) and again in the closing log (line 202). The IIFE's `hostSpec` is out of scope by then, so the function is invoked a second time. Hoisting `hostSpec` eliminates the duplicate call and removes the need for the IIFE pattern entirely.

```suggestion
const hostSpec = artifactRoot ? undefined : getHostPlatformPackageSpec();
const artifacts = artifactRoot
  ? collectArtifactSpecs(artifactRoot)
  : [
      {
        spec: hostSpec!,
        compiledBinary: path.join(repoRoot, "dist", binaryFilenameForSpec(hostSpec!)),
      },
    ];
```

_{Reviews (1): Last reviewed commit: "docs: declare native Windows support" | Re-trigger Greptile}