fix: gate cmd switch escaping to MSYS

[zkochan]

Summary:

• preserve POSIX basedir in sh shims while keeping a Windows basedir for native executables
• use //C for cmd shims only under MSYS-like shells, and keep /C for WSL and other shells

Tests:

• pnpm test

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Written by an agent (Codex, GPT-5).

Summary by CodeRabbit

• Bug Fixes

  • Improved Windows environment detection and command-line argument handling for MSYS/Cygwin compatibility.
  • Enhanced path conversion logic in shell scripts for better Windows and POSIX environment handling.

• Refactor

  • Optimized shell script generation structure for clearer environment-specific behavior separation.

[coderabbitai]

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: ba997eb9-a348-4f1e-9d06-58f306ee4128

📥 Commits

Reviewing files that changed from the base of the PR and between 001f86b and 4a16c7c.

📒 Files selected for processing (3)

• src/index.ts
• test/e2e.test.js.snapshot
• test/test.js.snapshot

📝 Walkthrough

Walkthrough

Refactors generateShShim in src/index.ts to track basedir_win and an msys flag separately from basedir, introduces isCmdRuntime detection, adds a generateExecBlock helper, and conditionally wraps cmd-runtime exec dispatch in an MSYS branch that applies escapeMsysCmdSwitches. All affected shell shim snapshots are updated accordingly.

Changes

MSYS-aware sh shim generation

Layer / File(s)	Summary
New generator variables: shTarget_win and isCmdRuntime src/index.ts	Adds shTarget_win for the Windows-form target path and isCmdRuntime boolean to identify cmd/cmd.exe runtime shims inside generateShShim.
Generated shell: msys flag and uname -a branch rewrite src/index.ts	Rewrites the generated shell script's MSYS/CYGWIN/MINGW detection block to initialize msys, assign basedir_win via cygpath (instead of rewriting basedir), and set msys="true".
Generated shell: conditional MSYS exec dispatch and indentShellBlock src/index.ts	Introduces generateExecBlock helper and wraps cmd-runtime shims in if [ -n "$msys" ] to apply escapeMsysCmdSwitches on MSYS; adds indentShellBlock to format nested shell blocks.
Snapshot updates for all sh shim variants test/test.js.snapshot	Updates bat.shim, all env.shim variants, sh.shim variants, exe.shim variants, env.args.shim, and from.env.s.shim to reflect the new msys initialization, basedir_win via cygpath, and (for bat.shim) the //C vs /C conditional dispatch.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• pnpm/cmd-shim#55: Directly overlaps with this PR's escapeMsysCmdSwitches integration and MSYS-conditional exec logic inside generateShShim.
• pnpm/cmd-shim#56: Modifies generateShShim to introduce basedir_win and Windows-target path variables through uname -a platform detection, the same mechanism refactored here.
• pnpm/cmd-shim#53: Changes generateShShim exec/dispatch semantics in the generated sh binstubs, which is the same code area reorganized in this PR.

Poem

🐇 Hop, hop through the Cygwin path,
basedir_win now avoids the wrath!
msys flag raised, the switch goes //C,
No more mangled args — we're finally free.
With indented blocks all neat and trim,
This bunny ships shims on every whim! 🥕

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'fix: gate cmd switch escaping to MSYS' directly describes the main objective: conditional cmd switch escaping based on MSYS environment.
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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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix-qodo-msys-wsl-cmd-shim

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[qodo-free-for-open-source-projects]

PR Summary by Qodo

Gate cmd /C switch escaping to MSYS shells in sh shims
🐞 Bug fix 🧪 Tests 🕐 20-40 Minutes

Walkthroughs

Description

• Preserve POSIX basedir while maintaining a Windows basedir for native executables.
• Only apply MSYS //C escaping for cmd shims under MSYS/Cygwin/Mingw shells.
• Update shim snapshot expectations for the new MSYS-gated execution logic.

Diagram

graph TD
  A["generateShShim()"] --> B{"uname indicates MSYS?"}
  B -->|"yes"| C["set basedir_win via cygpath + msys=true"] --> D{"cmd runtime?"}
  B -->|"no"| E["keep basedir (POSIX) + basedir_win"] --> D
  D -->|"yes"| F["exec with escaped switches (//C)"]
  D -->|"no"| G["exec with original args (/C etc.)"]

Loading

High-Level Assessment

The following are alternative approaches to this PR:

1. Detect MSYS via environment variables (e.g., MSYSTEM) instead of uname

• ➕ Potentially faster and less error-prone than parsing uname output
• ➕ Avoids edge cases where uname strings differ across distributions
• ➖ Not all MSYS-like environments reliably export the same variables
• ➖ May reduce portability compared to uname-based detection already used

2. Always use //C for cmd shims on any non-Windows sh shell

• ➕ Simplifies logic (no runtime MSYS gating)
• ➕ Eliminates MSYS path-translation failure mode unconditionally
• ➖ Risk of breaking WSL/other shells where /C is expected/standard
• ➖ Harder to reason about correctness outside MSYS-specific behavior

Recommendation: Keep the PR’s runtime MSYS gating approach: it addresses the MSYS argument translation bug while preserving expected behavior on WSL and other shells. uname-based detection is consistent with existing shim platform branching and avoids relying on environment-variable conventions.

File Changes

Bug fix (1)

index.ts Gate MSYS cmd switch escaping and preserve POSIX basedir in sh shims +42/-30

Gate MSYS cmd switch escaping and preserve POSIX basedir in sh shims

• Refactors sh shim exec generation to compute cmd-runtime status once and to assemble execution blocks via a helper. Introduces an 'msys' runtime flag in the emitted shell script, preserves POSIX 'basedir' while computing 'basedir_win' via 'cygpath', and conditionally applies 'escapeMsysCmdSwitches()' only when running under MSYS-like shells.

src/index.ts

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Tests (1)

test.js.snapshot Update snapshots for MSYS-gated cmd shim execution +70/-39

Update snapshots for MSYS-gated cmd shim execution

• Updates expected shim output to include the new 'msys' variable initialization and the conditional exec blocks that use '//C' only under MSYS and '/C' otherwise.

test/test.js.snapshot

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