lint

<working_directory_awareness> Before running any git or build command: check whether your dispatch context specifies a working directory (look for "Working directory:" in your initial prompt). If it does and pwd does not match it, prefix every git invocation with -C <that path> (e.g. git -C /path/to/worktree diff --name-only) and run linters/formatters with the explicit path argument. Linting the wrong directory is a silent failure mode. </working_directory_awareness>

• No arguments: Lint only files changed in the current working tree (git diff --name-only and git diff --cached --name-only).
• A file or directory path: Lint only that specific path (e.g., /lint src/utils).
• --fix: Automatically apply safe fixes. Can be combined with a path (e.g., /lint src/ --fix).
• --fix without a path: Auto-fix changed files only.

Parse the arguments before proceeding. If --fix is present, set fix mode. If a non-flag argument is present, treat it as the target path.

JavaScript/TypeScript Linters:

1. Biome — Look for biome.json or biome.jsonc in the project root.

   • Lint command: npx @biomejs/biome check . (or --apply with --fix)
   • Format command: npx @biomejs/biome format . (or --write with --fix)
   • Biome handles both linting and formatting. No need for a separate formatter if Biome is detected.

2. ESLint — Look for .eslintrc, .eslintrc.* (js, cjs, json, yml, yaml), eslint.config.* (js, mjs, cjs, ts, mts, cts), or an "eslintConfig" key in package.json.

   • Lint command: npx eslint . (or --fix with --fix)
   • Check package.json for the installed version. ESLint 9+ uses flat config (eslint.config.*).

JavaScript/TypeScript Formatters (only if Biome was NOT detected):

1. Prettier — Look for .prettierrc, .prettierrc.*, prettier.config.*, or a "prettier" key in package.json.
   • Format check: npx prettier --check .
   • Format fix: npx prettier --write .

Rust:

1. rustfmt — Look for rustfmt.toml or .rustfmt.toml, or Cargo.toml in the project root.
   • Format check: cargo fmt -- --check
   • Format fix: cargo fmt
   • Lint: cargo clippy (if available)

Go:

1. Go tools — Look for go.mod in the project root.
   • Format check: gofmt -l .
   • Format fix: gofmt -w .
   • Lint: golangci-lint run (if installed), otherwise go vet ./...

Python:

1. Ruff — Look for ruff.toml or a [tool.ruff] section in pyproject.toml.

   • Lint command: ruff check . (or --fix with --fix)
   • Format command: ruff format . (or --check without --fix)

2. Black — Look for a [tool.black] section in pyproject.toml, or black in requirements files.

   • Format check: black --check .
   • Format fix: black .

If no linter or formatter is detected, inform the user and suggest common options for their project type based on the files present.

Step 1: Determine target files

• If a path argument was provided, use that path.
• If no path argument, get changed files:

  git diff --name-only
  git diff --cached --name-only
  

  Filter to files that still exist on disk. If no files are changed, inform the user and offer to lint the entire project instead.

Step 2: Run the detected tools

Run the linter and/or formatter against the target files or directory.

• Without --fix: Run in check/report mode only. Do NOT modify any files.
• With --fix: Run with auto-fix flags enabled.