/ignore – Project-Aware .gitignore

Intent

This skill helps the agent create or update a .gitignore file based on the actual project layout and tech stack, instead of using a one-size-fits-all template.

Use it when:

• The user types /ignore
• The user asks to create, update, or audit a .gitignore
• A new project is initialized and no .gitignore exists yet

High-Level Workflow

1. Discover project type and tools
2. Decide which ignore templates apply
3. Generate a .gitignore candidate
4. Safely merge with any existing .gitignore
5. Show a short summary of what was added/changed

Keep changes minimal and reversible (back up existing .gitignore before modifying).

Step 1 – Discover Project Stack

Work from the repository root.

1. Detect languages / frameworks (examples, not exhaustive):
   • Node/JS/TS: package.json, pnpm-lock.yaml, yarn.lock, node_modules/
   • Python: pyproject.toml, requirements.txt, .venv/, __pycache__/
   • Go: go.mod, go.sum
   • Rust: Cargo.toml, Cargo.lock, target/
   • Java / JVM: pom.xml, build.gradle, .gradle/, *.iml
   • Frontend frameworks: next.config.*, vite.config.*, webpack.config.*
2. Detect tools / editors:
   • VS Code: .vscode/
   • JetBrains: .idea/
   • OS junk: .DS_Store, Thumbs.db
3. Detect build / artifact directories:
   • dist/, build/, .turbo/, .next/, coverage/, out/, tmp/, logs/

You do not need to be perfect; detect the obvious signals and choose sensible defaults.

Step 2 – Choose Ignore Coverage

Based on discovery, decide which groups to include:

• Core OS / editor noise: macOS, Windows, IDEs
• Language / runtime specific: Node, Python, Go, Rust, etc.
• Tooling / build artifacts: bundlers, coverage, temporary directories

Prefer including too little over too much:

• Do not ignore lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, Cargo.lock, etc.).
• Do not ignore source directories (src/, app/, etc.).
• Only ignore env/.env.* if consistent with workspace conventions and security rules; never remove existing entries that intentionally ignore env files.

Step 3 – Generate .gitignore Content

Create an in-memory list of lines for the candidate .gitignore with small, focused sections.

Suggested structure (keep each section short):

# OS
.DS_Store
Thumbs.db

# Editors
.vscode/
.idea/

# Node
node_modules/
npm-debug.log*
yarn-debug.log*
yarn-error.log*
pnpm-debug.log*

# Build output
dist/
build/
coverage/
.next/
.turbo/
out/

# Environments
.env.local
.env.development.local
.env.test.local
.env.production.local

Add or remove sections depending on the detected stack (for non-Node projects, skip Node‑specific lines, etc.).

Step 4 – Merge with Existing .gitignore

When a .gitignore already exists:

1. Read existing contents into a set of lines.
2. Back up the file to .gitignore.bak in the repository root before modifying.
3. For each candidate line:
   • If the line is already present (exact string match, ignoring trailing whitespace), do nothing.
   • If it is new, append it at the end in the appropriate section, preserving section comments as much as possible.
4. Avoid deleting or rewriting user-defined patterns; never remove custom rules unless explicitly asked.

When no .gitignore exists:

1. Create a new .gitignore in the project root.
2. Write only the lines relevant to the detected stack and tools.

Step 5 – Report Back to the User

After writing the file, summarize:

• Created vs updated: whether .gitignore was new or modified.
• Key sections added: e.g., “Node artifacts”, “macOS junk files”, “VS Code project settings”.
• Number of new patterns added.

Example summary:

Result: Updated existing .gitignore (backed up to .gitignore.bak).
Added: Node build artifacts, macOS .DS_Store, VS Code workspace folder ignores.
Patterns added: 14 new entries.

Notes & Safety

• Be conservative when inferring what to ignore; it is better to under‑ignore and let the user add more entries than to hide important files.
• Never ignore the entire project directory, .* generically, or critical configuration directories unless the repository already does so.
• If the user asks to regenerate from scratch, confirm by backing up the existing .gitignore and clearly stating that you are replacing its contents.