Code Linting

Run all appropriate linters according to repository guidelines.

When to Use This Skill

Use this skill:

Immediately after creating new source code files
Immediately after modifying existing code (functions, classes, imports, etc.)
Immediately after completing a feature, refactor, or bug fix
Before staging files for commit
When build/compilation succeeds but linting hasn't been checked
Proactively, whenever code changes are made

Don't use:

When you've already run linting and it passed

Linter Discovery

First look for linting commands in the following order:

Directives to AI agents (CLAUDE.md, .cursorrules, .ai-rules, AGENTS.md, AGENT.md, GEMINI.md, and similar)
Repository documentation (README.md, docs/, etc.)
Package configuration (package.json, Makefile, pyproject.toml, etc.)
Standard linter patterns for the project type

If no linting guidelines are found or they are unclear, ask the user for clarification.

Common Linter Commands

# JavaScript/TypeScript
npm run lint
yarn run lint
pnpm run lint
npx eslint .

# Python
ruff check .
pylint .
flake8 .
black --check .
make lint

# Shell
shellcheck .

# Multiple/Generic
npm run format
yarn run format
pnpm run format

Linting Process

For each linter found:

If it has an auto-fix mode (e.g., prettier, eslint --fix, black, ruff check --fix), run that first
Run the linter in check mode to see if there are any remaining issues
If issues can't be fixed automatically, report them clearly

Important Rules

CRITICAL: Do NOT ignore unfixed issues!

All linting issues MUST be resolved before considering the task complete
The only exception is if the user explicitly gives permission to defer resolution
Document any issues that couldn't be auto-fixed for the user to review

Output

Report results organized by:

Auto-fixed issues: What was automatically corrected
Remaining issues: Issues requiring manual attention (list each with file, line, and description)
Recommendation: What the developer should do next

If all linting passes, simply confirm: "All linters passed."