git-commit-linter

Zero-dependency CLI to lint git commit messages and enforce Conventional Commits format.

Install

npm install -g git-commit-linter

Or run without installing:

npx git-commit-linter "feat: add login page"

Usage

# Lint a message directly
git-commit-linter "feat: add login page"

# Lint from a file
git-commit-linter --file COMMIT_EDITMSG

# Use as a git hook (auto-runs on every commit)
echo "npx git-commit-linter --hook" > .git/hooks/commit-msg
chmod +x .git/hooks/commit-msg

Example output

  "feat: Add login page."

  ✗ [description-case]     Description should start with lowercase
  ⚠ [no-trailing-period]   Subject should not end with a period

  1 error(s)  1 warning(s)

What it checks

| Rule | Severity | |------|----------| | Empty commit message | error | | Doesn't follow type(scope): description format | error | | Invalid type (not in allowed list) | error | | Empty description after type | error | | Missing blank line before body | error | | Subject over 72 characters | warning | | Subject under 10 characters | warning | | Subject ends with a period | warning | | Description starts with uppercase | warning | | Body line over 100 characters | warning |

Valid types

feat fix docs style refactor perf test build ci chore revert

Valid commit examples

feat(auth): add google oauth login
fix: handle null pointer in user service
docs(readme): update installation steps
chore!: drop support for node 14
refactor(api): simplify error handling

Options

| Flag | Description | |------|-------------| | --file=PATH | Read message from a file | | --hook | Read from .git/COMMIT_EDITMSG (for git hook) | | --no-color | Disable colored output | | --help | Show help |

Exit codes

• 0 — no errors
• 1 — one or more errors (blocks the commit when used as a hook)

Running tests

npm test

License

MIT