gesetz

Gesetz

Gesetz (German for "laws") — a unified code-quality gate that lets you write your own project rules as easily as writing a config file.

View the full documentation on GitHub

Why Gesetz exists

Every codebase has conventions that no generic linter knows about:

• "Every module in src/ must have a README.md"
• "No file should exceed 400 lines"
• "No one should import from src/legacy/ — we're migrating away"
• "Every API endpoint file needs a sibling .test.ts"
• "Console logs left in production code break our log pipeline"
• "Feature A must not import internals from Feature B"

ESLint, PHPStan, and Vitest are excellent at what they do. But they don't know your architecture. Gesetz bridges that gap: you write project-specific rules in plain TypeScript, and Gesetz runs them alongside your existing tools in a single, scored report.

Gesetz does not replace your linters. It wraps them. You still run ESLint, Vitest, PHPStan — but their output and your custom rules all feed into one unified Violation format, one category score, one CLI. Because the rule engine is language-agnostic, the same gesetz check covers your TypeScript frontend, your PHP backend, and whatever else lives in the repo.

Category	What it measures
strictness	Type safety, any, as, non-null assertions, floating promises
structure	Code shape: file/function size, nesting, magic numbers, empty catch blocks
organization	Monorepo health: cycles, layer violations, import discipline, file pairing
cleanup	Dead code, AI residue: console logs, trivial comments, debugging files
security	Secrets, SQL injection, unsafe innerHTML, hardcoded tokens

Categories are extensible — category is just a string, so you can define your own (e.g. category: 'api-conventions' or category: 'react').

The goal is simple: one command, one score, one decision. Pass or fail.

Quick start

1. Install Gesetz and the adapters you need

# Core + CLI (lightweight — no heavy deps)
bun add -d gesetz

# Adapters for your stack (install only what you use)
bun add -d @gesetz/eslint @gesetz/vitest @gesetz/typescript

2. Initialize a config

gesetz init

This creates a gesetz.config.ts at your project root. In a TTY it runs an interactive wizard; in CI or agent mode it auto-detects your framework and installed tools.

3. Run checks

gesetz check

Output (TTY):

┌─────────────┬───────┬────────┬─────────┬─────────┐
│ Category    │ Score │ Errors │ Warns   │ Infos   │
├─────────────┼───────┼────────┼─────────┼─────────┤
│ strictness  │ 9.0   │ 0      │ 2       │ 0       │
│ structure   │ 7.5   │ 1      │ 5       │ 0       │
│ cleanup     │ 10.0  │ 0      │ 0       │ 0       │
└─────────────┴───────┴────────┴─────────┴─────────┘
✅ All categories above threshold

License

MIT

Lukas Mateffy