TypeScript and JavaScript

The TypeScript/JavaScript scaffold uses Bun, ESLint flat config, strict type checking for TypeScript source, coverage, dependency audit, dead-code checks, CRAP scoring, and mutation testing. It also runs the generated ESLint and test tooling across JavaScript source where those tools apply.

bun install
make check

Useful generated targets include make lint, make typecheck, make test, make coverage, make audit, make check, and make quality.

What gets wired in

Anvil adds a local ESLint plugin under tools/lint-rules/, a CRAP score reporter, Vitest coverage, Knip dead-code checks, Stryker mutation testing, security linting, gitleaks scanning, and a generated Nix shell with the tools needed to run the Makefile gates.

The TypeScript rules focus on agent failure modes: vague placeholder comments, error-obscuring catches, log-and-continue blocks, pass-through wrappers, async noise, missing tests, weak test assertions, oversized files, exported type/error/constant organization, and over-fragmented directories.

Seed/reference code

Greenfield projects receive src/seed/ with source and tests that model the generated conventions. Existing projects skip seed code when Anvil detects application code, so adoption adds guardrails without pretending your repository is empty.