Bun

Bun is a JavaScript runtime, test runner, and bundler. Even teams shipping Node-targeted libraries increasingly use Bun for the dev loop. repo-tooling ships a Bun-typed TypeScript preset and a bunfig.toml template so bun test / bun run work against the same source tree.

Bun support is opt-in and additive — it doesn't change your package manager, build, or release setup. Most consumers still target Node-compatible libraries and just want Bun's fast dev loop.

Usage

New projects — the setup wizard asks "Target the Bun runtime?" for library and Node-API projects. Answer yes and it emits bunfig.toml and a Bun-typed tsconfig.json as part of the scaffold (or set "bun": true in a --config file).

Existing projects — scaffold the Bun toolchain files with the fixer:

npx @rtorcato/repo-tooling fix bun

This is safe-add — it writes:

• bunfig.toml — only if one doesn't already exist.
• tsconfig.json extending the Bun preset — only when no tsconfig.json exists yet. In an existing project, point your tsconfig at the preset by hand (below).

Install Bun's types:

bun add -d @types/bun

TypeScript preset

The Bun preset extends the shared base and adds types: ["bun"]:

// tsconfig.json
{ "extends": "@rtorcato/repo-tooling/typescript/bun" }

which resolves to:

{
  "extends": "./tsconfig.base.json",
  "compilerOptions": {
    "lib": ["ES2022"],
    "types": ["bun"]
  },
  "include": ["src", "index.d.ts"],
  "exclude": ["node_modules", "dist", "build", "test", "**/*.test.ts", "**/*.spec.ts"]
}

bunfig.toml

A minimal, library-friendly default — tune to taste:

[install]
frozenLockfile = false
exact = true

[test]
coverage = false
root = "."

Testing under Bun

You have two options:

• bun test — Bun's built-in Jest-style runner. Fast, zero-config, uses the bun:test API. Good when Bun is your primary runtime.
• Vitest under Bun — Vitest runs under Bun (bun run vitest), so the shipped Vitest preset works unchanged if you want a single test runner across Node and Bun. This is the safer choice for libraries that must also pass on Node CI.

Import path

Export	Use case
@rtorcato/repo-tooling/typescript/bun	Bun-typed tsconfig (types: ["bun"])