atelier-typescript-build-tools skill

---
name: atelier-typescript-build-tools
description: TypeScript project tooling with Bun, tsgo, Vitest, Biome, and Turborepo. Use when setting up package.json scripts, running builds, typechecking, configuring tests, linting, formatting, or orchestrating monorepo development.
user-invocable: false
---

# TypeScript Build Tools

Modern TypeScript build tooling stack: Bun for package management and task running, tsgo for typechecking, Vitest for testing, Biome for linting/formatting, and Turborepo for monorepo orchestration.

## Additional References

- [references/bun.md](./references/bun.md) - Bun package manager and task runner
- [references/vitest.md](./references/vitest.md) - Advanced Vitest configuration patterns
- [references/biome.md](./references/biome.md) - Biome rules and customization
- [references/turborepo.md](./references/turborepo.md) - Turborepo monorepo orchestration

## Quick Start

```bash
# Install dependencies
bun add -D vitest @vitest/coverage-v8 @biomejs/biome

# For monorepos
bun add -D turbo
```

## Package.json Scripts

### Single Package

```json
{
  "scripts": {
    "dev": "bun run --watch src/index.ts",
    "build": "bun build ./src/index.ts --outdir ./dist --target bun",
    "typecheck": "tsgo --noEmit",
    "test": "vitest run",
    "test:watch": "vitest",
    "test:coverage": "vitest run --coverage",
    "lint": "biome check .",
    "lint:fix": "biome check --write .",
    "format": "biome format --write .",
    "check": "bun run typecheck && bun run lint && bun run test"
  }
}
```

### Monorepo Root

```json
{
  "scripts": {
    "dev": "turbo dev",
    "build": "turbo build",
    "typecheck": "turbo typecheck",
    "test": "turbo test",
    "lint": "turbo lint",
    "check": "turbo typecheck lint test"
  }
}
```

## Bun

### Package Manager

```bash
# Install dependencies
bun install

# Add dependencies
bun add fastify drizzle-orm
bun add -D vitest @biomejs/biome

# Remove dependency
bun remove package-name

# Update dependencies
bun update
```

### Task Runner

**Important:** Use `bun run test` (not `bun test`) on Node projects. `bun test` invokes Bun's native test runner, not your package.json test script.

```bash
# Run script from package.json
bun run dev
bun run test
bun run build

# Run TypeScript directly (no build step)
bun run src/index.ts

# Watch mode
bun run --watch src/index.ts

# With environment variables
bun run --env-file .env src/index.ts
```

### Build Command

```bash
# Basic build for Bun runtime
bun build ./src/index.ts --outdir ./dist --target bun

# For Node.js runtime
bun build ./src/index.ts --outdir ./dist --target node

# With minification
bun build ./src/index.ts --outdir ./dist --target bun --minify

# Multiple entry points
bun build ./src/index.ts ./src/worker.ts --outdir ./dist --target bun
```

See [references/bun.md](./references/bun.md) for bunfig.toml configuration and advanced patterns.

## tsgo Typechecking

tsgo is a fast TypeScript typechecker. Use it instead of `tsc` for faster CI builds.

```bash
# Typecheck without emitting
tsgo --noEmit

# Typecheck specific files
tsgo --noEmit src/**/*.ts

# With project reference
tsgo --noEmit -p tsconfig.json
```

### tsconfig.json

```json
{
  "compilerOptions": {
    "target": "ESNext",
    "module": "ESNext",
    "moduleResolution": "bundler",
    "strict": true,
    "skipLibCheck": true,
    "noEmit": true,
    "esModuleInterop": true,
    "resolveJsonModule": true,
    "isolatedModules": true,
    "verbatimModuleSyntax": true,
    "lib": ["ESNext"],
    "types": ["bun-types"]
  },
  "include": ["src/**/*.ts"],
  "exclude": ["node_modules", "dist"]
}
```

## Vitest

### Basic Configuration

```typescript
// vitest.config.ts
import { defineConfig } from 'vitest/config'

export default defineConfig({
  test: {
    globals: true,
    environment: 'node',
    include: ['src/**/*.test.ts', 'test/**/*.test.ts'],
    coverage: {
      provider: 'v8',
      reporter: ['text', 'json', 'html'],
      include: ['src/**/*.ts'],
      exclude: ['src/**/*.test.ts', 'src/types/**'],
    },
  },
})
```

### With Path Aliases

```typescript
// vitest.config.ts
import { defineConfig } from 'vitest/config'
import tsconfigPaths from 'vite-tsconfig-paths'

export default defineConfig({
  plugins: [tsconfigPaths()],
  test: {
    globals: true,
  },
})
```

### Global Setup (Database Migrations)

```typescript
// vitest.config.ts
import { defineConfig } from 'vitest/config'

export default defineConfig({
  test: {
    globals: true,
    globalSetup: './test/global-setup.ts',
    setupFiles: ['./test/setup.ts'],
  },
})
```

```typescript
// test/global-setup.ts
import { execSync } from 'node:child_process'

export async function setup() {
  console.log('Running database migrations...')
  execSync('drizzle-kit migrate', { stdio: 'inherit' })
}

export async function teardown() {
  console.log('Test teardown complete')
}
```

See [references/vitest.md](./references/vitest.md) for workspace configs, benchmarks, and Cloudflare Workers pool.

## Biome

### Basic biome.json

```json
{
  "$schema": "https://biomejs.dev/schemas/2.0.0/schema.json",
  "vcs": {
    "enabled": true,
    "clientKind": "git",
    "useIgnoreFile": true
  },
  "files": {
    "ignoreUnknown": true,
    "ignore": ["dist", "node_modules", "*.gen.ts"]
  },
  "formatter": {
    "enabled": true,
    "indentStyle": "tab",
    "lineWidth": 100
  },
  "javascript": {
    "formatter": {
      "quoteStyle": "double",
      "trailingCommas": "es5"
    }
  },
  "linter": {
    "enabled": true,
    "rules": {
      "recommended": true
    }
  },
  "organizeImports": {
    "enabled": true
  }
}
```

### Strict Rules (Production)

```json
{
  "linter": {
    "enabled": true,
    "rules": {
      "recommended": true,
      "complexity": {
        "noForEach": "error"
      },
      "performance": {
        "noDelete": "error"
      },
      "style": {
        "useNodejsImportProtocol": "error"
      }
    }
  }
}
```

See [references/biome.md](./references/biome.md) for rule explanations, shareable configs, and CLI commands.

## Turborepo (Monorepo)

### turbo.json

```json
{
  "$schema": "https://turbo.build/schema.json",
  "tasks": {
    "build": {
      "dependsOn": ["^build"],
      "outputs": ["dist/**"]
    },
    "typecheck": {
      "dependsOn": ["^typecheck"]
    },
    "lint": {},
    "test": {
      "dependsOn": ["^build"],
      "env": ["DATABASE_URL"]
    },
    "dev": {
      "cache": false,
      "persistent": true
    }
  }
}
```

### Workspace Structure

```
my-monorepo/
├── package.json          # Root with turbo scripts
├── turbo.json            # Turbo configuration
├── biome.json            # Shared Biome config
├── packages/
│   ├── config-biome/     # Shareable Biome package
│   └── shared/           # Shared utilities
├── apps/
│   ├── api/              # Fastify API
│   └── web/              # React app
└── bun.lock
```

See [references/turborepo.md](./references/turborepo.md) for caching strategies, filtering, and CI setup.

## Cloudflare Workers

### Vite + Cloudflare Plugin

```typescript
// vite.config.ts
import { cloudflare } from '@cloudflare/vite-plugin'
import { reactRouter } from '@react-router/dev/vite'
import tailwindcss from '@tailwindcss/vite'
import tsconfigPaths from 'vite-tsconfig-paths'
import { defineConfig } from 'vite'

export default defineConfig({
  plugins: [
    cloudflare({ viteEnvironment: { name: 'ssr' } }),
    tailwindcss(),
    reactRouter(),
    tsconfigPaths(),
  ],
})
```

### Vitest with Cloudflare Workers Pool

```typescript
// vitest.config.ts
import { defineWorkersConfig } from '@cloudflare/vitest-pool-workers/config'

export default defineWorkersConfig({
  test: {
    globals: true,
    pool: '@cloudflare/vitest-pool-workers',
    poolOptions: {
      workers: {
        wrangler: { configPath: './wrangler.jsonc' },
      },
    },
  },
})
```

## CI Pipeline

### GitHub Actions

```yaml
name: CI

on:
  push:
    branches: [main]
  pull_request:

jobs:
  check:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - uses: oven-sh/setup-bun@v2
        with:
          bun-version: latest

      - run: bun install --frozen-lockfile

      - run: bun run typecheck
      - run: bun run lint
      - run: bun run test
```

### Monorepo CI with Turbo

```yaml
name: CI

on:
  push:
    branches: [main]
  pull_request:

jobs:
  check:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - uses: oven-sh/setup-bun@v2

      - run: bun install --frozen-lockfile

      - run: bun run check  # turbo typecheck lint test
        env:
          TURBO_TOKEN: ${{ secrets.TURBO_TOKEN }}
          TURBO_TEAM: ${{ vars.TURBO_TEAM }}
```

## Guidelines

1. **Use Bun** as package manager (`bun install`) and task runner (`bun run`)
2. **Use `bun run test`** (not `bun test`) - `bun test` runs Bun's native test runner
3. **Use tsgo** for typechecking - faster than `tsc` for CI
4. **Use Vitest** for testing - fast, ESM-native, great DX
5. **Use Biome** for linting and formatting - single tool, fast
6. **Use Turborepo** for monorepos - caching, parallel execution
7. **Enable V8 coverage** in Vitest for accurate coverage reports
8. **Configure global setup** for database migrations in tests
9. **Use workspace configs** in Vitest for different test pools
10. **Share Biome config** via workspace package in monorepos
11. **Run checks in order**: typecheck, lint, test (fail fast)
12. **Use `--frozen-lockfile`** in CI for reproducible builds
13. **Configure Turbo caching** for faster CI with remote cache