# Forge Lang Typescript

> TypeScript development standards including type checking, jest/vitest, eslint, and prettier. Use when working with TypeScript files, tsconfig.json, or .ts/.tsx files. Use when this capability is needed.

- Skill: `tomevault-io/forge-lang-typescript` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add tomevault-io/forge-lang-typescript`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/forge-lang-typescript/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: tomevault-io (https://skillmd.com/u/tomevault-io)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/tomevault-io/forge-lang-typescript

---


# TypeScript Development

## Type Checking

```bash
# Check types without emitting
npx tsc --noEmit

# Watch mode
npx tsc --noEmit --watch
```

## Testing

```bash
# Run all tests
npm test

# Run with coverage
npm test -- --coverage

# Run in watch mode
npm test -- --watch

# Run specific test
npm test -- --testPathPattern=module.test
```

## Linting

```bash
# Run eslint
npm run lint

# Fix auto-fixable issues
npm run lint -- --fix

# Type-aware linting (if configured)
npx eslint --ext .ts,.tsx src/
```

## Formatting

```bash
# Format with prettier
npm run format

# Check without changing
npx prettier --check .
```

## Project Structure

```
project/
├── src/
│   ├── index.ts
│   ├── types.ts
│   └── module.ts
├── tests/
│   └── module.test.ts
├── package.json
├── tsconfig.json
└── README.md
```

## tsconfig.json Template

```json
{
  "compilerOptions": {
    "target": "ES2022",
    "module": "NodeNext",
    "moduleResolution": "NodeNext",
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "declaration": true,
    "outDir": "./dist",
    "rootDir": "./src"
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules", "dist"]
}
```

## package.json Scripts

```json
{
  "scripts": {
    "build": "tsc",
    "test": "jest",
    "lint": "eslint src/",
    "format": "prettier --write .",
    "typecheck": "tsc --noEmit",
    "check": "npm run typecheck && npm run lint && npm run test"
  }
}
```

## TDD Cycle Commands

```bash
# RED: Write test, run to see it fail
npm test -- --testPathPattern=new_feature

# GREEN: Implement, run to see it pass
npm test -- --testPathPattern=new_feature

# REFACTOR: Clean up, ensure tests still pass
npm run check
```

---
> Converted and distributed by [TomeVault](https://tomevault.io/claim/martimramos) — claim your Tome and manage your conversions.
<!-- tomevault:4.0:skill_md:2026-04-14 -->