Typescript Docs

# TypeScript Documentation

Generate production-ready TypeScript documentation with layered architecture for multiple audiences. Supports API docs with TypeDoc, ADRs, and framework-specific patterns.

## Overview

Use JSDoc annotations for inline documentation, TypeDoc for API reference generation, and ADRs for tracking design choices.

**Key capabilities:**
- TypeDoc configuration and API documentation generation
- JSDoc patterns for all TypeScript constructs
- ADR creation and maintenance
- Framework-specific patterns (NestJS, React, Express, Angular, Vue)
- ESLint validation rules for documentation quality
- GitHub Actions pipeline setup

## When to Use

Use this skill when creating API documentation, architectural decision records, code examples, or framework-specific patterns for NestJS, Express, React, Angular, or Vue.

## Quick Reference

| Tool | Purpose | Command |
|------|---------|---------|
| TypeDoc | API documentation generation | `npx typedoc` |
| Compodoc | Angular documentation | `npx compodoc -p tsconfig.json` |
| ESLint JSDoc | Documentation validation | `eslint --ext .ts src/` |

### JSDoc Tags

| Tag | Use Case |
|-----|----------|
| `@param` | Document parameters |
| `@returns` | Document return values |
| `@throws` | Document error conditions |
| `@example` | Provide code examples |
| `@remarks` | Add implementation notes |
| `@see` | Cross-reference related items |
| `@deprecated` | Mark deprecated APIs |

## Instructions

### 1. Configure TypeDoc

```bash
npm install --save-dev typedoc typedoc-plugin-markdown
```

```json
{
  "entryPoints": ["src/index.ts"],
  "out": "docs/api",
  "theme": "markdown",
  "excludePrivate": true,
  "readme": "README.md"
}
```

### 2. Add JSDoc Comments

```typescript
/**
 * Service for managing user authentication
 *
 * @remarks
 * Handles JWT-based authentication with bcrypt password hashing.
 *
 * @example
 * ```typescript
 * const authService = new AuthService(config);
 * const token = await authService.login(email, password);
 * ```
 *
 * @security
 * - Passwords hashed with bcrypt (cost factor 12)
 * - JWT tokens signed with RS256
 */
@Injectable()
export class AuthService {
  /**
   * Authenticates a user and returns access tokens
   * @param credentials - User login credentials
   * @returns Authentication result with tokens
   * @throws {InvalidCredentialsError} If credentials are invalid
   */
  async login(credentials: LoginCredentials): Promise<AuthResult> {
    // Implementation
  }
}
```

### 3. Create an ADR

```markdown
# ADR-001: TypeScript Strict Mode Configuration

## Status
Accepted

## Context
What is the issue motivating this decision?

## Decision
What change are we proposing?

## Consequences
What becomes easier or more difficult?
```

### 4. Set Up CI/CD Pipeline

```yaml
name: Documentation
on:
  push:
    branches: [main]
    paths: ['src/**', 'docs/**']

jobs:
  generate-docs:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: '20'
          cache: 'npm'
      - run: npm ci
      - run: npm run docs:generate
      - run: npm run docs:validate
```

### 5. Validate Documentation

```json
{
  "rules": {
    "jsdoc/require-description": "error",
    "jsdoc/require-param-description": "error",
    "jsdoc/require-returns-description": "error",
    "jsdoc/require-example": "warn"
  }
}
```

**If validation fails:** review ESLint errors, fix JSDoc comments (add missing descriptions, add `@param`/`@returns`/`@throws` where absent), re-run `eslint --ext .ts src/` until