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

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

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

2. Add JSDoc Comments

/**

• Service for managing user authentication
• @remarks
• Handles JWT-based authentication with bcrypt password hashing.
• @example
• 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

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

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

{ "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 all errors pass before committing.

Examples

Documenting a React Hook

/**

• Custom hook for fetching paginated data
• @remarks
• This hook manages loading states, error handling, and automatic
• refetching when the page or filter changes.
• @example
• function UserList() {
• const { data, isLoading, error } = usePaginatedData('/api/users', {

• page: currentPage,
  

• limit: 10
  

• });
• if (isLoading) return <Spinner />;
• if (error) return <ErrorMessage error={error} />;
• return <UserTable users={data.items} />;
• }
• @param endpoint - API endpoint to fetch from
• @param options - Pagination and filter options
• @returns Paginated response with items and metadata */ export function usePaginatedData<T>( endpoint: string, options: PaginationOptions ): UsePaginatedDataResult<T> { // Implementation }

Documenting a Utility Function

/**

• Validates email addresses using RFC 5322 specification
• @param email - Email address to validate
• @returns True if email format is valid
• @example
• isValidEmail('user@example.com'); // true
• isValidEmail('invalid-email'); // false
• @performance
• O(n) where n is the email string length
• @see {@link https://tools.ietf.org/html/rfc5322} RFC 5322 Specification */ export function isValidEmail(email: string): boolean { const emailRegex = /^[^\s@]+@[^\s@]+.[^\s@]+$/; return emailRegex.test(email); }

NestJS Controller Documentation

/**

• REST API endpoints for user management
• @remarks
• All endpoints require authentication via Bearer token.
• Rate limiting: 100 requests per minute per user.
• @example
• curl -H "Authorization: Bearer <token>" https://api.example.com/users/123
• @security
• • All endpoints use HTTPS
• • JWT tokens expire after 1 hour
• • Sensitive data is redacted from logs / @Controller('users') export class UsersController { /*
  • Retrieves a user by ID
  • @param id - User UUID
  • @returns User profile (password excluded) */ @Get(':id') async getUser(@Param('id') id: string): Promise<UserProfile> { // Implementation } }

Best Practices

• Document Public APIs: All public methods, classes, and interfaces

• Use @example : Provide runnable examples for complex functions

• Include @throws : Document all possible errors

• Add @see : Cross-reference related functions/types

• Use @remarks : Add implementation details and notes

• Document Generics: Explain generic constraints and usage

• Include Performance Notes: Document time/space complexity

• Add Security Warnings: Highlight security considerations

• Keep Updated: Update docs when code changes

• Don't document obvious code: Focus on why, not what

Constraints and Warnings

• Private Members: Use @private or exclude from TypeDoc output

• Complex Types: Document generic constraints and type parameters

• Breaking Changes: Use @deprecated with migration guidance

• Security Info: Never include secrets or credentials in documentation

• Link Validity: Ensure @see references point to valid locations

• Example Code: All examples should be runnable and tested

• Versioning: Keep documentation in sync with code versions

References

• references/jsdoc-patterns.md — JSDoc patterns for interfaces, functions, classes, generics, and unions

• references/framework-patterns.md — Framework-specific patterns for NestJS, React, Express, and Angular

• references/adr-patterns.md — ADR templates and examples

• references/pipeline-setup.md — CI/CD pipeline configuration for documentation

• references/validation.md — ESLint rules and validation checklists

• references/typedoc-configuration.md — Complete TypeDoc configuration options

• references/examples.md — Additional code examples