Mastering TypeScript Skill

Master enterprise-grade TypeScript development with type-safe patterns, modern tooling, and framework integration.

Overview

This skill provides comprehensive guidance for TypeScript 5.9+ development, covering:

• Type System Mastery: Generics, mapped types, conditional types, satisfies operator
• Enterprise Patterns: Error handling, validation with Zod, project architecture
• React Integration: Type-safe components, hooks, state management (Zustand, Redux Toolkit)
• NestJS Development: Scalable APIs, DTOs, authentication, RBAC
• Modern Toolchain: Vite 7, pnpm, ESLint 9 flat config, Vitest
• Cross-Language Insights: TypeScript compared with Java, Python, C#

Quick Start

# Initialize TypeScript project with ESM
pnpm create vite@latest my-app --template vanilla-ts
cd my-app && pnpm install

# Configure strict TypeScript
cat > tsconfig.json << 'EOF'
{
  "compilerOptions": {
    "target": "ES2024",
    "module": "ESNext",
    "moduleResolution": "bundler",
    "strict": true,
    "noUncheckedIndexedAccess": true,
    "exactOptionalPropertyTypes": true
  }
}
EOF

When to Use This Skill

Use when:

• Building type-safe React, NestJS, or Node.js applications
• Migrating JavaScript codebases to TypeScript
• Implementing advanced type patterns (generics, mapped types, conditional types)
• Configuring modern TypeScript toolchains
• Designing type-safe API contracts with Zod validation

Installing with Skilz (Universal Installer)

The recommended way to install this skill across different AI coding agents is using the skilz universal installer.

Install Skilz

pip install skilz

Claude Code

Install to user home (available in all projects):

skilz install -g https://github.com/SpillwaveSolutions/mastering-typescript-skill

Install to current project only:

skilz install -g https://github.com/SpillwaveSolutions/mastering-typescript-skill --project

OpenCode

skilz install -g https://github.com/SpillwaveSolutions/mastering-typescript-skill --agent opencode

Gemini

skilz install -g https://github.com/SpillwaveSolutions/mastering-typescript-skill --agent gemini

OpenAI Codex

skilz install -g https://github.com/SpillwaveSolutions/mastering-typescript-skill --agent codex

Skill Contents

• SKILL.md - Main skill documentation with quick reference
• references/ - Detailed reference documentation
  • type-system.md - Complete type system guide
  • generics.md - Advanced generics patterns
  • enterprise-patterns.md - Error handling, validation, architecture
  • react-integration.md - React + TypeScript patterns
  • nestjs-integration.md - NestJS API development
  • toolchain.md - Modern build tools configuration
• assets/ - Templates and starter files
  • tsconfig-template.json - Strict enterprise config
  • eslint-template.js - ESLint 9 flat config
• scripts/ - Utility scripts
  • validate-setup.sh - Verify TypeScript environment

Version Information (December 2025)

| Tool | Version | Purpose | |------|---------|---------| | TypeScript | 5.9+ | Type checking and compilation | | Node.js | 22 LTS | Runtime environment | | Vite | 7.x | Build tool and dev server | | pnpm | 9.x | Package manager | | NestJS | 11.x | Backend framework | | React | 19.x | Frontend library | | ESLint | 9.x | Linting with flat config | | Vitest | 3.x | Testing framework |

Key Features Covered

Type System

• Union and intersection types
• Discriminated unions for type-safe branching
• Type guards and type narrowing
• The satisfies operator for safer type checking
• Template literal types

Generics

• Generic functions, interfaces, and classes
• Generic constraints with extends
• Mapped types and key remapping
• Conditional types with infer
• Variadic tuple types

Enterprise Patterns

• Result/Either types for error handling
• Zod schema validation
• Branded types for domain modeling
• Feature-based project organization

Framework Integration

• React: Typed components, hooks, Context API
• NestJS: Controllers, services, DTOs, guards
• State management: Zustand, Redux Toolkit

License

MIT

Author

Richard Hightower - Based on "Mastering Modern TypeScript" book content