typescript

TypeScript Development Skill

File Organization: This skill uses split structure. See references/ for advanced patterns and security examples.

1. Overview

This skill provides TypeScript expertise for the JARVIS AI Assistant, ensuring type safety across the entire codebase including Vue components, API routes, 3D rendering, and state management.

Risk Level: MEDIUM - Type system prevents runtime errors, enforces contracts, but misconfiguration can lead to security gaps

Primary Use Cases:

• Defining type-safe interfaces for JARVIS system data
• Runtime validation with Zod schemas
• Generic patterns for reusable HUD components
• Strict null checking to prevent crashes

2. Core Responsibilities

2.1 Fundamental Principles

1. TDD First: Write tests before implementation - red, green, refactor
2. Performance Aware: Apply memoization, lazy loading, and efficient patterns
3. Strict Mode Always: Enable all strict compiler options - no shortcuts
4. Explicit Types at Boundaries: Always type function parameters and return values at module boundaries
5. Runtime Validation: TypeScript types disappear at runtime - use Zod for external data
6. No Any Escape Hatch: Use unknown instead of any, then narrow with type guards
7. Immutable by Default: Prefer readonly and as const for data integrity
8. Discriminated Unions: Use tagged unions for state machines and error handling
9. Branded Types: Create nominal types for IDs and sensitive values

3. Technology Stack & Versions

3.1 Recommended Versions

Package	Version	Security Notes
typescript	^5.3.0	Latest stable with improved type inference
zod	^3.22.0	Runtime validation, schema-first
@types/node	^20.0.0	Match Node.js version

3.2 Compiler Configuration

{
  "compilerOptions": {
    "strict": true,
    "noUncheckedIndexedAccess": true,
    "noImplicitOverride": true,
    "exactOptionalPropertyTypes": true,
    "noPropertyAccessFromIndexSignature": true,
    "forceConsistentCasingInFileNames": true,
    "verbatimModuleSyntax": true,
    "moduleResolution": "bundler",
    "target": "ES2022",
    "lib": ["ES2022", "DOM", "DOM.Iterable"]
  }
}