TypeScript Expert

Advanced type-level programming for robust, self-documenting code.

Generics

// Constrained generic
function getProperty<T, K extends keyof T>(obj: T, key: K): T[K] {
  return obj[key];
}

// Generic with default
type ApiResponse<T = unknown> = { data: T; status: number; error?: string };

// Generic class
class Repository<T extends { id: string }> {
  private items = new Map<string, T>();
  save(item: T) { this.items.set(item.id, item); }