TypeScript continues to evolve with powerful features that enable better type safety and developer experience. This guide explores advanced patterns that will make your code more robust and maintainable.
Generic Constraints
typescript
// Constrained generics for type-safe functions
interface HasId {
id: string | number;
}
function findById<T extends HasId>(items: T[], id: T['id']): T | undefined {
return items.find(item => item.id === id);
}
// Usage with full type inference
const users = [{ id: 1, name: 'John' }, { id: 2, name: 'Jane' }];
const user = findById(users, 1); // Type: { id: number; name: string } | undefinedConditional Types
typescript
// Powerful conditional type patterns
type ApiResponse<T> = T extends null
? { success: false; error: string }
: { success: true; data: T };
type UserResponse = ApiResponse<{ name: string }>;
// { success: true; data: { name: string } }
type ErrorResponse = ApiResponse<null>;
// { success: false; error: string }80%Fewer runtime errors
100%Type safety
2xFaster refactoring
99%IDE support
