Advanced TypeScript Patterns for Better Code

# Advanced TypeScript Patterns

TypeScript offers powerful features that go beyond basic type annotations. Let's explore advanced patterns that can make your code more robust and maintainable.

## Generic Constraints

```typescript interface Identifiable { id: string; }

function updateEntity<T extends Identifiable>( entity: T, updates: Partial<T> ): T { return { ...entity, ...updates }; } ```

## Conditional Types

```typescript type ApiResponse<T> = T extends string ? { message: T } : { data: T };

// Usage type StringResponse = ApiResponse<string>; // { message: string } type UserResponse = ApiResponse<User>; // { data: User } ```

## Utility Types

```typescript // Pick specific properties type UserSummary = Pick<User, 'id' | 'name' | 'email'>;

// Make all properties optional type PartialUser = Partial<User>;

// Make all properties required type RequiredUser = Required<User>; ```

## Template Literal Types

```typescript type EventName = `on${Capitalize<string>}`; type ClickEvent = `click${string}`;

// Usage const eventName: EventName = 'onClick'; // ✅ const clickEvent: ClickEvent = 'clickButton'; // ✅ ```

These patterns help create more expressive and type-safe APIs.