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TypeScript Patterns: Writing Better Code

Exploring TypeScript patterns that can improve your codebase. From utility types to conditional types, techniques to make your code safer and more expressive.

  • TypeScript
  • Best Practices
  • Types

Introduction

TypeScript has become an essential tool in modern web development. Beyond basic typing, there are patterns and techniques that can significantly improve code quality.

Utility Types

TypeScript provides several utility types that help manipulate existing types:

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

// Required makes all properties required
type RequiredConfig = Required<Config>;

// Pick selects specific properties
type UserCredentials = Pick<User, 'email' | 'password'>;

Conditional Types

Conditional types enable us to create types based on conditions:

type ApiResponse<T> = T extends Error
  ? { success: false; error: T }
  : { success: true; data: T };

Type Guards

Type guards help narrow down types at runtime:

function isUser(obj: unknown): obj is User {
  return typeof obj === 'object'
    && obj !== null
    && 'email' in obj;
}

Conclusion

These patterns are just the beginning. TypeScript offers many more tools to create robust and type-safe applications.