TypeScript Best Practices for 2025

TypeScript has become the standard for building large-scale JavaScript applications. Here are modern patterns and practices to write better, more maintainable code.

Type Safety

Avoid 'any'

The 'any' type defeats the purpose of TypeScript:

• Use 'unknown' for truly unknown types
• Create proper type definitions
• Use type guards for narrowing

Strict Mode

Enable strict mode in tsconfig.json:

• Catches more potential errors
• Enforces better practices
• Improves code quality

Advanced Types

Union Types

Combine multiple types:

type Status = 'pending' | 'success' | 'error'

Intersection Types

Combine object types:

type User = Person & Employee

Utility Types

Leverage built-in utility types:

• Partial<T>
• Required<T>
• Pick<T, K>
• Omit<T, K>

Generics

Create reusable components:

function identity<T>(arg: T): T {
  return arg
}

Type Guards

Narrow types safely:

function isString(value: unknown): value is string {
  return typeof value === 'string'
}

Enums vs Union Types

Consider union types over enums:

• Better tree-shaking
• More flexible
• Simpler to use

Conclusion

Following these best practices will help you write more maintainable and type-safe TypeScript code. Keep learning and stay updated with the latest TypeScript features.