Mastering TypeScript in 2026

TypeScript has become the de facto standard for building large-scale JavaScript applications. Let's explore advanced patterns and best practices.

Why TypeScript?

• Type Safety: Catch errors at compile time
• Better IDE Support: Enhanced autocomplete and refactoring
• Self-Documenting Code: Types serve as inline documentation
• Scalability: Easier to maintain large codebases

Advanced Type Patterns

Conditional Types

type IsString<T> = T extends string ? true : false;

type A = IsString<'hello'>; // true
type B = IsString<42>; // false

Mapped Types

type Readonly<T> = {
  readonly [P in keyof T]: T[P];
};

type Optional<T> = {
  [P in keyof T]?: T[P];
};

Template Literal Types

type EventName<T extends string> = `on${Capitalize<T>}`;

type ClickEvent = EventName<'click'>; // 'onClick'
type HoverEvent = EventName<'hover'>; // 'onHover'

Best Practices

1. Enable Strict Mode: Use strict: true in tsconfig.json
2. Avoid any: Use unknown instead when type is truly unknown
3. Leverage Type Inference: Let TypeScript infer types when possible
4. Use Discriminated Unions: For better type narrowing

Conclusion

TypeScript's type system is powerful and expressive. Mastering these patterns will help you build more robust applications.