Mastering TypeScript: Advanced Patterns

TypeScript's type system is incredibly powerful. Let's explore advanced patterns that will make your code more maintainable and type-safe.

Generics

Generics allow you to create reusable components:

function identity(arg: T): T {
  return arg
}
// Usage
const result = identity("hello")

Conditional Types

Create types that depend on conditions:

type IsString = T extends string ? true : false
type A = IsString  // true
type B = IsString  // false

Utility Types

TypeScript provides powerful utility types:

interface User {
  id: number
  name: string
  email: string
}
// Make all properties optional
type PartialUser = Partial
// Make all properties required
type RequiredUser = Required
// Pick specific properties
type UserPreview = Pick

Mapped Types

Transform existing types:

type Readonly = {
  readonly [P in keyof T]: T[P]
}
type ReadonlyUser = Readonly

Conclusion

These advanced TypeScript patterns will help you write more robust, maintainable code. Practice using them in your projects!