TypeScript 고급 타입 패턴 정리

Mapped Types

기존 타입을 변환해 새로운 타입을 만드는 패턴입니다.

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

type Partial = {
  [P in keyof T]?: T[P]
}

Conditional Types

type NonNullable = T extends null | undefined ? never : T

type ReturnType = T extends (...args: any[]) => infer R ? R : never

Template Literal Types

type EventName = "click" | "focus" | "blur"
type Handler = `on${Capitalize}`
// "onClick" | "onFocus" | "onBlur"