naive-ui/es/_utils/naive/mutable.d.ts

A Vue 3 Component Library. Fairly Complete, Theme Customizable, Uses TypeScript, Fast

export type Mutable<T> = T extends Record<string, unknown> ? {
    -readonly [P in keyof T]: T[P] extends ReadonlyArray<infer U> ? Array<Mutable<U>> : Mutable<T[P]>;
} : T;