Type Alias DeepReadonly<T>

DeepReadonly: T extends Date
| RegExp
| Error
    ? T
    : T extends (...args: infer A) => infer R
        ? (...args: A) => R
        : T extends readonly (infer U)[]
            ? readonly DeepReadonly<U>[]
            : T extends object ? { readonly [K in keyof T]: DeepReadonly<T[K]> } : T