Typescript Type Utils

type-utils.ts

export type WithOptional<T, K extends keyof T> = Pick<Partial<T>, K> & Omit<T, K>;

export type Expand<T> = T extends infer O ? { [K in keyof O]: O[K] } : never;

// expands object types recursively
export type ExpandRecursively<T> = T extends object
  ? T extends infer O
    ? { [K in keyof O]: ExpandRecursively<O[K]> }
    : never
  : T;

export type DeepPartial<T> = {
    [P in keyof T]?: T[P] extends object ? DeepPartial<T[P]> : T[P];
};