Create a new intersection type from an existing type

create-intersection-type.ts

type Foo = {
  prop1: {
    value: string;
  };
  prop2: {
    value: string[];
  };
  prop3: {
    value: number;
  };
  prop4: {
    value: number[];
  };
};

/** Create a new intersection type from an existing type */
type IntersectProps<T, TKey extends keyof T> = {
  [K in TKey]: (arg: T[K]) => void;
}[TKey] extends (arg: infer V) => void
  ? V
  : never;

type Intersected = IntersectProps<Foo, keyof Foo>;
//   ^?

/** Intersected is:
type Intersected = {
    value: string;
  } & {
      value: string[];
  } & {
      value: number;
  } & {
      value: number[];
  }
 */