export type ValuesType<T> = T[keyof T];

Just a small generic so I can do less typing. Otherwise it would've looked like this everywhere.

type StateEnumType = (typeof StateEnum)[keyof typeof StateEnum];

Example usage in a React useReducer.

const PointerStateEnum = {
  isMouseDown: 'isMouseDown',
  isMouseUp: 'isMouseUp',
} as const;

type PointerStateEnumType = ValuesType<typeof PointerStateEnum>;

const initialState = {
  pointerState: <PointerStateEnumType | null> null;
};

dispatch({
  type: 'SET_POINTER_STATE',
  payload: PointerStateEnum.isMouseDown,
});