pflevy-multipleIdsReducerHandler.js

export const multipleIdsReducerHandler = (reducerFunction) => (
  state = {},
  action
) => {
  const { internalReducerId } = action;
  if (internalReducerId === undefined) return state;

  const newState = reducerFunction(
    state?.byId?.[internalReducerId] || {},
    action
  );
  if (Object.keys(newState).length === 0) return state;

  return {
    ...state,
    byId: {
      ...state.byId,
      [internalReducerId]: { ...newState }
    }
  };
};