dictionary.js

const dictionary = {};
// Add keys to the dictionary
dictionary['REQUEST_SHOW_FINISHED'] = (state, payload) => {
  return {
    ...state,
    show: payload,
  }
};
dictionary['REQUEST_EPISODES_FINISHED'] = (state, payload) => {
  return {
    ...state,
    episodes: payload,
  }
};
dictionary['REQUEST_CAST_FINISHED'] = (state, payload) => {
  return {
    ...state,
    actors: payload,
  }
};
// Usage
const newState = dictionary[action.type](state, action.payload); // Warning: This will break if the action.type is not found