ES6 import typo

actionTypes.js

export const UPDATE_REQUEST = 'UPDATE_REQUEST';

reducer.js

import * as types from '../constants/actionTypes';

export default function pouchdbReducer(state = {}}, action) {
  switch (action.type) {
    case types.UPDDATE_REQUEST:
      // there is a typo above which evaluates to `undefined`
      // this code would never be reached - how to make it an error
      return Object.assign({}, state, {updated: true});
    default:
      return state;
  }
}

case types.UPDDATE_REQUEST.toString():

would raise TypeError if it is undefined.