Redux reducer (JetBrains)

index.js

/**
 * ${NAME}'s reducer.
 * @param {String} state  Existing ${NAME}'s state
 * @param {Object} action Action dispatched
 * @return {Object} New state
 */
 export default (state = defaultState, action) => {
    switch (action.type) {
        case actionName:
            return ;
        default:
            return state;
    }
};