Create a reducer with the cruft cut off

createReducer.js

/**
 * Creates a reducer with generic reducer logic handle for you.
 * For any cases not matched from an `action.type`, the passed state is returned.
 *
 * @author Gabe M.
 * @param {string} name - Name of the Reducer. Redux will use this for store and serialization
 * @param {Object} initialState - Initial State Object
 * @param {Object} cases - Cases is an object with describe your mutations.
 *                         Key is a matching action.type from a dispatched action.
 *                         Value is a function that accepts state, and action. This should return new non mutated state.
 *
 *
 * @example
 * createReducer('myReducer', { name: 'gabe' }, {
 *     'UPDATE_NAME': (state, action) => ({
 *         ...state,
 *         name: action.payload,
 *     })
 * })
 *
 *
 * @return {function(state, action)} genericReducer - Returns a Reducer function
 */
function createReducer(name, initialState, cases) {
    function genericReducer(state = initialState, action) {
        if (action.type in cases) {
            return cases[action.type](state, action);
        }

        return state;
    }

    genericReducer.reducerName = name;

    return genericReducer;
}