redux profiler

store.js

//...store logic

// profiler for redux actions
const userTiming = (store) => (next) => (action) => {
    if (performance.mark === undefined) return next(action)
    performance.mark(`${action.type}_start`);
    const result = next(action);
    performance.mark(`${action.type}_end`);
    performance.measure(`${action.type}`,`${action.type}_start`,`${action.type}_end`,)
    return result
}
// add to middleware
let middleware = [thunk]
if (__DEV__) middleware.push(userTiming)