You might have used redux with react as it is a very common practice. Many people use redux-saga or redux-thunk for async actions as middlewares. Redux allows you to create your own custom middleware as per your requirement. A middleware can be added in between dispatch and reducers, so that we can alter the actions or can dispatch other actions (for async actions).
This is done with a function returning function. So, lets first understand about function returning function.
it is simple and done as follows –
A service worker, simply, is a script that runs in the background and do not require the web page to load. It runs on separate thread and can not directly access the DOM. It interacts with webpages through post messages.
Service worker are asyncronous and can not use XHR and localStorage inside it.
As of this writing, Concurrent mode is experimental. It allows the rendering process interuptible. It doesn’t block the browser from making changes to the DOM, and continues rendering in memory.
The performance of an Application can be good or bad depending on the quality of code. In React, The Profiler API helps in measuring the performance of a component and to improve it.
The Profiler API for DevTools first got shipped in the 16.5 React version. It helps developers find difficulties in your web application. In 16.9 version, the React team has gone a step further to enhance the API.