In the past, Javascript errors inside components used to corrupt React’s internal state and produce a corrupted UI in place. React did not provide any way to handle these errors gracefully, and could not recover from them.
An important change was introduced in React version 16. Now any uncaught Javascript error will result in unmounting the whole React component tree. This leaves no room for corrupted UIs.

Why was this change introduced? Well, the React team believes that it is a bad practice to leave a corrupted UI in place, because it may have dangerous outcomes. For example, in a bank app, it is worse to display a wrong account balance than to render nothing.

That sounds logical, but still a Javascript error in some part of the UI shouldn’t break the whole app. To solve this problem, the React team introduced a new concept called error boundary.

#react #frontend #reactjs #javascript