It was quite common for Sitecore MVC implementation to add logic around renderings that will catch unexpected exceptions in them and save your page from complete collapse. Such logic hides your component from end users and might only put something in HTML comments, while during preview or editing experience it will give some visual indication of an error and its details.
Such functionality can also be very useful for React JSS applications, but it is not that simple especially on for isomorphic apps leveraging SSR (server-side rendering).
jss
Mixing Sitecore JSS and SXA
This investigation of Sitecore JSS and SXA was done quite a while ago, but I didn’t get a chance to post it here. I need to go back to validation of this setup so this will be a living post and I’ll be updating as new findings arrive.
You might ask why would you need to mix them, but the reason is pretty simple. SXA brings a lot of functionality outside of presentation configuration (which I’m not a fan of) that can be useful for any site, like sites management, wizards for sites creation, local data sources, various site settings, etc.