Containing errors with error boundaries
Error boundaries allow you to handle unexpected component failures. Rather than have every component of your application know how to deal with any errors that it might encounter, error boundaries are a mechanism that you can use to wrap components with error-handling behavior. The best way to think of error boundaries is as try/catch syntax for JSX.
Let's revisit the first example from this chapter, where you fetched component data using an API function. The users() function accepts a Boolean argument, which, when true, causes the promise to reject. This is something that you'll want to handle, but not necessarily in the component that made the API call. In fact, the UserListContainer and UserList components are already set up to handle API errors like this. The challenge is that if you have lots of components, this is a lot of error-handling code. Furthermore, the error handling is specific to that one API call – what if...