HMR ReferenceError and related errors should render as a red error on the screen

[rauchg]

Referencing a component that hasn't been imported for example is yielding only an error in the web console, which makes things tedious to debug.

[nkzawa]

We do support rendering runtime errors as a red error on the screen, but it's only when it occurred on module loading.

I wonder exactly when we should do this:

• errors on lifecycle methods of React.
• any runtime errors (maybe caches them using window.onerror)

I guess you meant about lifecycle methods ?

btw usually, we can't handle errors occurred on render of React (facebook/react#2461). We'd have to monkeypatch React.