Make the angular-app more fault tolerant?



Our app sometimes gets into an odd error state, where it isn’t exactly crashed but it isn’t working either.

For instance, I just solved a bug in one of our rxjs/Observables.
We tested for “query.items.length” but unfortunately query.item is sometimes undefined, so that throw an error.
This caused the app to be unusable, the view was empty, I couldn’t switch tabs or pages, but it was still running.
And that is a horrible user experience, it might be better for it to just crash.

My question is, what the best way to handle something like that?
Do we really need to set an .catch on every single Observable chain, just in-case where is an error?