Increase visibility of rendering issues

[ravinggenius]

If my view contains {{foo.bar.baz}}, and foo is never defined, an empty string gets rendered. This is fine for production, but it obscures errors and increases difficulty during development. Does Angular have a setting that can be enabled to dump rendering issues to the console? Ideally each dump should communicate the invalid expression, why it is invalid, where the expression was encountered and anything else that might be pertinent.

[pkozlowski-opensource]

AngularJS expressions (http://docs.angularjs.org/guide/expression) are:

Forgiving: expression evaluation is forgiving to undefined and null, unlike in JavaScript, where trying to evaluate undefined properties can generate ReferenceError or TypeError.

AFAIK currently there is no such setting and having forgiving evaluation is really handy for many use-cases. At the same time I agree that it might make it harder to track down errors or have typo errors going unnoticed. Maybe a setting for the $parser would be a solution here...

[caitp]

Yeah, so this is a feature request, which might be nice, and probably wouldn't be very difficult to implement (although, more difficult as long as promise unwrapping still exists). It might unfortunately still be a lot of code to add (because of the unwrapped loops in the parser), but the actual code to add should be pretty simple.

[tbosch]

This would be too much for Angular 1.x, sorry.
However, we should consider it for Angular 2. Something like: throw if a value is null (as that was obviously set directly), but don't throw if it is undefined...