exception thrown in module during req.exec can break module loading by leaving isCheckLoaded = true about requirejs

[asutherland]

er, ignore my claim that isCheckLoaded clearing on line 1245 is what is failing to happen; I don't have enough evidence for that (there are a number of places it could get cleared) and am going to shirk on providing it. But the callstack and general problem of isCheckLoaded ending up stuck on true still hold.

[asutherland]

And seeing how inadequate just catching everything and feeding it into a console.error is (I'm doing that in my hack fix), I guess I would propose perhaps just re-throwing the exception after cleaning up when the cleanup is feasible. If cleanup is not feasible, console.error-ing that module loading is now wedged could be useful.

In terms of defining feasible, in this case where I am doing a dynamic require and my callback is the thing that is breaking, not the execution of any loaded module, I would define that as feasible to cleanup. If the thing I was requiring broke, I am fine with calling that a potentially forever-wedging event, although it might be nice if other requires that didn't involve the wedged module could keep on going.

A non-debugger-UI use-case would be an application UI that dynamically loads functionality. Just because one menu item is now broken does not mean that the rest of the UI should crash and burn.

[jrburke]

I am working on a refactor branch, where I want to execute module factory functions as soon as they are available, and I would like to pick up support for what you suggest as part of that. That refactor branch may not be completed for a few weeks though, so if this is useful to have for you now, I can put in a fix for it sooner.

[jrburke]

I believe this is better in the 1.0 code, with the ability to catch errors and have the code in a state where some modules are still usable.