Better failure detection

[tomdale]

This commit wraps each file that gets put in vendor in a try/catch. This allows us to capture FastBoot-incompatible addons and print a much more useful error message in the console.

Note that this relies on monkeypatching Ember CLI's EmberApp method in a very hacky way. @stefanpenner thinks it may be appropriate to expose a hook that we can use instead.

[rwjblue]

Doesn't this break source maps?

[rwjblue]

I am also wondering about performance. It is my understanding that using a try catch in some cases prevent V8 from optimizing. Is that an issue here?

[stefanpenner]

Doesn't this break source maps?

Yes it will, we will have to come up with a better strategy at some point. That being said, if this is only for fast-boot builds it may be ok for awhile?

[stefanpenner]

@rwjblue it would prevent the context from being optimized, but not contexts contained within. I suspect this could affect access time of variables provided from the context with the try/catches. I don't know if we already do that in hot-paths... I am unsure as to the magnitude of the issue, some test may need to be done to see?

There is an alternative way for us to do this without try/catch, if it turns out to be a measurable issue.

function checkDeps() {
setTimeout(function() { /* check which deps have run and which haven't figuring out what went sideways */ });
}

startScript('jQuery');
// embed jQuery
endScript('jQuery');

[tomdale]

I think ember-fastboot/fastboot#16 is a better solution to this. Let's revisit if this remains a problem for people.