Slightly better error reporting for coffeescript.

[tmeasday]

Fixes #331

I just copied what the less package does. Not sure why, but it seems to try to compile the file twice.

[glasser]

The "compile file twice" is presumably referring to .coffee files that are in the main app dir, and thus are compiled once for client and once for server. (While the compilation is identical in both cases, one could imagine register_extension handlers that do significantly different things on client and server.)

[glasser]

I like to try to keep the scope of a try/catch as small as possible, so I'd just wrap the "contents = " line in the try/catch, or in fact even just the "coffee.compile" call and move new Buffer to its own line. That way, an exception through during "new Buffer" or "bundle.add_resource" won't confusingly be described as a Coffeescript compiler error. I realize that you are using the "less" package as inspiration, but that call uses an asynchronous callback, so in fact even though it physically looks similar to what you've written here, the try/catch really is only surrounding the less.render call.

That said, taking a peek at the coffeescript source, it looks like if you add a "filename" key to the "options" object, coffeescript itself will include the filename in all errors.

[tmeasday]

@glasser Thanks for looking at this properly. This much simpler change works. So my question now is: should we be catching CS's error and doing bundle.error, or should we let it blow meteor up like it does right now?

[glasser]

Oh, good point. So you probably want something like
try {
var compiled = coffee.compile(...);
} catch (e) {
bundle.error(e.message);
return;
}

[tmeasday]

Does that seem reasonable?