Coffeescript/Sprockets '__extends' helper duplication

Question

I'm using rails31 & coffeescript and have defined some classes that extend from a parent class. Coffeescript adds an __extends helper method in the generated output to make this happen, problem is when using sprockets a copy of the method is added for every subclass, creating a lot of duplication.

My classes are defined in separate files, so it looks like sprockets is getting coffee to process them individually. I know there is a —join option with coffee but not sure how to use that with sprockets.

Does anyone know if it's possible to generate coffee helpers only once when using sprockets?

Answer 1

Nope. Whether you're using Sprockets or not, helpers are a one-per-file kind of deal. There's no compiler option for avoiding this duplication (--join won't do it; it just concatenates the compiled JS), and no existing JS minifier is smart enough to identify and remove the duplicates (which would require moving one instance to a global scope).

My advice would be to not worry about it. CoffeeScript uses few helpers, and they're unlikely to account for more than a tiny fraction of your code.