I'm trying to use some coffee script in an engine but as soon as i name a file with:

```
*.js.coffee or *.coffee

```

an error is triggered and i can't load the page:

```
ExecJS::RuntimeError at /mylocation
SyntaxError: unexpected IDENTIFIER

```

The page won't load. My coffeescript is working in another app (Actually i'm trying to extract the logic from the main app to an engine). When i try using it in the engine it failed if it's a .coffee file.

I have in gemfile of the core app:

```
gem 'coffee-rails'

```

In the engine gemspec:

```
s.add_dependency 'coffee-rails'

```

If i rename the file to \*.js the page loads but of course i see the syntax error in the js console. 

Any idea where i should look or what should i do to use coffeescript in my engine ?