CoffeeScript CommonJS Functions Don't Work

Reusable CommonJS functions written in CoffeeScript raise exceptions when referenced from map functions.

Consider the following Javascript code:

{
  lib: {
    simple: "exports.callback = function() { return 'Simple' }"
  },
  test: {
    map: "function(doc) { emit(require('views/lib/simple').callback(), doc) }"
  }
}

As expected, "Simple" is emitted for the key of every document.

Now the equivalent CoffeeScript code:

{
  lib: {
    simple: "exports.callback = () -> 'Simple'"
  },
  test: {
    map: "(doc) -> emit(require('views/lib/simple').callback(), doc)"
  }
}

The view returns no results and an error for every document is printed to the log file. For example:

[info] [<0.7270.11>] OS Process #Port<0.96999> Log :: function raised exception (new TypeError("require(\"views/lib/simple\").callback is not a function", "undefined", 3)) with doc._id 8117