Meteor server unit test - access global object

Question

I have a file in the shared lib directory: lib/functional.js

It attaches an object F to the global scope:

F = (function() {
  return {
    method1: function() {}
  }
})();

In the app this works fine and I can access method1 by F.method1() from everywhere, server and client.

I also have a unit test on the client that passes:

describe('GameController', function () {
  beforeEach(module('blockchess'));

  // Get a new controller and rootscope before each test is executed
  var $controller = {};
  var $scope = {};
  beforeEach(inject(function (_$rootScope_, _$controller_) {
    $controller = _$controller_;
    $scope = _$rootScope_.$new();
  }));

  it('should have a gameId', function () {
    $controller('GameController as ctrl', {
        $scope: $scope
    });
    expect($scope.ctrl.game.gameId).toBe('1');
  });

});

And that controller uses F.method1, and it works fine.

But in the server when I try to make a call in a unit test:

describe('Backfeed', function() {
  var move = {
    _id: '1'
  };

  var john = {
    reputation: 10,
    _id: '1'
  };

  var stars = 5;

  // call protoRate
  Meteor.methodMap.protoRate(john._id, move._id, stars);

  expect(john.reputation).toEqual(9.47368421052632);
})

I get this error:

ReferenceError: F is not defined

/home/adam/apps/blockchess/server/lib/protocol.js:9:14: ReferenceError: F is not defined at Object.protoRate (/home/adam/apps/blockchess/server/lib/protocol.js:9:14) at /home/adam/apps/blockchess/tests/jasmine/server/unit/backfeed/backfeedSpec.js:28:22

In case it helps: I also noticed that if I remove the IIFE wrapping the F function:

F = function() {
  return {
    method1: function() {}
  }
};

I CAN access F from the server unit test, tho it's useless through the app.

Any ideas how to get around this?