 
           # unregister all shells
           unregisterAllShells()
+


    register_fn = -> Registry.registerModule shellModule

    # helper functions
    assertObjectSize = (object, size) => expect(_.keys(object).length).toBe size
    unregisterAllShells = => Registry.modules = {}

    it 'should be a function', ->
      expect(_.isFunction Registry.registerModule).toBe true

          assertObjectSize Registry.modules, 0

      it 'should throw error if properties are of incorrect types', ->
        unregisterAllShells()

        stringProperties = [ 'id', 'title', ]
        _.each stringProperties, (property) ->
          moduleClone = _.clone shellModule
