global-to-module.js

var underscore = angular.module('underscore', []);
underscore.factory('_', function() {
    return window._; //Underscore must already be loaded on the page
});

var app = angular.module('app', ['underscore']);

app.controller('MainCtrl', ['$scope', '_', function($scope, _) {
    init = function() {
        _.keys($scope);
    }

    init();
}]);