Precompile ember handlebars templates with gruntjs

gistfile1.js

/*
Adapted from:  https://gist.github.com/2013669

Usage:
grunt.initConfig({
    ember: {
        all: {
            src: 'templates/*.hjs',
            dest: '../build/templates.compiled.js',
            ember: 'path/to/ember.js',
            handlebars: 'path/to/handlebars.js',
            extension: 'hjs' // the extension of your handlebars templates
        }
    }
});
*/

var compileEmberTemplate = function (ember, handlebars, extension, input) {
    var vm = require('vm');
    var fs = require('fs');
    var path = require('path');

    var jQuery = function() { return jQuery; };
    jQuery.ready = function() { return jQuery; };
    jQuery.inArray = function() { return jQuery; };
    jQuery.jquery = '1.7.1';

    var element = {
        firstChild: function() { return element; },
        innerHTML: function() { return element; }
    };

    var sandbox = {
        document: {
            createRange: false,
            createElement: function() { return element; }
        },
        console: console,
        jQuery: jQuery,
        $: jQuery,
        template: fs.readFileSync(input, 'utf8'),
        templatejs: null
    };
    sandbox.window = sandbox;
    var context = vm.createContext(sandbox);
    vm.runInContext(handlebars, context, 'handlebars.js');
    vm.runInContext(ember, context, 'ember.js');
    vm.runInContext('templatejs = Ember.Handlebars.precompile(template).toString();', context);
    var namedTemplateJs = 'Ember.TEMPLATES["'+path.basename(input, '.'+extension)+'"] = Handlebars.template('+context.templatejs+');';
    return namedTemplateJs;
};
grunt.registerMultiTask('ember', 'Precompile ember templates', function() {
    var fs = require('fs');
    var emberjs = fs.readFileSync(this.data.ember, 'utf8');
    var handlebars = fs.readFileSync(this.data.handlebars, 'utf8');
    var template_files = grunt.file.expand(this.data.src);
    var output = '';
    var ext = this.data.extension || 'handlebars';
    template_files.forEach(function(template) {
        output += compileEmberTemplate(emberjs, handlebars, ext, template);
    });
    grunt.file.write(this.data.dest, output);
});