In my Gruntfile.js I find myself concatenating lots of glob results. Right now it doesn't seem to affect build time but I wondered is there a more performant way of concatenating multiple arrays.
var pattern = 'lib/module/{products,payments,users}';
var code = {
    project: []
        .concat(glob.sync('lib/editor/*.js'))
        .concat(glob.sync('lib/jasmine/helper/*.js'))
        .concat(glob.sync('lib/task/*.js'))
        .concat([
            'Gruntfile.js',
            'models.js',
            'routes.js',
            'server.js'
        ]),
    backend: []
        .concat(glob.sync(pattern + '/{model}/*.js'))
        .concat(glob.sync(pattern + '/route/*.js')),
    frontend: []
        .concat([
            'lib/application.js'
        ])
        .concat(glob.sync(pattern + '/collection/*.js'))
        .concat(glob.sync(pattern + '/editor/*.js'))
        .concat(glob.sync(pattern + '/router/*.js'))
        .concat(glob.sync(pattern + '/view/*.js')),
    spec: []
        .concat(glob.sync(pattern + '/spec/*.js'))
};
