Old snippet I used to play with when I had to route assets manually back then

routes.js

var Path = require('path');
var express = require('express');
var router = express.Router();

function render(_fn, path, param, req, res, next) {
    if (req.params[param]) {
        res[_fn].call(res, Path.join(...[global.appRoot].concat(path(req.params[param]).split("/"))));
    }else {
        next();
    }
}

/**
 * Component's directive's templates
 */
let boundComponentTemplateRouter = render.bind(null, 'render', (templateName) => "public/app/components/templates/" + templateName, 'templateName');
router.get("/components/directives/templates/:templateName", boundComponentTemplateRouter);

/**
 * Shared directive's templates
 */
let boundSharedTemplateRouter = render.bind(null, 'render', (templateName) => "public/app/shared/templates/" + templateName, 'templateName');
router.get("/shared/directives/templates/:templateName", boundSharedTemplateRouter);

/**
 * Component's Views
 */
let boundComponentViewRouter = render.bind(null, 'render', (viewName) => "public/app/components/views/" + viewName, 'viewName');
router.get("/components/views/:viewName", boundComponentViewRouter);

/**
 * Load any node_module
 */
router.get('/node_module/:moduleName/*', function(req, res, next) {
    render('sendFile',(moduleName) => "node_modules/" + moduleName + "/" + req.params['0'], 'moduleName', req, res, next);
});

/**
 * Load any 'angular_module'
 */
router.get('/angular_module/:moduleName/*', function(req, res, next) {
    render('sendFile', (moduleName) => "public/app/assets/vendor/" + moduleName + "/" + req.params['0'], 'moduleName', req, res, next);
});

/* GET users listing. */
router.get('*', function(req, res, next) {
    res.render(Path.join(__dirname, '..', 'public', 'app', 'app'));
});

module.exports = router;