Ruby on Rails asset Pipeline on Sails.js

express.js

// config/express.js

var connectMincer = require('connect-mincer'),
    nib = require('nib'),
    path = require('path'),
    mincer;

// Config for connect-mincer
// See https://github.com/clarkdave/connect-mincer for more details
mincer = new connectMincer({
  root: path.join(__dirname, '../'),
  production: process.env.NODE_ENV === 'production',
  mountPoint: '/assets',
  manifestFile: path.join(__dirname, '../.tmp/public/assets/manifest.json'),
  paths: ['assets/']
});

// Configure Stylus so it can import css files just like .styl files
// Also allows the use of nib (mixin library for stylus)
// Remove is you're not using nib or stylus
mincer.Mincer.StylusEngine.configure(function(style) {
  style.set('include css', true);
  style.use(nib());
});

// Uncomment the lines below to top optionally configure Jade or Coffee 
// See http://nodeca.github.io/mincer for more details

// mincer.Mincer.JadeEngine.configure({});
// mincer.Mincer.CoffeeEngine.configure({});

module.exports = {
 express: {
    customMiddleware: function(app){
      app.use(mincer.assets());

      // Connect-mincer serves our assets in dev
      // We must precompile our assets before starting in production
      if (process.env.NODE_ENV !== 'production') {
        app.use('/assets', mincer.createServer());
      }
    }
  }
};

Gruntfile.js

module.exports = function(grunt) {

  grunt.initConfig({
    shell: {
      precompile: {
        command: 'node precompile.js',
        options: {
          stdout: true,
          failOnError: true
        }
      }
    },

    clean: {
      temp: ['.temp']
    }
  });
  grunt.loadNpmTasks('grunt-shell');
  grunt.loadNpmTasks('grunt-contrib-clean');

  // Run this task before starting in production
  grunt.registerTask('production', [
    'clean',
    'shell:precompile'
  ]);

  // This is Sails's default task when launching the app in production.
  // But Sails runs this task in a different order, and we need to
  // precompile our assets before any middleware is run
  // therefore we run grunt production manually instead
  grunt.registerTask('prod', function() {
    return;
  });

  // Nothing needs to happen in a dev environment :)
  grunt.registerTask('default', function() {
    return;
  });
};

precompile.js

(function() {
  "use strict";
  console.log('Precompiling...');

  var Mincer = require('mincer'),
      CleanCss = require('clean-css'),
      uglify = require('uglify-js'),
      nib = require('nib'),
      mountPoint = '/assets',
      env;

  env = new Mincer.Environment('./');
  Mincer.StylusEngine.configure(function(style) {
    style.set('include css', true)
    style.set('compress', true)
    style.use(nib());
  });

  // Set compressors
  env.jsCompressor = 'uglify';
  env.cssCompressor = function(context, data) {
    var min = '';
    if (data) {
      min = new CleanCss().minify(data)
    }
    return min;
  }

  env.appendPath('assets');

  env.registerHelper('asset_path', function(name, opts) {
    var asset = env.findAsset(name, opts);
    if (!asset){
      throw Error("File [" + name + "] not found");
    }

    return mountPoint + '/' + asset.digestPath;
  });

  var manifest = new Mincer.Manifest(env, '.tmp/public/assets');
  manifest.compile(['*', '*/**'], function(err, data) {
    if(err){
      console.log(err);
      throw err;
    }
    console.info('Finished precompile.');
  });
}());