Build static assets with grunt.

Gruntfile.js

module.exports = function(grunt) {

  grunt.initConfig({

    uglify: {
      js: {
        files: {
          // These are all of js files we want minified and combined.
          'pub/main.js': ['src/js/main.js'],
          'pub/eggs.js': ['src/js/eggs.js', 'src/js/milk.js'],
          'pub/pancake.js': ['src/js/milk.js', 'src/js/flour.js', 'src/js/eggs.js']
       }
     }
    },

    sass: {
      css: {
        options: {
          sourcemap: 'none',
          style: 'compressed',
          noCache: true,
          update: true
        },
        files: {
          // These are all of the css files we want compiled.
          // Note that imports within the files are handled properly
          // and we don't need to include them here.
          'pub/blueberry.css': 'src/css/blueberry.scss',
          'pub/yogurt.css': 'src/css/yogurt.scss'
        }
      }
    },

    // `grunt copy` syncs i/ and lib/.
    copy: {
      all: {
        cwd: 'src',
        // These are the directories to be copied as-is.
        // These must also be specified below in the watch block.
        src: ['i/**', 'lib/**'],
        dest: 'pub',
        expand: true
      },
    },

    // `grunt clean` is equivalent to `rm -rf pub`.
    clean: ['pub'],

    // `grunt watch` monitors the source directories and updates pub/ as needed.
    watch: {
      js: {
        files: ['src/js/**'],
        tasks: ['uglify']
      },
      css: {
        files: ['src/css/**'],
        tasks: ['sass']
      },
      copy: {
        files: ['src/i/**', 'src/lib/**'],
        tasks: ['copy']
      }
    }

  });

  // These should match what's in package.json.
  grunt.loadNpmTasks('grunt-contrib-uglify');
  grunt.loadNpmTasks('grunt-contrib-sass');
  grunt.loadNpmTasks('grunt-contrib-copy');
  grunt.loadNpmTasks('grunt-contrib-clean');
  grunt.loadNpmTasks('grunt-contrib-watch');

  // `grunt build` updates all of the js and css.
  grunt.registerTask('build', ['uglify', 'sass']);

  // `grunt all`  does a complete rebuild and is the default action.
  grunt.registerTask('all', ['clean', 'build', 'copy']);
  grunt.registerTask('default', ['all']);
};