Configuração do Grunt

Gruntfile.js

var mozjpeg = require('imagemin-mozjpeg');
module.exports = function (grunt) {
  var json = {
    js: {
      src: [
        'src/js/jquery-1.11.2.js',
        'src/js/SmoothScroll.js',
        'src/js/main.js',
      ],
      dest: 'assets/js/main.js',
      min: 'assets/js/main.min.js'
    },
    styl: {
      src: [
        'src/styl/main.styl'
      ],
      dest: 'assets/css/main.css',
      min: 'assets/css/main.min.css'
    }
  };
  grunt.initConfig({
    pkg: grunt.file.readJSON('package.json'),
    concat: {
      options: {
        separator: ';',
        sourceMap: true,
      },
      dist: {
        src: json.js.src,
        dest: json.js.dest
      },
    },
    uglify: {
      dist: {
        options: {
          // sourceMap: true,
          compress: {
            drop_console: true
          }
        },
        src: json.js.src,
        dest: json.js.min
      }
    },
    stylus: {
      dev: {
        options: {
          compress: false,
          sourcemap: {
            inline: true
          }
        },
        src: json.styl.src,
        dest: json.styl.dest
      },
      prod: {
        src: json.styl.src,
        dest: json.styl.min
      }
    },
    imagemin: { // Task
      dynamic: { // Another target
        files: [{
          expand: true, // Enable dynamic expansion
          cwd: 'src/img/', // Src matches are relative to this path
          src: ['*.{png,jpg,gif}'], // Actual patterns to match
          dest: 'assets/img/' // Destination path prefix
        }]
      }
    },
    sprite: {
      spritesheet: {
        src: "src/img/sprites/*.png",
        dest: "assets/img/sprite.png",
        destCss: 'src/styl/sprites.styl',
        cssTemplate: 'src/styl/sprites.styl.tpl',
        padding: 10,
        algorithm: "binary-tree",
        imgPath: "../img/sprite.png"
      }
    },

    // gzip assets 1-to-1 for production
    compress: {
      main: {
        options: {
          archive: 'gol.zip'
        },
        expand: true,
        cwd: '.',
        src: ['assets/**/*', 'index.html'],
        dest: '.'
      }
    },

    watch: {
      configFiles: {
        files: ['Gruntfile.js'],
        options: {
          reload: true
        }
      },
      js: {
        files: [json.js.src],
        tasks: ['js'],
        options: {
          spawn: false,
        },
      },
      css: {
        files: ['src/styl/**/*.styl'],
        tasks: ['css'],
        options: {
          spawn: false,
        },
      },
      img: {
        files: ['src/img/*.{png,jpg,gif}'],
        tasks: ['imagemin'],
        options: {
          spawn: false,
        },
      },
      sprite: {
        files: ['src/img/sprites/*.{png,jpg}'],
        tasks: ['s'],
        options: {
          spawn: true,
        },
      },
    }
  });

  grunt.loadNpmTasks('grunt-contrib-concat');
  grunt.loadNpmTasks('grunt-contrib-uglify');
  grunt.loadNpmTasks('grunt-contrib-stylus');
  grunt.loadNpmTasks('grunt-contrib-watch');
  grunt.loadNpmTasks('grunt-contrib-imagemin');
  grunt.loadNpmTasks('grunt-spritesmith');
  grunt.loadNpmTasks('grunt-contrib-compress');

  grunt.registerTask('zip', ['compress']);
  grunt.registerTask('js', ['concat', 'uglify']);
  grunt.registerTask('css', ['stylus']);
  grunt.registerTask('s', ['sprite', 'css']);
  grunt.registerTask('w', ['sprite', 'imagemin', 'js', 'css', 'watch']);
  grunt.registerTask('default', ['js', 'css']);

};