Script para automatizar a criação de javascript e css

Gruntfile.js

module.exports = function (grunt) {
    grunt.initConfig({
        pkg: grunt.file.readJSON("package.json"),

        concat: {
            dist: {
                src: [
                    "js/*.js"
                ],
                dest: "../static/js/blog.js"
            }
        },
        uglify: {
            build: {
                src: "../static/js/blog.js",
                dest: "../static/js/blog.min.js"
            }
        },
        imagemin: {
            dynamic: {
                files: [{
                    expand: true,
                    cwd: "img/",
                    src: ["**/*.{png,jpg,gif}"],
                    dest: "../static/img/"
                }]
            }
        },
        sass: {
            dist: {
                options: {
                    style: "compressed"
                },
                files: {
                    "../static/css/blog.css": "sass/blog.scss"
                }
            }
        },
        watch: {
            scripts: {
                files: ["js/*.js"],
                tasks: ["concat", "uglify"],
                options: {
                    spawn: false
                }
            },
            css: {
                files: ["sass/*.scss"],
                tasks: ["sass"],
                options: {
                    spawn: false
                }
            }
        }
    });

    grunt.loadNpmTasks("grunt-contrib-concat");
    grunt.loadNpmTasks("grunt-contrib-uglify");
    grunt.loadNpmTasks("grunt-contrib-imagemin");
    grunt.loadNpmTasks("grunt-contrib-sass");
    grunt.loadNpmTasks("grunt-contrib-watch");

    grunt.registerTask("default", [
        "concat", "uglify", "imagemin", "sass"
    ]);
}

package.json

{
  "name": "assets",
  "version": "1.0.0",
  "devDependencies": {
    "grunt": "^0.4.5",
    "grunt-cli": "^0.1.13",
    "grunt-contrib-concat": "^0.5.1",
    "grunt-contrib-imagemin": "^0.9.4",
    "grunt-contrib-sass": "^0.9.2",
    "grunt-contrib-uglify": "^0.9.1",
    "grunt-contrib-watch": "^0.6.1"
  }
}

watch.sh

#!/bin/bash

node_modules/grunt-cli/bin/grunt watch