gruntfile.js

module.exports = function (grunt) {

  grunt.initConfig({
    pkg: grunt.file.readJSON('package.json'),
    concat: {
      dist: {
        src: ['public/js/jquery.min.js', 'public/bootstrap.min.js', 'public/js/app.js'],
        dest: 'public/js/<%= pkg.name %>.add.js'
      }
    },
    uglify: {
      options: {
        banner: '/*! <%= pkg.name %> <%= grunt.template.today("dd-mm-yyyy") %> */\n'
      },
      dist: {
        files: {
          'public/js/<%= pkg.name %>.min.js': ['<%= concat.dist.dest %>']
        }
      }
    },
    sass: {
      dist: {
        files: {
        'public/css/style.css' : 'app/styles/main.scss'
        }
      }
    },
    watch: {
      css: {
        files: '**/*.scss',
        tasks: ['sass']
      }
    }
  });

  // Load Grunt plugins
  grunt.loadNpmTasks('grunt-contrib');
  grunt.loadNpmTasks('grunt-contrib-jshint');
  grunt.loadNpmTasks('grunt-contrib-concat');
  grunt.loadNpmTasks('grunt-contrib-sass');
  grunt.loadNpmTasks('grunt-contrib-watch');

  // Register custom tasks to run from the terminal
  grunt.registerTask('default',['watch']);
};