gruntfile.js

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

    sass: {
      dist: {
        files: {
          'css/main.css' : 'sass/main.scss'
        }
      }
    },

    autoprefixer: {
        options: {
          // autoprefixed options
            browsers: ['last 5 versions', 'Safari >= 5.0']
        },
        dist: {
          //  targeted files
            files: {
                'css/main.css': 'css/main.css'
            }
        }
      },

      watch: {
        css: {
        files: ['sass/**/*.scss'],
        tasks: ['sass'],
        options: {
          livereload: true,
        },
        },
      },



    uglify: {
      options: {
        manage: false,
        preserveComments: 'all'
      },
      my_target:{
        files:[{
          expand: true,
          cwd: 'js/',
          src: '**/*.js',
          dest: 'js',
        }]
      }
    },

    cssmin:{
      my_target: {
        files:[{
          expand: true,
          cwd: 'css/',
          src: ['*.css','!*.min.css'],
          dest: 'css/',
          ext: '.min.css'
        }]
      }
    }
  });

    grunt.loadNpmTasks('grunt-contrib-sass');
    grunt.loadNpmTasks('grunt-contrib-watch');
    grunt.loadNpmTasks('grunt-contrib-cssmin');
    grunt.loadNpmTasks('grunt-contrib-uglify');
    grunt.loadNpmTasks('grunt-autoprefixer');
    // grunt.loadNpmTasks('grunt-contrib-concat');

    grunt.registerTask('default', ['sass','autoprefixer','uglify', 'cssmin']);


};