package.json

{
  "private": true,
  "scripts": {
    "dev": "npm run development",
    "development": "cross-env NODE_ENV=development node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
    "watch": "cross-env NODE_ENV=development node_modules/webpack/bin/webpack.js --watch --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
    "watch-poll": "npm run watch -- --watch-poll",
    "hot": "cross-env NODE_ENV=development node_modules/webpack-dev-server/bin/webpack-dev-server.js --inline --hot --config=node_modules/laravel-mix/setup/webpack.config.js",
    "prod": "npm run production",
    "production": "cross-env NODE_ENV=production node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js"
  },
  "devDependencies": {
    "axios": "^0.16.2",
    "bootstrap-sass": "^3.3.7",
    "cross-env": "^5.0.1",
    "gulp-notify": "^3.0.0",
    "is": "^3.2.1",
    "jquery": "^3.1.1",
    "laravel-elixir": "^5.0.0",
    "laravel-mix": "^1.0",
    "lodash": "^4.17.4",
    "node.extend": "^2.0.0",
    "vue": "^2.1.10"
  }
}

gulpfile.js

var elixir = require('laravel-elixir');

elixir(function (mix) {
    mix.sass('app.scss');

    mix.browserSync({
        files: ['app/**/*', 'public/**/*', 'resources/views/**/*'],
        port: 5000,
        proxy: 'localhost:8000'
    });
});

Execute “gulp watch” will open a new window, this window will be watching file changes

Reference:

1. https://laravel.tw/docs/5.0/elixir
2. http://oomusou.io/laravel/elixir/elixir-browsersync/