Could not scan for classes inside "database/seeds" which does not appear to be a file nor a folde

> 错误长这样

  [RuntimeException]
  Could not scan for classes inside "database/seeds" which 
  does not appear to be a file nor a folder

> 解决办法

- 编写填充器

生成一个填充器，可以通过 Artisan 命令 make:seeder。所有框架生成的填充器都位于 database/seeders 目录。
所有的填充类都位于 database/seeds 目录。填充类的类名完全由你自定义。

php artisan make:seeder UserTableSeeder

- 然后执行

composer update

这时报另一个错了

[RuntimeException]
  Could not scan for classes inside "database/factories" 
  which does not appear to be a file nor a folder

- 继续解决：编写工厂

在app/database目录下新建factories/ModelFactory.php 文件，该文件包含了一个工厂定义(插入以下代码)：

$factory->define(App\User::class, function (Faker\Generator $faker) {
    static $password;

    return [
        'name' => $faker->name,
        'email' => $faker->unique()->safeEmail,
        'password' => $password ?: $password = bcrypt('secret'),
        'remember_token' => str_random(10),
    ];
});

这时再执行

composer require barryvdh/laravel-debugbar

就能看到debugbar安装成功

Using version ^3.1 for barryvdh/laravel-debugbar
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Nothing to install or update
Generating optimized autoload files
> Illuminate\Foundation\ComposerScripts::postAutoloadDump
> @php artisan package:discover
Discovered Package: fideloper/proxy
Discovered Package: laravel/tinker
Discovered Package: barryvdh/laravel-debugbar
Package manifest generated successfully.