Magento模块中PHP CodeSniffer无法运行的解决求助

问题场景 #

在Magento 2模块项目中安装PHP CodeSniffer，composer.json配置如下：

{
    "name": "test/myModule",
    "description": "testin",
    "type": "magento2-module",
    "version": "1.0.0",
    "require": {
        "php": "^8.1"
    },
    "require-dev": {
        "squizlabs/php_codesniffer": "3.*",
        "magento/magento-coding-standard": "^31.0"
    },
    "autoload": {
      "files": [ "registration.php" ],
      "psr-4": {
        "Test\\Module\\": ""
      }
    }
  }

执行composer update/install成功后，运行命令 vendor/bin/phpcs --standard=Magento2 ./ 时出现致命错误：

PHP Fatal error:  Uncaught Error: Class "Magento\Framework\Component\ComponentRegistrar" not found in /home/cloudpanel/htdocs/magento2.mgt/app/code/Test/Module/registration.php:2
Stack trace:
#0 /home/cloudpanel/htdocs/magento2.mgt/app/code/Test/Module/vendor/composer/autoload_real.php(55): require()
#1 /home/cloudpanel/htdocs/magento2.mgt/app/code/Test/Module/vendor/composer/autoload_real.php(38): composerRequireabd7530303d7978f314768d362cfeb3f()
#2 /home/cloudpanel/htdocs/magento2.mgt/app/code/Test/Module/vendor/autoload.php(25): ComposerAutoloaderInitabd7530303d7978f314768d362cfeb3f::getLoader()
#3 /home/cloudpanel/htdocs/magento2.mgt/app/code/Test/Module/vendor/squizlabs/php_codesniffer/autoload.php(79): include('...')
#4 /home/cloudpanel/htdocs/magento2.mgt/app/code/Test/Module/vendor/squizlabs/php_codesniffer/bin/phpcs(17): PHP_CodeSniffer\Autoload::load()
#5 /home/cloudpanel/htdocs/magento2.mgt/app/code/Test/Module/vendor/bin/phpcs(120): include('...')
#6 {main}
  thrown in /home/cloudpanel/htdocs/magento2.mgt/app/code/Test/Module/registration.php on line 2 

错误原因 #

模块的registration.php被Composer自动加载配置加入了autoload.files列表，运行PHP CodeSniffer时Composer会自动引入该文件。但该文件依赖Magento核心的ComponentRegistrar类，在模块单独目录运行phpcs时无法加载到Magento核心类库，因此触发类不存在的致命错误。

解决方法 #

方法一：调整Composer自动加载配置 #

修改模块的composer.json，将registration.php从自动加载的files中移除，或者添加排除规则让Composer忽略该文件：

"autoload": {
  "psr-4": {
    "Test\\Module\\": ""
  },
  "exclude-from-classmap": [
    "/registration.php"
  ]
}

修改后执行composer dump-autoload更新自动加载规则，再重新运行phpcs命令即可。

方法二：在Magento根目录运行phpcs #

切换到Magento项目根目录，运行phpcs时指定模块路径，此时Magento核心类库已加载，不会出现类缺失问题：

vendor/bin/phpcs --standard=Magento2 app/code/Test/Module/

方法三：修改registration.php增加类存在检查 #

在模块的registration.php中添加类存在判断，避免无法加载Magento核心类时执行注册代码：

<?php
if (class_exists(\Magento\Framework\Component\ComponentRegistrar::class)) {
    \Magento\Framework\Component\ComponentRegistrar::register(
        \Magento\Framework\Component\ComponentRegistrar::MODULE,
        'Test_Module',
        __DIR__
    );
}

修改后直接重新运行phpcs命令即可。

内容的提问来源于stack exchange，提问作者footy