add --level shortcut option

bin/rector.php

@@ -1,5 +1,6 @@
 <?php declare(strict_types=1);
 
+use Rector\Configuration\RectorConfigFilePathHelper;
 use Rector\Console\Application;
 use Rector\DependencyInjection\ContainerFactory;
 use Symfony\Component\Console\Input\ArgvInput;
@@ -13,13 +14,17 @@ gc_disable();
 require_once __DIR__ . '/bootstrap.php';
 
 try {
-    // 1. Detect configuration
-    ConfigFilePathHelper::detectFromInput('rector', new ArgvInput);
+    // 1. Detect configuration from --level
+    $configFile = RectorConfigFilePathHelper::resolveLevel(new ArgvInput);
+
+    // 2. Or from --config
+    if ($configFile === null) {
+        ConfigFilePathHelper::detectFromInput('rector', new ArgvInput);
+        $configFile = ConfigFilePathHelper::provide('rector', 'rector.yml');
+    }
 
     // 2. Build DI container
     $containerFactory = new ContainerFactory;
-    $configFile = ConfigFilePathHelper::provide('rector', 'rector.yml');
-
     if ($configFile) {
         $container = $containerFactory->createWithConfig($configFile);
     } else {

src/Configuration/RectorConfigFilePathHelper.php

@@ -0,0 +1,49 @@
+<?php declare(strict_types=1);
+
+namespace Rector\Configuration;
+
+use SplFileInfo;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Finder\Finder;
+
+final class RectorConfigFilePathHelper
+{
+    /**
+     * @var string
+     */
+    private const LEVEL_OPTION_NAME = '--level';
+
+    /**
+     * @var string
+     */
+    private static $levelDirectory = __DIR__ . '/../config/level';
+
+    public static function resolveLevel(InputInterface $input): ?string
+    {
+        if (! $input->hasParameterOption(self::LEVEL_OPTION_NAME)) {
+            return null;
+        }
+
+        $levelConfigName = $input->getParameterOption(self::LEVEL_OPTION_NAME);
+
+        $finder = Finder::create()
+            ->files()
+            ->name($levelConfigName . '.yml')
+            ->in(self::$levelDirectory);
+
+        $firstFile = self::getFirstFileFromFinder($finder);
+        if (! $firstFile) {
+            return null;
+        }
+
+        return $firstFile->getRealPath();
+    }
+
+    private static function getFirstFileFromFinder(Finder $finder): ?SplFileInfo
+    {
+        $iterator = $finder->getIterator();
+        $iterator->rewind();
+
+        return $iterator->current();
+    }
+}

src/Console/Application.php

@@ -20,8 +20,8 @@ final class Application extends SymfonyApplication
     }
 
     /**
-     * This method override adds option to
-     * load custom config via --config in any command.
+     * This method override adds option to load custom config via --config in any command.
+     * And --level option as well.
      */
     protected function getDefaultInputDefinition(): InputDefinition
     {
@@ -34,6 +34,12 @@ final class Application extends SymfonyApplication
                 'Path to config file.',
                 getcwd() . '/rector.yml'
             ),
+            new InputOption(
+                '--level',
+                null,
+                InputOption::VALUE_REQUIRED,
+                'Finds config by shortcut name.'
+            ),
             new InputOption('--help', '-h', InputOption::VALUE_NONE, 'Display this help message'),
             new InputOption('--ansi', '', InputOption::VALUE_NONE, 'Force ANSI output'),
             new InputOption('--no-ansi', '', InputOption::VALUE_NONE, 'Disable ANSI output'),