Test the presence of OptionsResolver when the body_converter validation option is enabled (#1912)

* #1909 test the presence of OptionsResolver when the body_converter validation option is enabled

* use class constant and fix some coding styles

* fix spelling

Author: 2binfree

DependencyInjection/Configuration.php

@@ -16,6 +16,7 @@
 use Symfony\Component\Config\Definition\ConfigurationInterface;
 use Symfony\Component\Config\Definition\Exception\InvalidConfigurationException;
 use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\OptionsResolver\OptionsResolver;
 
 /**
  * This class contains the configuration information for the bundle.
@@ -110,7 +111,17 @@ public function getConfigTreeBuilder()
                 ->arrayNode('body_converter')
                     ->canBeEnabled()
                     ->children()
-                        ->scalarNode('validate')->defaultFalse()->end()
+                        ->scalarNode('validate')
+                            ->defaultFalse()
+                            ->beforeNormalization()
+                                ->ifTrue()
+                                ->then(function () {
+                                    if (!class_exists(OptionsResolver::class)) {
+                                        throw new InvalidConfigurationException("'body_converter.validate: true' requires OptionsResolver component installation ( composer require symfony/options-resolver )");
+                                    }
+                                })
+                            ->end()
+                        ->end()
                         ->scalarNode('validation_errors_argument')->defaultValue('validationErrors')->end()
                     ->end()
                 ->end()