Make source folder configurable

DependencyInjection/Configuration.php

@@ -22,6 +22,7 @@ final class Configuration implements ConfigurationInterface
         $treeBuilder
             ->root('nelmio_api_doc')
             ->children()
+                ->scalarNode('source_folder')->defaultValue('%kernel.root_dir%/../src')->end()
                 ->arrayNode('routes')
                     ->info('Filter the routes that are documented')
                     ->addDefaultsIfNotSet()

DependencyInjection/NelmioApiDocExtension.php

@@ -41,6 +41,9 @@ final class NelmioApiDocExtension extends Extension
         }
         if (class_exists(Swagger::class)) {
             $loader->load('swagger_php.xml');
+
+            $swaggerPHPDescriber = $container->getDefinition('nelmio_api_doc.describers.swagger_php');
+            $swaggerPHPDescriber->replaceArgument(0, $config['source_folder']);
         }
         if (interface_exists(ParamInterface::class)) {
             $loader->load('fos_rest.xml');

Tests/Functional/TestKernel.php

@@ -62,6 +62,7 @@ class TestKernel extends Kernel
 
         // Filter routes
         $c->loadFromExtension('nelmio_api_doc', [
+            'source_folder' => '%kernel.root_dir%',
             'routes' => [
                 'path_patterns' => ['^/api(?!/admin)'],
             ],