code style fixes

.gitignore

@@ -5,3 +5,4 @@
 /composer.lock
 /docker-compose.yml
 /.phpunit.result.cache
+/.php-cs-fixer.cache

README.md

@@ -101,6 +101,22 @@ $ XDEBUG_MODE=coverage ./vendor/bin/phpunit
 
 HTML coverage path: `build/coverage/index.html`
 
+Code style
+---
+
+To fix code style, run:
+
+```
+~/.composer/vendor/bin/php-cs-fixer fix --config=./phpcs.php --verbose
+```
+
+You have to install [PHP CS Fixer](https://github.com/PHP-CS-Fixer/PHP-CS-Fixer) at first, if you
+don't use build-in Docker image:
+
+```
+composer global require friendsofphp/php-cs-fixer "^3.13.0"
+```
+
 License
 ---
 

phpcs.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Configuration of code style fixer and checker for this library.
+ * This configuration compatible with friendsofphp/php-cs-fixer "^3.13.0".
+ */
+
+use PhpCsFixer\Finder;
+use PhpCsFixer\Config;
+
+$finder = Finder::create()
+    ->in(__DIR__ . '/src')
+    ->in(__DIR__ . '/tests');
+
+$config = new Config();
+$config->setRules([
+    '@PSR12' => true,
+]);
+$config->setFinder($finder);
+
+return $config;

src/ExceptionInterface.php

@@ -7,5 +7,4 @@
  */
 interface ExceptionInterface
 {
-
 }

src/RuntimeException.php

@@ -9,5 +9,4 @@
  */
 class RuntimeException extends BaseRuntimeException implements ExceptionInterface
 {
-
 }

src/XmlConstructor.php

@@ -11,7 +11,7 @@
 
 /**
  * Creating an XML document from an array.
- * 
+ *
  * Usage:
  *
  * $xml = new XmlConstructor();
@@ -132,7 +132,7 @@ public function __construct(array $config = [])
      *         ],
      *     ],
      * ]);
-     * 
+     *
      * @param array $in XML document structure as PHP array.
      * @return static
      * @throws RuntimeException

tests/TestCase.php

@@ -9,5 +9,4 @@
  */
 class TestCase extends BaseTestCase
 {
-
 }

tests/XmlConstructTest.php

@@ -77,7 +77,7 @@ class XmlConstructTest extends TestCase
             ],
         ],
     ];
-    
+
     public function testDefaultDocument1()
     {
         $out1 = <<<XML
@@ -146,7 +146,7 @@ public function testWithStartDocument()
         $out2 = $xml->fromArray($this->in1)->toOutput();
         $this->assertEquals($out1, $out2);
     }
-    
+
     public function testCustomIndentString1()
     {
         $out1 = <<<XML

workenv/Dockerfile

@@ -11,7 +11,8 @@ ARG GITHUB_OAUTH_TOKEN=false
 RUN if [ ${GITHUB_OAUTH_TOKEN} != false ]; then \
   composer config -g github-oauth.github.com ${GITHUB_OAUTH_TOKEN} \
 ;fi
-
 RUN export COMPOSER_DISABLE_XDEBUG_WARN=1
 
+RUN composer global require friendsofphp/php-cs-fixer "^3.13.0"
+
 CMD ["php", "-a"]