diff --git a/.gitattributes b/.gitattributes
index 9fe8f71..ed85a9d 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,5 +1,4 @@
-/src/Builder/ export-ignore
-/tests/ export-ignore
+/dev/ export-ignore
 /.* export-ignore
 /phpunit.xml export-ignore
 
diff --git a/.php-cs-fixer.php b/.php-cs-fixer.php
index c80e6f0..cb3b194 100644
--- a/.php-cs-fixer.php
+++ b/.php-cs-fixer.php
@@ -9,12 +9,14 @@
  * the LICENSE file that was distributed with this source code.
  */
 
+require_once __DIR__ . '/vendor/autoload.php';
+
 return PhpCsFixerConfig\Factory::createForLibrary('kubawerlos/php-cs-fixer-config', 'Kuba Werłos', 2020)
     ->setUsingCache(false)
     ->setFinder(
         PhpCsFixer\Finder::create()
             ->files()
+            ->in(__DIR__ . '/dev')
             ->in(__DIR__ . '/src')
-            ->in(__DIR__ . '/tests')
             ->append([__FILE__]),
     );
diff --git a/composer.json b/composer.json
index ff3e39b..c66314c 100644
--- a/composer.json
+++ b/composer.json
@@ -10,11 +10,11 @@
     ],
     "require": {
         "php": "^8.0",
-        "friendsofphp/php-cs-fixer": "^3.6.0",
-        "kubawerlos/php-cs-fixer-custom-fixers": "^3.8.0"
+        "kubawerlos/php-cs-fixer-custom-fixers": "^3.10.0",
+        "php-cs-fixer/shim": "^3.7.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.5.10"
+        "phpunit/phpunit": "^9.5.19"
     },
     "autoload": {
         "psr-4": {
@@ -23,12 +23,12 @@
     },
     "autoload-dev": {
         "psr-4": {
-            "Tests\\": "./tests"
+            "Dev\\": "./dev"
         }
     },
     "scripts": {
         "fix": [
-            "@php ./src/Builder/build.php",
+            "@php ./dev/build.php",
             "php-cs-fixer fix --quiet"
         ],
         "verify": [
diff --git a/src/Builder/Builder.php b/dev/Builder/Builder.php
similarity index 89%
rename from src/Builder/Builder.php
rename to dev/Builder/Builder.php
index 208ea44..66e002f 100644
--- a/src/Builder/Builder.php
+++ b/dev/Builder/Builder.php
@@ -9,10 +9,10 @@
  * the LICENSE file that was distributed with this source code.
  */
 
-namespace PhpCsFixerConfig\Builder;
+namespace Dev\Builder;
 
-use PhpCsFixerConfig\Builder\Modifier\LibraryRulesModifier;
-use PhpCsFixerConfig\Builder\Modifier\ProjectRulesModifier;
+use Dev\Builder\Modifier\LibraryRulesModifier;
+use Dev\Builder\Modifier\ProjectRulesModifier;
 
 /**
  * @internal
@@ -47,7 +47,7 @@ private function dumpClass(string $name, Rules $rules): void
         $array = \preg_replace('/\d+\s*=>/', '', $array);
         $array = \str_replace("'__HEADER_PLACEHOLDER__'", '$this->header', $array);
 
-        $path = __DIR__ . '/../Rules/' . $name . '.php';
+        $path = __DIR__ . '/../../src/Rules/' . $name . '.php';
 
         $content = \file_get_contents($path);
 
diff --git a/src/Builder/Modifier/LibraryRulesModifier.php b/dev/Builder/Modifier/LibraryRulesModifier.php
similarity index 96%
rename from src/Builder/Modifier/LibraryRulesModifier.php
rename to dev/Builder/Modifier/LibraryRulesModifier.php
index 080ae05..d3c92ac 100644
--- a/src/Builder/Modifier/LibraryRulesModifier.php
+++ b/dev/Builder/Modifier/LibraryRulesModifier.php
@@ -9,7 +9,7 @@
  * the LICENSE file that was distributed with this source code.
  */
 
-namespace PhpCsFixerConfig\Builder\Modifier;
+namespace Dev\Builder\Modifier;
 
 use PhpCsFixerCustomFixers\Fixer\NoNullableBooleanTypeFixer;
 use PhpCsFixerCustomFixers\Fixer\PhpdocOnlyAllowedAnnotationsFixer;
diff --git a/src/Builder/Modifier/NonDefaultConfiguration.php b/dev/Builder/Modifier/NonDefaultConfiguration.php
similarity index 97%
rename from src/Builder/Modifier/NonDefaultConfiguration.php
rename to dev/Builder/Modifier/NonDefaultConfiguration.php
index 5645a72..edf9ee0 100644
--- a/src/Builder/Modifier/NonDefaultConfiguration.php
+++ b/dev/Builder/Modifier/NonDefaultConfiguration.php
@@ -9,7 +9,7 @@
  * the LICENSE file that was distributed with this source code.
  */
 
-namespace PhpCsFixerConfig\Builder\Modifier;
+namespace Dev\Builder\Modifier;
 
 use PhpCsFixer\Fixer\Whitespace\NoExtraBlankLinesFixer;
 
diff --git a/src/Builder/Modifier/ProjectRulesModifier.php b/dev/Builder/Modifier/ProjectRulesModifier.php
similarity index 94%
rename from src/Builder/Modifier/ProjectRulesModifier.php
rename to dev/Builder/Modifier/ProjectRulesModifier.php
index 23b6d95..ec281ce 100644
--- a/src/Builder/Modifier/ProjectRulesModifier.php
+++ b/dev/Builder/Modifier/ProjectRulesModifier.php
@@ -9,7 +9,7 @@
  * the LICENSE file that was distributed with this source code.
  */
 
-namespace PhpCsFixerConfig\Builder\Modifier;
+namespace Dev\Builder\Modifier;
 
 use PhpCsFixerCustomFixers\Fixer\PhpdocOnlyAllowedAnnotationsFixer;
 
diff --git a/src/Builder/Modifier/UnwantedRulesFilter.php b/dev/Builder/Modifier/UnwantedRulesFilter.php
similarity index 84%
rename from src/Builder/Modifier/UnwantedRulesFilter.php
rename to dev/Builder/Modifier/UnwantedRulesFilter.php
index 8793de4..18cf448 100644
--- a/src/Builder/Modifier/UnwantedRulesFilter.php
+++ b/dev/Builder/Modifier/UnwantedRulesFilter.php
@@ -9,7 +9,7 @@
  * the LICENSE file that was distributed with this source code.
  */
 
-namespace PhpCsFixerConfig\Builder\Modifier;
+namespace Dev\Builder\Modifier;
 
 /**
  * @internal
@@ -25,11 +25,13 @@ final class UnwantedRulesFilter
         'group_import',
         'linebreak_after_opening_tag',
         'no_blank_lines_before_namespace',
+        'no_trailing_comma_in_singleline_function_call', // NoTrailingCommaInSinglelineFixer used
         'not_operator_with_space',
         'not_operator_with_successor_space',
         'php_unit_size_class',
         'phpdoc_summary',
         'phpdoc_to_property_type',
+        'single_line_comment_spacing', // CommentSurroundedBySpacesFixer used
     ];
 
     /**
diff --git a/src/Builder/Rules.php b/dev/Builder/Rules.php
similarity index 80%
rename from src/Builder/Rules.php
rename to dev/Builder/Rules.php
index 41828f6..9413bc8 100644
--- a/src/Builder/Rules.php
+++ b/dev/Builder/Rules.php
@@ -9,10 +9,13 @@
  * the LICENSE file that was distributed with this source code.
  */
 
-namespace PhpCsFixerConfig\Builder;
+namespace Dev\Builder;
 
+use Dev\Builder\Modifier\NonDefaultConfiguration;
+use Dev\Builder\Modifier\UnwantedRulesFilter;
 use PhpCsFixer\Fixer\DeprecatedFixerInterface;
 use PhpCsFixer\FixerFactory;
+use PhpCsFixerCustomFixers\Fixers;
 
 /**
  * @internal
@@ -36,15 +39,15 @@ public function __construct()
 
         \ksort($this->rules);
 
-        foreach (new \PhpCsFixerCustomFixers\Fixers() as $fixer) {
+        foreach (new Fixers() as $fixer) {
             if ($fixer instanceof DeprecatedFixerInterface) {
                 continue;
             }
             $this->rules[$fixer->getName()] = true;
         }
 
-        $this->apply(new Modifier\NonDefaultConfiguration());
-        $this->apply(new Modifier\UnwantedRulesFilter());
+        $this->apply(new NonDefaultConfiguration());
+        $this->apply(new UnwantedRulesFilter());
     }
 
     public function apply(callable $closure): void
diff --git a/tests/AutoReview/SrcCodeTest.php b/dev/Test/AutoReview/SrcCodeTest.php
similarity index 94%
rename from tests/AutoReview/SrcCodeTest.php
rename to dev/Test/AutoReview/SrcCodeTest.php
index 0c072c4..d1dab15 100644
--- a/tests/AutoReview/SrcCodeTest.php
+++ b/dev/Test/AutoReview/SrcCodeTest.php
@@ -9,7 +9,7 @@
  * the LICENSE file that was distributed with this source code.
  */
 
-namespace Tests\AutoReview;
+namespace Dev\Test\AutoReview;
 
 use PhpCsFixerConfig\Factory;
 use PHPUnit\Framework\TestCase;
@@ -27,7 +27,7 @@ public function testOnlyFactoryClassIsPublic(): void
     {
         $finder = Finder::create()
             ->files()
-            ->in(__DIR__ . '/../../src')
+            ->in(__DIR__ . '/../../../src')
             ->notName('build.php');
 
         /** @var SplFileInfo $file */
diff --git a/tests/Builder/Modifier/NonDefaultConfigurationTest.php b/dev/Test/Builder/Modifier/NonDefaultConfigurationTest.php
similarity index 94%
rename from tests/Builder/Modifier/NonDefaultConfigurationTest.php
rename to dev/Test/Builder/Modifier/NonDefaultConfigurationTest.php
index db103d3..eb030d4 100644
--- a/tests/Builder/Modifier/NonDefaultConfigurationTest.php
+++ b/dev/Test/Builder/Modifier/NonDefaultConfigurationTest.php
@@ -9,19 +9,19 @@
  * the LICENSE file that was distributed with this source code.
  */
 
-namespace Tests\Builder\Modifier;
+namespace Dev\Test\Builder\Modifier;
 
+use Dev\Builder\Modifier\NonDefaultConfiguration;
 use PhpCsFixer\Fixer\DeprecatedFixerInterface;
 use PhpCsFixer\Fixer\FixerInterface;
 use PhpCsFixer\FixerConfiguration\DeprecatedFixerOptionInterface;
 use PhpCsFixer\FixerFactory;
 use PhpCsFixer\RuleSet\RuleSet;
-use PhpCsFixerConfig\Builder\Modifier\NonDefaultConfiguration;
 use PhpCsFixerCustomFixers\Fixers;
 use PHPUnit\Framework\TestCase;
 
 /**
- * @covers \PhpCsFixerConfig\Builder\Modifier\NonDefaultConfiguration
+ * @covers \Dev\Builder\Modifier\NonDefaultConfiguration
  *
  * @internal
  */
diff --git a/tests/Builder/Modifier/UnwantedRulesFilterTest.php b/dev/Test/Builder/Modifier/UnwantedRulesFilterTest.php
similarity index 91%
rename from tests/Builder/Modifier/UnwantedRulesFilterTest.php
rename to dev/Test/Builder/Modifier/UnwantedRulesFilterTest.php
index 4e8284e..cbf386d 100644
--- a/tests/Builder/Modifier/UnwantedRulesFilterTest.php
+++ b/dev/Test/Builder/Modifier/UnwantedRulesFilterTest.php
@@ -9,18 +9,18 @@
  * the LICENSE file that was distributed with this source code.
  */
 
-namespace Tests\Builder\Modifier;
+namespace Dev\Test\Builder\Modifier;
 
+use Dev\Builder\Modifier\UnwantedRulesFilter;
 use PhpCsFixer\Fixer\DeprecatedFixerInterface;
 use PhpCsFixer\Fixer\FixerInterface;
 use PhpCsFixer\FixerFactory;
 use PhpCsFixer\RuleSet\RuleSet;
-use PhpCsFixerConfig\Builder\Modifier\UnwantedRulesFilter;
 use PhpCsFixerCustomFixers\Fixers;
 use PHPUnit\Framework\TestCase;
 
 /**
- * @covers \PhpCsFixerConfig\Builder\Modifier\UnwantedRulesFilter
+ * @covers \Dev\Builder\Modifier\UnwantedRulesFilter
  *
  * @internal
  */
diff --git a/tests/BuilderTest.php b/dev/Test/BuilderTest.php
similarity index 79%
rename from tests/BuilderTest.php
rename to dev/Test/BuilderTest.php
index a1805e1..a082160 100644
--- a/tests/BuilderTest.php
+++ b/dev/Test/BuilderTest.php
@@ -9,15 +9,15 @@
  * the LICENSE file that was distributed with this source code.
  */
 
-namespace Tests;
+namespace Dev;
 
-use PhpCsFixerConfig\Builder\Modifier\NonDefaultConfiguration;
-use PhpCsFixerConfig\Builder\Modifier\UnwantedRulesFilter;
+use Dev\Builder\Modifier\NonDefaultConfiguration;
+use Dev\Builder\Modifier\UnwantedRulesFilter;
 use PHPUnit\Framework\TestCase;
 
 /**
- * @covers \PhpCsFixerConfig\Builder\Modifier\NonDefaultConfiguration
- * @covers \PhpCsFixerConfig\Builder\Modifier\UnwantedRulesFilter
+ * @covers \Dev\Builder\Modifier\NonDefaultConfiguration
+ * @covers \Dev\Builder\Modifier\UnwantedRulesFilter
  *
  * @internal
  */
diff --git a/tests/FactoryTest.php b/dev/Test/FactoryTest.php
similarity index 97%
rename from tests/FactoryTest.php
rename to dev/Test/FactoryTest.php
index 2c3eba6..51c997f 100644
--- a/tests/FactoryTest.php
+++ b/dev/Test/FactoryTest.php
@@ -9,7 +9,7 @@
  * the LICENSE file that was distributed with this source code.
  */
 
-namespace Tests;
+namespace Dev;
 
 use PhpCsFixer\Config;
 use PhpCsFixerConfig\Factory;
diff --git a/tests/Rules/LibraryRulesTest.php b/dev/Test/Rules/LibraryRulesTest.php
similarity index 93%
rename from tests/Rules/LibraryRulesTest.php
rename to dev/Test/Rules/LibraryRulesTest.php
index ed3b678..50f7053 100644
--- a/tests/Rules/LibraryRulesTest.php
+++ b/dev/Test/Rules/LibraryRulesTest.php
@@ -9,12 +9,12 @@
  * the LICENSE file that was distributed with this source code.
  */
 
-namespace Tests\Rules;
+namespace Dev\Test\Rules;
 
+use Dev\Builder\Modifier\LibraryRulesModifier;
+use Dev\Builder\Rules;
 use PhpCsFixer\FixerFactory;
 use PhpCsFixer\RuleSet\RuleSet;
-use PhpCsFixerConfig\Builder\Modifier\LibraryRulesModifier;
-use PhpCsFixerConfig\Builder\Rules;
 use PhpCsFixerConfig\Rules\LibraryRules;
 use PhpCsFixerCustomFixers\Fixers;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Rules/ProjectRulesTest.php b/dev/Test/Rules/ProjectRulesTest.php
similarity index 91%
rename from tests/Rules/ProjectRulesTest.php
rename to dev/Test/Rules/ProjectRulesTest.php
index a8b3b57..e670618 100644
--- a/tests/Rules/ProjectRulesTest.php
+++ b/dev/Test/Rules/ProjectRulesTest.php
@@ -9,12 +9,12 @@
  * the LICENSE file that was distributed with this source code.
  */
 
-namespace Tests\Rules;
+namespace Dev\Test\Rules;
 
+use Dev\Builder\Modifier\ProjectRulesModifier;
+use Dev\Builder\Rules;
 use PhpCsFixer\FixerFactory;
 use PhpCsFixer\RuleSet\RuleSet;
-use PhpCsFixerConfig\Builder\Modifier\ProjectRulesModifier;
-use PhpCsFixerConfig\Builder\Rules;
 use PhpCsFixerConfig\Rules\ProjectRules;
 use PhpCsFixerCustomFixers\Fixers;
 use PHPUnit\Framework\TestCase;
diff --git a/dev/autoload.php b/dev/autoload.php
new file mode 100644
index 0000000..742464a
--- /dev/null
+++ b/dev/autoload.php
@@ -0,0 +1,19 @@
+<?php declare(strict_types=1);
+
+/*
+ * This file is part of kubawerlos/php-cs-fixer-config.
+ *
+ * (c) 2020 Kuba Werłos
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+$phar = __DIR__ . '/../vendor/php-cs-fixer/shim/php-cs-fixer';
+
+$pharLoaded = Phar::loadPhar($phar, 'php-cs-fixer.phar');
+if (!$pharLoaded) {
+    exit(sprintf('Phar "%s" not loaded!' . PHP_EOL, $phar));
+}
+
+require_once 'phar://php-cs-fixer.phar/vendor/autoload.php';
diff --git a/dev/build.php b/dev/build.php
new file mode 100644
index 0000000..ba3b9fa
--- /dev/null
+++ b/dev/build.php
@@ -0,0 +1,18 @@
+<?php declare(strict_types=1);
+
+/*
+ * This file is part of kubawerlos/php-cs-fixer-config.
+ *
+ * (c) 2020 Kuba Werłos
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+require __DIR__ . '/../vendor/autoload.php';
+require __DIR__ . '/autoload.php';
+
+$builder = new Dev\Builder\Builder();
+$builder->build();
+
+exec('php ' . __DIR__ . '/../vendor/bin/php-cs-fixer fix');
diff --git a/phpunit.xml b/phpunit.xml
index 002ee73..9817892 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -2,6 +2,7 @@
 
 <phpunit xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'
          xsi:noNamespaceSchemaLocation='./vendor/phpunit/phpunit/phpunit.xsd'
+         bootstrap='dev/autoload.php'
          cacheResult='false'
          colors='true'
          forceCoversAnnotation='true'
@@ -16,7 +17,7 @@
 
     <testsuites>
         <testsuite name='all'>
-            <directory>./tests/</directory>
+            <directory>./dev/Test/</directory>
         </testsuite>
     </testsuites>
 
@@ -24,9 +25,6 @@
         <include>
             <directory>./src/</directory>
         </include>
-        <exclude>
-            <directory>./src/Builder/</directory>
-        </exclude>
         <report>
             <text outputFile='php://stdout' showOnlySummary='true' />
         </report>
diff --git a/src/Builder/build.php b/src/Builder/build.php
deleted file mode 100644
index 07033e4..0000000
--- a/src/Builder/build.php
+++ /dev/null
@@ -1,22 +0,0 @@
-<?php declare(strict_types=1);
-
-/*
- * This file is part of kubawerlos/php-cs-fixer-config.
- *
- * (c) 2020 Kuba Werłos
- *
- * For the full copyright and license information, please view
- * the LICENSE file that was distributed with this source code.
- */
-
-require __DIR__ . '/../../vendor/autoload.php';
-
-$builder = new PhpCsFixerConfig\Builder\Builder();
-$builder->build();
-
-$process = Symfony\Component\Process\Process::fromShellCommandline('php ' . __DIR__ . '/../../vendor/bin/php-cs-fixer fix');
-$exitCode = $process->run();
-
-if ($exitCode > 0) {
-    throw new RuntimeException($process->getErrorOutput());
-}
diff --git a/src/Rules/LibraryRules.php b/src/Rules/LibraryRules.php
index 4e1d489..ef9812d 100644
--- a/src/Rules/LibraryRules.php
+++ b/src/Rules/LibraryRules.php
@@ -211,6 +211,7 @@ public function getRules(): array
             ],
             'no_trailing_comma_in_list_call' => true,
             'no_trailing_comma_in_singleline_array' => true,
+            'no_trailing_comma_in_singleline_function_call' => false,
             'no_trailing_whitespace' => true,
             'no_trailing_whitespace_in_comment' => true,
             'no_trailing_whitespace_in_string' => true,
@@ -310,6 +311,7 @@ public function getRules(): array
             'single_class_element_per_statement' => true,
             'single_import_per_statement' => true,
             'single_line_after_imports' => true,
+            'single_line_comment_spacing' => false,
             'single_line_comment_style' => true,
             'single_line_throw' => true,
             'single_quote' => true,
@@ -403,6 +405,7 @@ public function getRules(): array
             Fixer\PhpdocParamTypeFixer::name() => true,
             Fixer\PhpdocSelfAccessorFixer::name() => true,
             Fixer\PhpdocSingleLineVarFixer::name() => true,
+            Fixer\PhpdocTypesCommaSpacesFixer::name() => true,
             Fixer\PhpdocTypesTrimFixer::name() => true,
             Fixer\PhpdocVarAnnotationToAssertFixer::name() => true,
             Fixer\PromotedConstructorPropertyFixer::name() => true,
diff --git a/src/Rules/ProjectRules.php b/src/Rules/ProjectRules.php
index f925e01..d3f677d 100644
--- a/src/Rules/ProjectRules.php
+++ b/src/Rules/ProjectRules.php
@@ -189,6 +189,7 @@ public function getRules(): array
             ],
             'no_trailing_comma_in_list_call' => true,
             'no_trailing_comma_in_singleline_array' => true,
+            'no_trailing_comma_in_singleline_function_call' => false,
             'no_trailing_whitespace' => true,
             'no_trailing_whitespace_in_comment' => true,
             'no_trailing_whitespace_in_string' => true,
@@ -288,6 +289,7 @@ public function getRules(): array
             'single_class_element_per_statement' => true,
             'single_import_per_statement' => true,
             'single_line_after_imports' => true,
+            'single_line_comment_spacing' => false,
             'single_line_comment_style' => true,
             'single_line_throw' => true,
             'single_quote' => true,
@@ -365,6 +367,7 @@ public function getRules(): array
             Fixer\PhpdocParamTypeFixer::name() => true,
             Fixer\PhpdocSelfAccessorFixer::name() => true,
             Fixer\PhpdocSingleLineVarFixer::name() => true,
+            Fixer\PhpdocTypesCommaSpacesFixer::name() => true,
             Fixer\PhpdocTypesTrimFixer::name() => true,
             Fixer\PhpdocVarAnnotationToAssertFixer::name() => true,
             Fixer\PromotedConstructorPropertyFixer::name() => true,