diff --git a/.gitignore b/.gitignore
index 19982ea..209d67e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,9 @@
 composer.lock
-vendor
\ No newline at end of file
+vendor
+.idea
+
+.phpunit.result.cache
+.phpunit.cache
+
+.phpstan
+.php-cs-fixer.cache
diff --git a/.php-cs-fixer.php b/.php-cs-fixer.php
new file mode 100644
index 0000000..50eee83
--- /dev/null
+++ b/.php-cs-fixer.php
@@ -0,0 +1,14 @@
+<?php
+
+$finder = Symfony\Component\Finder\Finder::create()
+    ->in(__DIR__.'/src')
+    ->in(__DIR__.'/test')
+    ->exclude('vendor');
+
+$config = new PhpCsFixer\Config();
+
+return $config->setRules([
+        '@PSR12' => true,
+        'array_syntax' => ['syntax' => 'short'],
+    ])
+    ->setFinder($finder);
diff --git a/.travis.yml b/.travis.yml
index a04b9d5..8a53b0e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -13,22 +13,22 @@ env:
 
 matrix:
   include:
-    - php: 7.2
+    - php: 8.1
       env:
         - DEPS=lowest
-    - php: 7.2
+    - php: 8.1
       env:
         - DEPS=latest
-    - php: 7.3
+    - php: 8.2
       env:
         - DEPS=lowest
-    - php: 7.3
+    - php: 8.2
       env:
         - DEPS=latest
-    - php: 7.4
+    - php: 8.3
       env:
         - DEPS=lowest
-    - php: 7.4
+    - php: 8.3
       env:
         - DEPS=latest
 
@@ -49,4 +49,4 @@ after_script:
   - if [[ $TEST_COVERAGE == 'true' ]]; then vendor/bin/php-coveralls -v ; fi
 
 notifications:
-  email: false
\ No newline at end of file
+  email: false
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..e4ce528
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,4 @@
+# Changelog
+
+## 2.0.0
+* [TASK][CRM-63243](https://jira.trans.eu/browse/CRM-63243) Adjust code for php ^8.1
diff --git a/composer.json b/composer.json
index ea6e63d..a5eb5ef 100644
--- a/composer.json
+++ b/composer.json
@@ -1,15 +1,25 @@
 {
   "name": "rstgroup/object-builder",
   "description": "Dynamic build of object",
+  "version": "2.0.0",
   "license": "MIT",
   "keywords": [],
+  "authors": [
+    {
+      "name": "Team ABW",
+      "email": "abw@rst.com.pl"
+    }
+  ],
   "require": {
-    "php": "^7.2",
-    "phpstan/phpdoc-parser": "^0.3.0 || ^0.4.0 || ^0.5.0",
-    "roave/better-reflection": "^3.0 || ^4.0"
+    "php": "^8.1",
+    "phpstan/phpdoc-parser": "^1.29.0",
+    "roave/better-reflection": "~6.25.0"
   },
   "require-dev": {
-    "phpunit/phpunit": "^7.2"
+    "friendsofphp/php-cs-fixer": "^3.58",
+    "phpstan/phpstan": "^1.11",
+    "phpunit/phpunit": "^10.0.0",
+    "rector/rector": "^1.1"
   },
   "autoload": {
     "psr-4": {
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..bd143ab
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,6 @@
+parameters:
+    level: 6
+    tmpDir: .phpstan
+    paths:
+        - src
+        - test
diff --git a/phpunit.xml b/phpunit.xml
index 2db3447..9e559d4 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,29 +1,26 @@
-<phpunit bootstrap="vendor/autoload.php"
-         backupStaticAttributes="false"
+<?xml version="1.0"?>
+<phpunit
+         bootstrap="vendor/autoload.php"
          backupGlobals="false"
          colors="true"
          stopOnError="false"
          stopOnFailure="false"
          stopOnIncomplete="false"
          stopOnSkipped="false"
-         convertErrorsToExceptions="true"
-         convertNoticesToExceptions="true"
-         convertWarningsToExceptions="true"
-         verbose="true">
-
-    <testsuites>
-        <testsuite name="unit">
-            <directory>test/unit/</directory>
-        </testsuite>
-    </testsuites>
-
-    <filter>
-        <whitelist processUncoveredFilesFromWhitelist="true">
-            <directory suffix=".php">src</directory>
-            <exclude>
-                <directory suffix=".php">test</directory>
-            </exclude>
-        </whitelist>
-    </filter>
-
-</phpunit>
\ No newline at end of file
+         cacheDirectory=".phpunit.cache"
+         backupStaticProperties="false"
+>
+  <testsuites>
+    <testsuite name="unit">
+      <directory>test/unit/</directory>
+    </testsuite>
+  </testsuites>
+  <source>
+    <include>
+      <directory suffix=".php">src</directory>
+    </include>
+    <exclude>
+      <directory suffix=".php">test</directory>
+    </exclude>
+  </source>
+</phpunit>
diff --git a/rector.php b/rector.php
new file mode 100755
index 0000000..3575543
--- /dev/null
+++ b/rector.php
@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use Rector\PHPUnit\Set\PHPUnitSetList;
+use Rector\Set\ValueObject\LevelSetList;
+use Rector\Set\ValueObject\SetList;
+
+return static function (RectorConfig $rectorConfig): void {
+    $rectorConfig->paths([
+        __DIR__ . '/src',
+        __DIR__ . '/test',
+    ]);
+
+    $rectorConfig->sets([
+        LevelSetList::UP_TO_PHP_81,
+    ]);
+
+    $rectorConfig->import(SetList::CODE_QUALITY);
+    $rectorConfig->import(SetList::TYPE_DECLARATION);
+    $rectorConfig->import(SetList::CODING_STYLE);
+
+    $rectorConfig->sets([
+        PHPUnitSetList::PHPUNIT_70,
+        PHPUnitSetList::PHPUNIT_80,
+        PHPUnitSetList::PHPUNIT_90,
+        PHPUnitSetList::PHPUNIT_100,
+        PHPUnitSetList::PHPUNIT_CODE_QUALITY,
+    ]);
+
+};
diff --git a/src/Builder.php b/src/Builder.php
index fee1b06..996f754 100644
--- a/src/Builder.php
+++ b/src/Builder.php
@@ -1,8 +1,15 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder;
 
 interface Builder
 {
+    /**
+     * @param string $class
+     * @param mixed[] $data
+     * @return object
+     */
     public function build(string $class, array $data): object;
 }
diff --git a/src/Builder/ParameterNameStrategy.php b/src/Builder/ParameterNameStrategy.php
index b48ae92..0b3c121 100644
--- a/src/Builder/ParameterNameStrategy.php
+++ b/src/Builder/ParameterNameStrategy.php
@@ -1,9 +1,12 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Builder;
 
 interface ParameterNameStrategy
 {
     public function isFulfilled(string $parameterName): bool;
+
     public function getName(string $parameterName): string;
 }
diff --git a/src/Builder/ParameterNameStrategy/Simple.php b/src/Builder/ParameterNameStrategy/Simple.php
index b8eed8e..7db6654 100644
--- a/src/Builder/ParameterNameStrategy/Simple.php
+++ b/src/Builder/ParameterNameStrategy/Simple.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Builder\ParameterNameStrategy;
 
diff --git a/src/Builder/ParameterNameStrategy/SnakeCase.php b/src/Builder/ParameterNameStrategy/SnakeCase.php
index 600db9c..a6b0123 100644
--- a/src/Builder/ParameterNameStrategy/SnakeCase.php
+++ b/src/Builder/ParameterNameStrategy/SnakeCase.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Builder\ParameterNameStrategy;
 
diff --git a/src/Builder/Reflection.php b/src/Builder/Reflection.php
index 8792eca..0d244de 100644
--- a/src/Builder/Reflection.php
+++ b/src/Builder/Reflection.php
@@ -1,7 +1,10 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Builder;
 
+use Iterator;
 use PhpParser\Node\Stmt;
 use PHPStan\PhpDocParser\Lexer\Lexer;
 use PHPStan\PhpDocParser\Parser\ConstExprParser;
@@ -9,7 +12,9 @@
 use PHPStan\PhpDocParser\Parser\TokenIterator;
 use PHPStan\PhpDocParser\Parser\TypeParser;
 use ReflectionClass;
+use ReflectionException;
 use ReflectionMethod;
+use ReflectionNamedType;
 use ReflectionParameter;
 use Roave\BetterReflection\BetterReflection;
 use RstGroup\ObjectBuilder\Builder;
@@ -18,15 +23,11 @@
 
 final class Reflection implements Builder
 {
-    private $parameterNameStrategy;
-
-    public function __construct(ParameterNameStrategy $parameterNameStrategy)
+    public function __construct(private readonly ParameterNameStrategy $parameterNameStrategy)
     {
-        $this->parameterNameStrategy = $parameterNameStrategy;
     }
 
     /**
-     * @param mixed[] $data
      * @throws BuilderException
      */
     public function build(string $class, array $data): object
@@ -34,18 +35,18 @@ public function build(string $class, array $data): object
         try {
             $classReflection = new ReflectionClass($class);
 
-            /** @var ReflectionMethod $constructorMethod */
+            /** @var ReflectionMethod|null $constructor */
             $constructor = $classReflection->getConstructor();
 
             $parameters = iterator_to_array($this->collect($constructor, $data));
 
             return new $class(...$parameters);
-        } catch (Throwable $exception) {
-            throw new BuilderException('Cant build object', 0, $exception);
+        } catch (Throwable $throwable) {
+            throw new BuilderException('Cant build object', 0, $throwable);
         }
     }
 
-    private function collect(ReflectionMethod $constructor, array $data): iterable
+    private function collect(ReflectionMethod $constructor, array $data): Iterator
     {
         foreach ($constructor->getParameters() as $parameter) {
             $name = $parameter->getName();
@@ -84,17 +85,19 @@ private function parameterDataIsInData(string $parameterName, array $data): bool
     }
 
     /**
-     * @param mixed $data
-     * @return mixed
+     * @throws BuilderException
+     * @throws ReflectionException
      */
-    private function buildParameter(ReflectionParameter $parameter, $data, ReflectionMethod $constructor)
+    private function buildParameter(ReflectionParameter $parameter, mixed $data, ReflectionMethod $constructor): mixed
     {
-        $class = $parameter->getClass();
+        $parameterType = $parameter->getType();
+
+        if ($parameterType instanceof ReflectionNamedType && !$parameterType->isBuiltin()) {
+            $parameterClass = new ReflectionClass($parameterType->getName());
 
-        if (null !== $class) {
-            $name = $class->getName();
+            $name = $parameterClass->getName();
             /** @var ReflectionMethod $constructorMethod */
-            $constructorMethod = $class->getConstructor();
+            $constructorMethod = $parameterClass->getConstructor();
             $parameters = [];
 
             if (null !== $constructorMethod) {
@@ -104,7 +107,7 @@ private function buildParameter(ReflectionParameter $parameter, $data, Reflectio
             return new $name(...$parameters);
         }
 
-        if ($parameter->isArray()) {
+        if ($parameterType instanceof ReflectionNamedType && $parameterType->getName() === 'array') {
             $parser = new PhpDocParser(new TypeParser(), new ConstExprParser());
             $node = $parser->parse(new TokenIterator((new Lexer())->tokenize($constructor->getDocComment())));
             foreach ($node->getParamTagValues() as $node) {
@@ -113,6 +116,7 @@ private function buildParameter(ReflectionParameter $parameter, $data, Reflectio
                     if ($this->isScalar($typeName)) {
                         continue;
                     }
+
                     $list = [];
 
                     $parser = (new BetterReflection())->phpParser();
@@ -122,7 +126,7 @@ private function buildParameter(ReflectionParameter $parameter, $data, Reflectio
                     $uses = $this->getUseStmts($namespace);
                     $namespaces = $this->getUsesNamespaces($uses);
 
-                    foreach($data as $objectConstructorData) {
+                    foreach ($data as $objectConstructorData) {
                         $list[] = $this->build(
                             $this->getFullClassName($typeName, $namespaces, $constructor->getDeclaringClass()),
                             $objectConstructorData
@@ -170,7 +174,7 @@ private function getUseStmts(Stmt\Namespace_ $node): array
         $uses = [];
         foreach ($node->stmts as $node) {
             if ($node instanceof Stmt\Use_) {
-                $uses[]= $node;
+                $uses[] = $node;
             }
         }
 
@@ -197,7 +201,7 @@ private function getFullClassName(string $name, array $namespaces, ReflectionCla
             return $name;
         }
 
-        if (0 === count($namespaces)) {
+        if ([] === $namespaces) {
             return $class->getNamespaceName() . '\\' . $name;
         }
 
diff --git a/src/BuilderException.php b/src/BuilderException.php
index 5bee453..82042e2 100644
--- a/src/BuilderException.php
+++ b/src/BuilderException.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder;
 
@@ -6,5 +8,4 @@
 
 final class BuilderException extends Exception
 {
-
 }
diff --git a/test/ListOfObjectsWithScalarTypedArrayAndObjectListConstructor.php b/test/ListOfObjectsWithScalarTypedArrayAndObjectListConstructor.php
index efdd148..5d1dd72 100644
--- a/test/ListOfObjectsWithScalarTypedArrayAndObjectListConstructor.php
+++ b/test/ListOfObjectsWithScalarTypedArrayAndObjectListConstructor.php
@@ -1,19 +1,16 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test;
 
-class ListOfObjectsWithScalarTypedArrayAndObjectListConstructor
+final class ListOfObjectsWithScalarTypedArrayAndObjectListConstructor
 {
-    public $list1;
-    public $list2;
-
     /**
      * @param string[] $list1
      * @param SimpleScalarConstructor[] $list2
      */
-    public function __construct(array $list1, array $list2)
+    public function __construct(public array $list1, public array $list2)
     {
-        $this->list1 = $list1;
-        $this->list2 = $list2;
     }
 }
diff --git a/test/ListOfObjectsWithScalarTypedArrayConstructor.php b/test/ListOfObjectsWithScalarTypedArrayConstructor.php
index ed7b41c..ef6da7c 100644
--- a/test/ListOfObjectsWithScalarTypedArrayConstructor.php
+++ b/test/ListOfObjectsWithScalarTypedArrayConstructor.php
@@ -1,19 +1,16 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test;
 
-class ListOfObjectsWithScalarTypedArrayConstructor
+final class ListOfObjectsWithScalarTypedArrayConstructor
 {
-    public $list1;
-    public $list2;
-
     /**
      * @param string[] $list1
      * @param mixed[] $list2
      */
-    public function __construct(array $list1, array $list2)
+    public function __construct(public array $list1, public array $list2)
     {
-        $this->list1 = $list1;
-        $this->list2 = $list2;
     }
 }
diff --git a/test/ListOfObjectsWithUseStmtConstructor.php b/test/ListOfObjectsWithUseStmtConstructor.php
index 7fac801..60f2975 100644
--- a/test/ListOfObjectsWithUseStmtConstructor.php
+++ b/test/ListOfObjectsWithUseStmtConstructor.php
@@ -1,21 +1,24 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test;
 
 use RstGroup\ObjectBuilder\Test\Object\SomeObject;
 use RstGroup\ObjectBuilder\Test\Object\SomeSecondObject;
 
-class ListOfObjectsWithUseStmtConstructor
+final class ListOfObjectsWithUseStmtConstructor
 {
-    public $list;
-    public $object;
+    /**
+     * @var SomeObject
+     */
+    public SomeObject $object;
 
     /**
      * @param SomeSecondObject[] $list
      */
-    public function __construct(array $list)
+    public function __construct(public array $list)
     {
-        $this->list = $list;
         $this->object = new SomeObject();
     }
 }
diff --git a/test/ListOfObjectsWithoutUseButWithFQNTypedArrayConstructor.php b/test/ListOfObjectsWithoutUseButWithFQNTypedArrayConstructor.php
index 1aeabf4..9aeeac1 100644
--- a/test/ListOfObjectsWithoutUseButWithFQNTypedArrayConstructor.php
+++ b/test/ListOfObjectsWithoutUseButWithFQNTypedArrayConstructor.php
@@ -1,16 +1,17 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test;
 
-class ListOfObjectsWithoutUseButWithFQNTypedArrayConstructor
-{
-    public $list;
+use RstGroup\ObjectBuilder\Test\Object\SomeObject;
 
+final class ListOfObjectsWithoutUseButWithFQNTypedArrayConstructor
+{
     /**
-     * @param \RstGroup\ObjectBuilder\Test\Object\SomeObject[] $list
+     * @param SomeObject[] $list
      */
-    public function __construct(array $list)
+    public function __construct(public array $list)
     {
-        $this->list = $list;
     }
 }
diff --git a/test/ListOfObjectsWithoutUseStmtConstructor.php b/test/ListOfObjectsWithoutUseStmtConstructor.php
index 38db6b5..ce51c72 100644
--- a/test/ListOfObjectsWithoutUseStmtConstructor.php
+++ b/test/ListOfObjectsWithoutUseStmtConstructor.php
@@ -1,16 +1,15 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test;
 
-class ListOfObjectsWithoutUseStmtConstructor
+final class ListOfObjectsWithoutUseStmtConstructor
 {
-    public $list;
-
     /**
      * @param SimpleScalarConstructor[] $list
      */
-    public function __construct(array $list)
+    public function __construct(public array $list)
     {
-        $this->list = $list;
     }
 }
diff --git a/test/Object/SomeObject.php b/test/Object/SomeObject.php
index 59e8e8c..2b6390a 100644
--- a/test/Object/SomeObject.php
+++ b/test/Object/SomeObject.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test\Object;
 
diff --git a/test/Object/SomeSecondObject.php b/test/Object/SomeSecondObject.php
index b972c95..d5bbbe8 100644
--- a/test/Object/SomeSecondObject.php
+++ b/test/Object/SomeSecondObject.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test\Object;
 
diff --git a/test/SimpleMixedConstructor.php b/test/SimpleMixedConstructor.php
index b4dac09..78753d5 100644
--- a/test/SimpleMixedConstructor.php
+++ b/test/SimpleMixedConstructor.php
@@ -1,17 +1,12 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test;
 
-class SimpleMixedConstructor
+final class SimpleMixedConstructor
 {
-    public $someString;
-    public $someInt;
-    public $someObject;
-
-    public function __construct(string $someString, int $someInt, SomeObjectWithEmptyConstructor $someObject)
+    public function __construct(public string $someString, public int $someInt, public SomeObjectWithEmptyConstructor $someObject)
     {
-        $this->someString = $someString;
-        $this->someInt = $someInt;
-        $this->someObject = $someObject;
     }
 }
diff --git a/test/SimpleMixedConstructorWithDefaultValue.php b/test/SimpleMixedConstructorWithDefaultValue.php
index d44b028..0ff92d6 100644
--- a/test/SimpleMixedConstructorWithDefaultValue.php
+++ b/test/SimpleMixedConstructorWithDefaultValue.php
@@ -1,20 +1,15 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test;
 
-class SimpleMixedConstructorWithDefaultValue
+final class SimpleMixedConstructorWithDefaultValue
 {
-    public $someString;
-    public $someInt;
-    public $someObject;
-
     public function __construct(
-        SomeObjectWithEmptyConstructor $someObject,
-        string $someString = 'some string',
-        int $someInt = 999
+        public SomeObjectWithEmptyConstructor $someObject,
+        public string $someString = 'some string',
+        public int $someInt = 999
     ) {
-        $this->someString = $someString;
-        $this->someInt = $someInt;
-        $this->someObject = $someObject;
     }
 }
diff --git a/test/SimpleNullableConstructor.php b/test/SimpleNullableConstructor.php
index c9b4416..b146db6 100644
--- a/test/SimpleNullableConstructor.php
+++ b/test/SimpleNullableConstructor.php
@@ -1,17 +1,12 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test;
 
-class SimpleNullableConstructor
+final class SimpleNullableConstructor
 {
-    public $someInt;
-    public $someString1;
-    public $someString2;
-
-    public function __construct(string $someString1, ?int $someInt, string $someString2)
+    public function __construct(public string $someString1, public ?int $someInt, public string $someString2)
     {
-        $this->someInt = $someInt;
-        $this->someString1 = $someString1;
-        $this->someString2 = $someString2;
     }
 }
diff --git a/test/SimpleScalarConstructor.php b/test/SimpleScalarConstructor.php
index d0927c4..f41236a 100644
--- a/test/SimpleScalarConstructor.php
+++ b/test/SimpleScalarConstructor.php
@@ -1,15 +1,12 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test;
 
-class SimpleScalarConstructor
+final class SimpleScalarConstructor
 {
-    public $someString;
-    public $someInt;
-
-    public function __construct(string $someString, int $someInt)
+    public function __construct(public string $someString, public int $someInt)
     {
-        $this->someString = $someString;
-        $this->someInt = $someInt;
     }
 }
diff --git a/test/SomeAggregateRoot.php b/test/SomeAggregateRoot.php
index ab48e11..1fdb0f7 100644
--- a/test/SomeAggregateRoot.php
+++ b/test/SomeAggregateRoot.php
@@ -1,23 +1,16 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test;
 
-class SomeAggregateRoot
+final class SomeAggregateRoot
 {
-    public $someString;
-    public $simpleObject1;
-    public $simpleObject2;
-    public $someInt;
-
     public function __construct(
-        string $someString,
-        SimpleScalarConstructor $simpleObject1,
-        SimpleMixedConstructor $simpleObject2,
-        int $someInt
+        public string $someString,
+        public SimpleScalarConstructor $simpleObject1,
+        public SimpleMixedConstructor $simpleObject2,
+        public int $someInt
     ) {
-        $this->someString = $someString;
-        $this->simpleObject1 = $simpleObject1;
-        $this->simpleObject2 = $simpleObject2;
-        $this->someInt = $someInt;
     }
 }
diff --git a/test/SomeObjectWithEmptyConstructor.php b/test/SomeObjectWithEmptyConstructor.php
index 05795b1..6664196 100644
--- a/test/SomeObjectWithEmptyConstructor.php
+++ b/test/SomeObjectWithEmptyConstructor.php
@@ -1,8 +1,9 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test;
 
-class SomeObjectWithEmptyConstructor
+final class SomeObjectWithEmptyConstructor
 {
-
 }
diff --git a/test/unit/Builder/ParameterNameStrategy/SimpleTest.php b/test/unit/Builder/ParameterNameStrategy/SimpleTest.php
index a288125..cb27712 100644
--- a/test/unit/Builder/ParameterNameStrategy/SimpleTest.php
+++ b/test/unit/Builder/ParameterNameStrategy/SimpleTest.php
@@ -1,68 +1,62 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test\unit\Builder\ParameterNameStrategy;
 
+use Iterator;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\Attributes\Test;
 use PHPUnit\Framework\TestCase;
 use RstGroup\ObjectBuilder\Builder\ParameterNameStrategy\Simple;
 
-class SimpleTest extends TestCase
+final class SimpleTest extends TestCase
 {
-    /** @var Simple */
-    private static $strategy;
+    private Simple $strategy;
 
-    public static function setUpBeforeClass()
+    public function setUp(): void
     {
-        static::$strategy = new Simple();
+        $this->strategy = new Simple();
     }
 
-    /**
-     * @test
-     * @dataProvider validStrings
-     */
-    public function simpleStrategyReturnTrueForStringsWithoutUnderscoreMinusAndSpace(string $string)
+    #[DataProvider('validStrings')]
+    #[Test]
+    public function simpleStrategyReturnTrueForStringsWithoutUnderscoreMinusAndSpace(string $string): void
     {
-        $isFulfilled = static::$strategy->isFulfilled($string);
+        $isFulfilled = $this->strategy->isFulfilled($string);
 
         $this->assertTrue($isFulfilled);
     }
 
-    /**
-     * @test
-     * @dataProvider invalidStrings
-     */
-    public function simpleStrategyReturnFalseForStringsWitUnderscoreOrMinusOrSpace(string $string)
+    #[DataProvider('invalidStrings')]
+    #[Test]
+    public function simpleStrategyReturnFalseForStringsWitUnderscoreOrMinusOrSpace(string $string): void
     {
-        $isFulfilled = static::$strategy->isFulfilled($string);
+        $isFulfilled = $this->strategy->isFulfilled($string);
 
         $this->assertFalse($isFulfilled);
     }
 
-    /** @test */
-    public function simpleStrategyReturnGivenParameterWithoutModification()
+    #[Test]
+    public function simpleStrategyReturnGivenParameterWithoutModification(): void
     {
-        $string = static::$strategy->getName('simpleCamelCase');
+        $string = $this->strategy->getName('simpleCamelCase');
 
         $this->assertSame('simpleCamelCase', $string);
     }
 
-    /** @return string[][] */
-    public function validStrings(): array
+    public static function validStrings(): Iterator
     {
-        return [
-            'simple string' => ['string'],
-            'camelCase string' => ['validString'],
-            'string with number' => ['valid1'],
-            'camelCase with number' => ['validString123String'],
-        ];
+        yield 'simple string' => ['string'];
+        yield 'camelCase string' => ['validString'];
+        yield 'string with number' => ['valid1'];
+        yield 'camelCase with number' => ['validString123String'];
     }
 
-    /** @return string[][] */
-    public function invalidStrings(): array
+    public static function invalidStrings(): Iterator
     {
-        return [
-            'string with space' => ['string string'],
-            'string with underscore' => ['string_string'],
-            'string with minus' => ['string-string'],
-        ];
+        yield 'string with space' => ['string string'];
+        yield 'string with underscore' => ['string_string'];
+        yield 'string with minus' => ['string-string'];
     }
 }
diff --git a/test/unit/Builder/ParameterNameStrategy/SnakeCaseTest.php b/test/unit/Builder/ParameterNameStrategy/SnakeCaseTest.php
index ac8ec64..c66cfd1 100644
--- a/test/unit/Builder/ParameterNameStrategy/SnakeCaseTest.php
+++ b/test/unit/Builder/ParameterNameStrategy/SnakeCaseTest.php
@@ -1,67 +1,60 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test\unit\Builder\ParameterNameStrategy;
 
+use Iterator;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\Attributes\Test;
 use PHPUnit\Framework\TestCase;
-use RstGroup\ObjectBuilder\Builder\ParameterNameStrategy\Simple;
 use RstGroup\ObjectBuilder\Builder\ParameterNameStrategy\SnakeCase;
 
-class SnakeCaseTest extends TestCase
+final class SnakeCaseTest extends TestCase
 {
-    /** @var SnakeCase */
-    private static $strategy;
+    private SnakeCase $strategy;
 
-    public static function setUpBeforeClass()
+    public function setUp(): void
     {
-        static::$strategy = new SnakeCase();
+        $this->strategy = new SnakeCase();
     }
 
-    /**
-     * @test
-     * @dataProvider validStrings
-     */
-    public function snakeCaseStrategyReturnTrueForStringsOnlyInSneakCaseFormat(string $string)
+    #[DataProvider('validStrings')]
+    #[Test]
+    public function snakeCaseStrategyReturnTrueForStringsOnlyInSneakCaseFormat(string $string): void
     {
-        $isFulfilled = static::$strategy->isFulfilled($string);
+        $isFulfilled = $this->strategy->isFulfilled($string);
 
         $this->assertTrue($isFulfilled);
     }
 
-    /**
-     * @test
-     * @dataProvider invalidStrings
-     */
-    public function snakeCaseStrategyReturnFalseForStringsWitUnderscoreOrSpace(string $string)
+    #[DataProvider('invalidStrings')]
+    #[Test]
+    public function snakeCaseStrategyReturnFalseForStringsWitUnderscoreOrSpace(string $string): void
     {
-        $isFulfilled = static::$strategy->isFulfilled($string);
+        $isFulfilled = $this->strategy->isFulfilled($string);
 
         $this->assertFalse($isFulfilled);
     }
 
-    /** @test */
-    public function snakeCaseStrategyReturnGivenParameterAsCamelCase()
+    #[Test]
+    public function snakeCaseStrategyReturnGivenParameterAsCamelCase(): void
     {
-        $string = static::$strategy->getName('simple_snake_case');
+        $string = $this->strategy->getName('simple_snake_case');
 
         $this->assertSame('simpleSnakeCase', $string);
     }
 
-    /** @return string[][] */
-    public function validStrings(): array
+    public static function validStrings(): Iterator
     {
-        return [
-            'simple string' => ['string'],
-            'sneak case string' => ['valid_string'],
-            'sneak case string with number' => ['valid_string_1'],
-        ];
+        yield 'simple string' => ['string'];
+        yield 'sneak case string' => ['valid_string'];
+        yield 'sneak case string with number' => ['valid_string_1'];
     }
 
-    /** @return string[][] */
-    public function invalidStrings(): array
+    public static function invalidStrings(): Iterator
     {
-        return [
-            'string with space' => ['string string'],
-            'string with minus' => ['string-string'],
-        ];
+        yield 'string with space' => ['string string'];
+        yield 'string with minus' => ['string-string'];
     }
 }
diff --git a/test/unit/Builder/ReflectionTest.php b/test/unit/Builder/ReflectionTest.php
index 0b48bce..2619a29 100644
--- a/test/unit/Builder/ReflectionTest.php
+++ b/test/unit/Builder/ReflectionTest.php
@@ -1,7 +1,10 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace RstGroup\ObjectBuilder\Test\unit\Builder;
 
+use PHPUnit\Framework\Attributes\Test;
 use PHPUnit\Framework\TestCase;
 use RstGroup\ObjectBuilder\Builder\ParameterNameStrategy\Simple;
 use RstGroup\ObjectBuilder\Builder\Reflection;
@@ -19,18 +22,17 @@
 use RstGroup\ObjectBuilder\Test\SomeAggregateRoot;
 use RstGroup\ObjectBuilder\Test\SomeObjectWithEmptyConstructor;
 
-class ReflectionTest extends TestCase
+final class ReflectionTest extends TestCase
 {
-    /** @var Reflection */
-    private static $builder;
+    private Reflection $builder;
 
-    public static function setUpBeforeClass()
+    public function setUp(): void
     {
-        static::$builder = new Reflection(new Simple());
+        $this->builder = new Reflection(new Simple());
     }
 
-    /** @test */
-    public function iCanBuildSimpleObjectWithScalarValuesInConstructor()
+    #[Test]
+    public function iCanBuildSimpleObjectWithScalarValuesInConstructor(): void
     {
         $data = [
             'someString' => 'some string',
@@ -39,15 +41,15 @@ public function iCanBuildSimpleObjectWithScalarValuesInConstructor()
         $class = SimpleScalarConstructor::class;
 
         /** @var SimpleScalarConstructor $object */
-        $object = static::$builder->build($class, $data);
+        $object = $this->builder->build($class, $data);
 
         $this->assertInstanceOf(SimpleScalarConstructor::class, $object);
         $this->assertSame('some string', $object->someString);
         $this->assertSame(999, $object->someInt);
     }
 
-    /** @test */
-    public function iCanBuildSimpleObjectWithScalarAndObjectValuesInConstructor()
+    #[Test]
+    public function iCanBuildSimpleObjectWithScalarAndObjectValuesInConstructor(): void
     {
         $data = [
             'someString' => 'some string',
@@ -57,7 +59,7 @@ public function iCanBuildSimpleObjectWithScalarAndObjectValuesInConstructor()
         $class = SimpleMixedConstructor::class;
 
         /** @var SimpleMixedConstructor $object */
-        $object = static::$builder->build($class, $data);
+        $object = $this->builder->build($class, $data);
 
         $this->assertInstanceOf(SimpleMixedConstructor::class, $object);
         $this->assertSame('some string', $object->someString);
@@ -65,8 +67,8 @@ public function iCanBuildSimpleObjectWithScalarAndObjectValuesInConstructor()
         $this->assertInstanceOf(SomeObjectWithEmptyConstructor::class, $object->someObject);
     }
 
-    /** @test */
-    public function iCanBuildSimpleObjectWithDefaultValuesInConstructor()
+    #[Test]
+    public function iCanBuildSimpleObjectWithDefaultValuesInConstructor(): void
     {
         $data = [
             'someObject' => [],
@@ -74,7 +76,7 @@ public function iCanBuildSimpleObjectWithDefaultValuesInConstructor()
         $class = SimpleMixedConstructorWithDefaultValue::class;
 
         /** @var SimpleMixedConstructorWithDefaultValue $object */
-        $object = static::$builder->build($class, $data);
+        $object = $this->builder->build($class, $data);
 
         $this->assertInstanceOf(SimpleMixedConstructorWithDefaultValue::class, $object);
         $this->assertSame('some string', $object->someString);
@@ -82,8 +84,8 @@ public function iCanBuildSimpleObjectWithDefaultValuesInConstructor()
         $this->assertInstanceOf(SomeObjectWithEmptyConstructor::class, $object->someObject);
     }
 
-    /** @test */
-    public function iCanBuildObjectWithObjectCollectionWithoutUseInConstructor()
+    #[Test]
+    public function iCanBuildObjectWithObjectCollectionWithoutUseInConstructor(): void
     {
         $data = [
             'list' => [
@@ -100,17 +102,15 @@ public function iCanBuildObjectWithObjectCollectionWithoutUseInConstructor()
         $class = ListOfObjectsWithoutUseStmtConstructor::class;
 
         /** @var ListOfObjectsWithoutUseStmtConstructor $object */
-        $object = static::$builder->build($class, $data);
+        $object = $this->builder->build($class, $data);
 
         $this->assertInstanceOf(ListOfObjectsWithoutUseStmtConstructor::class, $object);
         $this->assertCount(2, $object->list);
-        foreach($object->list as $element) {
-            $this->assertInstanceOf(SimpleScalarConstructor::class, $element);
-        }
+        $this->assertContainsOnlyInstancesOf(SimpleScalarConstructor::class, $object->list);
     }
 
-    /** @test */
-    public function iCanBuildObjectWithObjectCollectionWithUseInConstructor()
+    #[Test]
+    public function iCanBuildObjectWithObjectCollectionWithUseInConstructor(): void
     {
         $data = [
             'list' => [
@@ -121,17 +121,15 @@ public function iCanBuildObjectWithObjectCollectionWithUseInConstructor()
         $class = ListOfObjectsWithUseStmtConstructor::class;
 
         /** @var ListOfObjectsWithUseStmtConstructor $object */
-        $object = static::$builder->build($class, $data);
+        $object = $this->builder->build($class, $data);
 
         $this->assertInstanceOf(ListOfObjectsWithUseStmtConstructor::class, $object);
         $this->assertCount(2, $object->list);
-        foreach($object->list as $element) {
-            $this->assertInstanceOf(SomeSecondObject::class, $element);
-        }
+        $this->assertContainsOnlyInstancesOf(SomeSecondObject::class, $object->list);
     }
 
-    /** @test */
-    public function iCanBuildObjectWithObjectCollectionWithoutUseButWithFQNTypedArrayInConstructor()
+    #[Test]
+    public function iCanBuildObjectWithObjectCollectionWithoutUseButWithFQNTypedArrayInConstructor(): void
     {
         $data = [
             'list' => [
@@ -142,17 +140,15 @@ public function iCanBuildObjectWithObjectCollectionWithoutUseButWithFQNTypedArra
         $class = ListOfObjectsWithoutUseButWithFQNTypedArrayConstructor::class;
 
         /** @var ListOfObjectsWithoutUseButWithFQNTypedArrayConstructor $object */
-        $object = static::$builder->build($class, $data);
+        $object = $this->builder->build($class, $data);
 
         $this->assertInstanceOf(ListOfObjectsWithoutUseButWithFQNTypedArrayConstructor::class, $object);
         $this->assertCount(2, $object->list);
-        foreach($object->list as $element) {
-            $this->assertInstanceOf(SomeObject::class, $element);
-        }
+        $this->assertContainsOnlyInstancesOf(SomeObject::class, $object->list);
     }
 
-    /** @test */
-    public function iCanBuildObjectWithScalarCollectionTypedArrayInConstructor()
+    #[Test]
+    public function iCanBuildObjectWithScalarCollectionTypedArrayInConstructor(): void
     {
         $data = [
             'list1' => ['str', 'str'],
@@ -161,21 +157,22 @@ public function iCanBuildObjectWithScalarCollectionTypedArrayInConstructor()
         $class = ListOfObjectsWithScalarTypedArrayConstructor::class;
 
         /** @var ListOfObjectsWithScalarTypedArrayConstructor $object */
-        $object = static::$builder->build($class, $data);
+        $object = $this->builder->build($class, $data);
 
         $this->assertInstanceOf(ListOfObjectsWithScalarTypedArrayConstructor::class, $object);
         $this->assertCount(2, $object->list1);
         $this->assertCount(2, $object->list2);
-        foreach($object->list1 as $element) {
+        foreach ($object->list1 as $element) {
             $this->assertSame('str', $element);
         }
-        foreach($object->list2 as $element) {
+
+        foreach ($object->list2 as $element) {
             $this->assertSame('str', $element);
         }
     }
 
-    /** @test */
-    public function iCanBuildObjectWithBothScalarAndObjectCollectionTypedArrayInConstructor()
+    #[Test]
+    public function iCanBuildObjectWithBothScalarAndObjectCollectionTypedArrayInConstructor(): void
     {
         $data = [
             'list1' => ['str', 'str'],
@@ -193,21 +190,20 @@ public function iCanBuildObjectWithBothScalarAndObjectCollectionTypedArrayInCons
         $class = ListOfObjectsWithScalarTypedArrayAndObjectListConstructor::class;
 
         /** @var ListOfObjectsWithScalarTypedArrayAndObjectListConstructor $object */
-        $object = static::$builder->build($class, $data);
+        $object = $this->builder->build($class, $data);
 
         $this->assertInstanceOf(ListOfObjectsWithScalarTypedArrayAndObjectListConstructor::class, $object);
         $this->assertCount(2, $object->list1);
         $this->assertCount(2, $object->list2);
-        foreach($object->list1 as $element) {
+        foreach ($object->list1 as $element) {
             $this->assertSame('str', $element);
         }
-        foreach($object->list2 as $element) {
-            $this->assertInstanceOf(SimpleScalarConstructor::class, $element);
-        }
+
+        $this->assertContainsOnlyInstancesOf(SimpleScalarConstructor::class, $object->list2);
     }
 
-    /** @test */
-    public function iCanBuildAdvancedObjectHierarchy()
+    #[Test]
+    public function iCanBuildAdvancedObjectHierarchy(): void
     {
         $data = [
             'someString' => 'some string',
@@ -225,7 +221,7 @@ public function iCanBuildAdvancedObjectHierarchy()
         $class = SomeAggregateRoot::class;
 
         /** @var SomeAggregateRoot $object */
-        $object = static::$builder->build($class, $data);
+        $object = $this->builder->build($class, $data);
 
         $this->assertInstanceOf(SomeAggregateRoot::class, $object);
         $this->assertSame('some string', $object->someString);
@@ -236,8 +232,8 @@ public function iCanBuildAdvancedObjectHierarchy()
         $this->assertSame(2, $object->simpleObject2->someInt);
     }
 
-    /** @test */
-    public function iCanBuildObjectWithNullableParameterWithoutDefaultValue()
+    #[Test]
+    public function iCanBuildObjectWithNullableParameterWithoutDefaultValue(): void
     {
         $data = [
             'someString1' => 'some string1',
@@ -246,7 +242,7 @@ public function iCanBuildObjectWithNullableParameterWithoutDefaultValue()
         $class = SimpleNullableConstructor::class;
 
         /** @var SimpleNullableConstructor $object */
-        $object = static::$builder->build($class, $data);
+        $object = $this->builder->build($class, $data);
 
         $this->assertInstanceOf(SimpleNullableConstructor::class, $object);
         $this->assertSame('some string1', $object->someString1);
@@ -254,8 +250,8 @@ public function iCanBuildObjectWithNullableParameterWithoutDefaultValue()
         $this->assertNull($object->someInt);
     }
 
-    /** @test */
-    public function iCanBuildObjectWithNullableParameterWithHimValueValue()
+    #[Test]
+    public function iCanBuildObjectWithNullableParameterWithHimValueValue(): void
     {
         $data = [
             'someString1' => 'some string1',
@@ -265,7 +261,7 @@ public function iCanBuildObjectWithNullableParameterWithHimValueValue()
         $class = SimpleNullableConstructor::class;
 
         /** @var SimpleNullableConstructor $object */
-        $object = static::$builder->build($class, $data);
+        $object = $this->builder->build($class, $data);
 
         $this->assertInstanceOf(SimpleNullableConstructor::class, $object);
         $this->assertSame('some string1', $object->someString1);