update deps & install rector

.travis.yml

@@ -3,9 +3,7 @@ language: php
 sudo: false
 
 php:
-  - 7.2
-  - 7.3
-  - 7.4snapshot
+  - 7.4
 
 matrix:
   fast_finish: true

Behavioral/ChainOfResponsibilities/Handler.php

@@ -3,14 +3,10 @@
 namespace DesignPatterns\Behavioral\ChainOfResponsibilities;
 
 use Psr\Http\Message\RequestInterface;
-use Psr\Http\Message\ResponseInterface;
 
 abstract class Handler
 {
-    /**
-     * @var Handler|null
-     */
-    private $successor = null;
+    private ?Handler $successor = null;
 
     public function __construct(Handler $handler = null)
     {
@@ -20,12 +16,8 @@ abstract class Handler
     /**
      * This approach by using a template method pattern ensures you that
      * each subclass will not forget to call the successor
-     *
-     * @param RequestInterface $request
-     *
-     * @return string|null
      */
-    final public function handle(RequestInterface $request)
+    final public function handle(RequestInterface $request): ?string
     {
         $processed = $this->processing($request);
 
@@ -37,5 +29,5 @@ abstract class Handler
         return $processed;
     }
 
-    abstract protected function processing(RequestInterface $request);
+    abstract protected function processing(RequestInterface $request): ?string;
 }

Behavioral/ChainOfResponsibilities/Responsible/HttpInMemoryCacheHandler.php

@@ -7,28 +7,16 @@ use Psr\Http\Message\RequestInterface;
 
 class HttpInMemoryCacheHandler extends Handler
 {
-    /**
-     * @var array
-     */
-    private $data;
+    private array $data;
 
-    /**
-     * @param array $data
-     * @param Handler|null $successor
-     */
-    public function __construct(array $data, Handler $successor = null)
+    public function __construct(array $data, ?Handler $successor = null)
     {
         parent::__construct($successor);
 
         $this->data = $data;
     }
 
-    /**
-     * @param RequestInterface $request
-     *
-     * @return string|null
-     */
-    protected function processing(RequestInterface $request)
+    protected function processing(RequestInterface $request): ?string
     {
         $key = sprintf(
             '%s?%s',

Behavioral/ChainOfResponsibilities/Responsible/SlowDatabaseHandler.php

@@ -7,12 +7,7 @@ use Psr\Http\Message\RequestInterface;
 
 class SlowDatabaseHandler extends Handler
 {
-    /**
-     * @param RequestInterface $request
-     *
-     * @return string|null
-     */
-    protected function processing(RequestInterface $request)
+    protected function processing(RequestInterface $request): ?string
     {
         // this is a mockup, in production code you would ask a slow (compared to in-memory) DB for the results
 

Behavioral/ChainOfResponsibilities/Tests/ChainTest.php

@@ -5,17 +5,13 @@ namespace DesignPatterns\Behavioral\ChainOfResponsibilities\Tests;
 use DesignPatterns\Behavioral\ChainOfResponsibilities\Handler;
 use DesignPatterns\Behavioral\ChainOfResponsibilities\Responsible\HttpInMemoryCacheHandler;
 use DesignPatterns\Behavioral\ChainOfResponsibilities\Responsible\SlowDatabaseHandler;
-use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use Psr\Http\Message\RequestInterface;
 use Psr\Http\Message\UriInterface;
 
 class ChainTest extends TestCase
 {
-    /**
-     * @var Handler
-     */
-    private $chain;
+    private Handler $chain;
 
     protected function setUp(): void
     {

Behavioral/Command/AddMessageDateCommand.php

@@ -8,16 +8,11 @@ namespace DesignPatterns\Behavioral\Command;
  */
 class AddMessageDateCommand implements UndoableCommand
 {
-    /**
-     * @var Receiver
-     */
-    private $output;
+    private Receiver $output;
 
     /**
      * Each concrete command is built with different receivers.
      * There can be one, many or completely no receivers, but there can be other commands in the parameters.
-     *
-     * @param Receiver $console
      */
     public function __construct(Receiver $console)
     {

Behavioral/Command/HelloCommand.php

@@ -8,16 +8,11 @@ namespace DesignPatterns\Behavioral\Command;
  */
 class HelloCommand implements Command
 {
-    /**
-     * @var Receiver
-     */
-    private $output;
+    private Receiver $output;
 
     /**
      * Each concrete command is built with different receivers.
      * There can be one, many or completely no receivers, but there can be other commands in the parameters
-     *
-     * @param Receiver $console
      */
     public function __construct(Receiver $console)
     {

Behavioral/Command/Invoker.php

@@ -8,16 +8,11 @@ namespace DesignPatterns\Behavioral\Command;
  */
 class Invoker
 {
-    /**
-     * @var Command
-     */
-    private $command;
+    private Command $command;
 
     /**
      * in the invoker we find this kind of method for subscribing the command
      * There can be also a stack, a list, a fixed set ...
-     *
-     * @param Command $cmd
      */
     public function setCommand(Command $cmd)
     {

Behavioral/Command/Receiver.php

@@ -3,23 +3,17 @@
 namespace DesignPatterns\Behavioral\Command;
 
 /**
- * Receiver is specific service with its own contract and can be only concrete.
+ * Receiver is a specific service with its own contract and can be only concrete.
  */
 class Receiver
 {
-    /**
-     * @var bool
-     */
-    private $enableDate = false;
+    private bool $enableDate = false;
 
     /**
      * @var string[]
      */
-    private $output = [];
+    private array $output = [];
 
-    /**
-     * @param string $str
-     */
     public function write(string $str)
     {
         if ($this->enableDate) {

Behavioral/Iterator/Book.php

@@ -4,15 +4,8 @@ namespace DesignPatterns\Behavioral\Iterator;
 
 class Book
 {
-    /**
-     * @var string
-     */
-    private $author;
-
-    /**
-     * @var string
-     */
-    private $title;
+    private string $author;
+    private string $title;
 
     public function __construct(string $title, string $author)
     {

Behavioral/Iterator/BookList.php

@@ -2,17 +2,16 @@
 
 namespace DesignPatterns\Behavioral\Iterator;
 
-class BookList implements \Countable, \Iterator
+use Countable;
+use Iterator;
+
+class BookList implements Countable, Iterator
 {
     /**
      * @var Book[]
      */
-    private $books = [];
-
-    /**
-     * @var int
-     */
-    private $currentIndex = 0;
+    private array $books = [];
+    private int $currentIndex = 0;
 
     public function addBook(Book $book)
     {

Behavioral/Mediator/Colleague.php

@@ -4,14 +4,8 @@ namespace DesignPatterns\Behavioral\Mediator;
 
 abstract class Colleague
 {
-    /**
-     * @var Mediator
-     */
-    protected $mediator;
+    protected Mediator $mediator;
 
-    /**
-     * @param Mediator $mediator
-     */
     public function setMediator(Mediator $mediator)
     {
         $this->mediator = $mediator;

Behavioral/Mediator/Tests/MediatorTest.php

@@ -11,7 +11,7 @@ class MediatorTest extends TestCase
 {
     public function testOutputHelloWorld()
     {
-        $mediator = new UserRepositoryUiMediator(new UserRepository(), new UI());
+        $mediator = new UserRepositoryUiMediator(new UserRepository(), new Ui());
 
         $this->expectOutputString('User: Dominik');
         $mediator->printInfoAbout('Dominik');

Behavioral/Mediator/UserRepositoryUiMediator.php

@@ -4,15 +4,8 @@ namespace DesignPatterns\Behavioral\Mediator;
 
 class UserRepositoryUiMediator implements Mediator
 {
-    /**
-     * @var UserRepository
-     */
-    private $userRepository;
-
-    /**
-     * @var Ui
-     */
-    private $ui;
+    private UserRepository $userRepository;
+    private Ui $ui;
 
     public function __construct(UserRepository $userRepository, Ui $ui)
     {

Behavioral/Memento/Memento.php

@@ -4,23 +4,14 @@ namespace DesignPatterns\Behavioral\Memento;
 
 class Memento
 {
-    /**
-     * @var State
-     */
-    private $state;
+    private State $state;
 
-    /**
-     * @param State $stateToSave
-     */
     public function __construct(State $stateToSave)
     {
         $this->state = $stateToSave;
     }
 
-    /**
-     * @return State
-     */
-    public function getState()
+    public function getState(): State
     {
         return $this->state;
     }

Behavioral/Memento/State.php

@@ -2,6 +2,8 @@
 
 namespace DesignPatterns\Behavioral\Memento;
 
+use InvalidArgumentException;
+
 class State
 {
     const STATE_CREATED = 'created';
@@ -9,24 +11,18 @@ class State
     const STATE_ASSIGNED = 'assigned';
     const STATE_CLOSED = 'closed';
 
-    /**
-     * @var string
-     */
-    private $state;
+    private string $state;
 
     /**
      * @var string[]
      */
-    private static $validStates = [
+    private static array $validStates = [
         self::STATE_CREATED,
         self::STATE_OPENED,
         self::STATE_ASSIGNED,
         self::STATE_CLOSED,
     ];
 
-    /**
-     * @param string $state
-     */
     public function __construct(string $state)
     {
         self::ensureIsValidState($state);
@@ -37,7 +33,7 @@ class State
     private static function ensureIsValidState(string $state)
     {
         if (!in_array($state, self::$validStates)) {
-            throw new \InvalidArgumentException('Invalid state given');
+            throw new InvalidArgumentException('Invalid state given');
         }
     }
 

Behavioral/Memento/Ticket.php

@@ -7,10 +7,7 @@ namespace DesignPatterns\Behavioral\Memento;
  */
 class Ticket
 {
-    /**
-     * @var State
-     */
-    private $currentState;
+    private State $currentState;
 
     public function __construct()
     {

Behavioral/NullObject/Service.php

@@ -4,14 +4,8 @@ namespace DesignPatterns\Behavioral\NullObject;
 
 class Service
 {
-    /**
-     * @var Logger
-     */
-    private $logger;
+    private Logger $logger;
 
-    /**
-     * @param Logger $logger
-     */
     public function __construct(Logger $logger)
     {
         $this->logger = $logger;

Behavioral/Observer/User.php

@@ -2,33 +2,30 @@
 
 namespace DesignPatterns\Behavioral\Observer;
 
+use SplSubject;
+use SplObjectStorage;
+use SplObserver;
+
 /**
  * User implements the observed object (called Subject), it maintains a list of observers and sends notifications to
  * them in case changes are made on the User object
  */
-class User implements \SplSubject
+class User implements SplSubject
 {
-    /**
-     * @var string
-     */
-    private $email;
-
-    /**
-     * @var \SplObjectStorage
-     */
-    private $observers;
+    private string $email;
+    private SplObjectStorage $observers;
 
     public function __construct()
     {
-        $this->observers = new \SplObjectStorage();
+        $this->observers = new SplObjectStorage();
     }
 
-    public function attach(\SplObserver $observer)
+    public function attach(SplObserver $observer)
     {
         $this->observers->attach($observer);
     }
 
-    public function detach(\SplObserver $observer)
+    public function detach(SplObserver $observer)
     {
         $this->observers->detach($observer);
     }
@@ -41,7 +38,7 @@ class User implements \SplSubject
 
     public function notify()
     {
-        /** @var \SplObserver $observer */
+        /** @var SplObserver $observer */
         foreach ($this->observers as $observer) {
             $observer->update($this);
         }

Behavioral/Observer/UserObserver.php

@@ -2,19 +2,18 @@
 
 namespace DesignPatterns\Behavioral\Observer;
 
+use SplObserver;
 use SplSubject;
 
-class UserObserver implements \SplObserver
+class UserObserver implements SplObserver
 {
     /**
      * @var SplSubject[]
      */
-    private $changedUsers = [];
+    private array $changedUsers = [];
 
     /**
      * It is called by the Subject, usually by SplSubject::notify()
-     *
-     * @param SplSubject $subject
      */
     public function update(SplSubject $subject)
     {

Behavioral/Specification/AndSpecification.php

@@ -7,7 +7,7 @@ class AndSpecification implements Specification
     /**
      * @var Specification[]
      */
-    private $specifications;
+    private array $specifications;
 
     /**
      * @param Specification[] $specifications

Behavioral/Specification/Item.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Behavioral\Specification;
 
 class Item
 {
-    /**
-     * @var float
-     */
-    private $price;
+    private float $price;
 
     public function __construct(float $price)
     {

Behavioral/Specification/NotSpecification.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Behavioral\Specification;
 
 class NotSpecification implements Specification
 {
-    /**
-     * @var Specification
-     */
-    private $specification;
+    private Specification $specification;
 
     public function __construct(Specification $specification)
     {

Behavioral/Specification/OrSpecification.php

@@ -7,7 +7,7 @@ class OrSpecification implements Specification
     /**
      * @var Specification[]
      */
-    private $specifications;
+    private array $specifications;
 
     /**
      * @param Specification[] $specifications
@@ -27,6 +27,7 @@ class OrSpecification implements Specification
                 return true;
             }
         }
+
         return false;
     }
 }

Behavioral/Specification/PriceSpecification.php

@@ -4,21 +4,10 @@ namespace DesignPatterns\Behavioral\Specification;
 
 class PriceSpecification implements Specification
 {
-    /**
-     * @var float|null
-     */
-    private $maxPrice;
+    private ?float $maxPrice;
+    private ?float $minPrice;
 
-    /**
-     * @var float|null
-     */
-    private $minPrice;
-
-    /**
-     * @param float $minPrice
-     * @param float $maxPrice
-     */
-    public function __construct($minPrice, $maxPrice)
+    public function __construct(?float $minPrice, ?float $maxPrice)
     {
         $this->minPrice = $minPrice;
         $this->maxPrice = $maxPrice;

Behavioral/State/OrderContext.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Behavioral\State;
 
 class OrderContext
 {
-    /**
-     * @var State
-     */
-    private $state;
+    private State $state;
 
     public static function create(): OrderContext
     {

Behavioral/Strategy/Context.php

@@ -4,17 +4,14 @@ namespace DesignPatterns\Behavioral\Strategy;
 
 class Context
 {
-    /**
-     * @var Comparator
-     */
-    private $comparator;
+    private Comparator $comparator;
 
     public function __construct(Comparator $comparator)
     {
         $this->comparator = $comparator;
     }
 
-    public function executeStrategy(array $elements) : array
+    public function executeStrategy(array $elements): array
     {
         uasort($elements, [$this->comparator, 'compare']);
 

Behavioral/Strategy/DateComparator.php

@@ -2,18 +2,14 @@
 
 namespace DesignPatterns\Behavioral\Strategy;
 
+use DateTime;
+
 class DateComparator implements Comparator
 {
-    /**
-     * @param mixed $a
-     * @param mixed $b
-     *
-     * @return int
-     */
     public function compare($a, $b): int
     {
-        $aDate = new \DateTime($a['date']);
-        $bDate = new \DateTime($b['date']);
+        $aDate = new DateTime($a['date']);
+        $bDate = new DateTime($b['date']);
 
         return $aDate <=> $bDate;
     }

Behavioral/Strategy/IdComparator.php

@@ -4,12 +4,6 @@ namespace DesignPatterns\Behavioral\Strategy;
 
 class IdComparator implements Comparator
 {
-    /**
-     * @param mixed $a
-     * @param mixed $b
-     *
-     * @return int
-     */
     public function compare($a, $b): int
     {
         return $a['id'] <=> $b['id'];

Behavioral/TemplateMethod/CityJourney.php

@@ -9,7 +9,7 @@ class CityJourney extends Journey
         return "Eat, drink, take photos and sleep";
     }
 
-    protected function buyGift(): string
+    protected function buyGift(): ?string
     {
         return "Buy a gift";
     }

Behavioral/TemplateMethod/Journey.php

@@ -7,7 +7,7 @@ abstract class Journey
     /**
      * @var string[]
      */
-    private $thingsToDo = [];
+    private array $thingsToDo = [];
 
     /**
      * This is the public service provided by this class and its subclasses.
@@ -37,10 +37,8 @@ abstract class Journey
     /**
      * This method is also part of the algorithm but it is optional.
      * You can override it only if you need to
-     *
-     * @return null|string
      */
-    protected function buyGift()
+    protected function buyGift(): ?string
     {
         return null;
     }

Behavioral/TemplateMethod/Tests/JourneyTest.php

@@ -2,14 +2,15 @@
 
 namespace DesignPatterns\Behavioral\TemplateMethod\Tests;
 
-use DesignPatterns\Behavioral\TemplateMethod;
+use DesignPatterns\Behavioral\TemplateMethod\BeachJourney;
+use DesignPatterns\Behavioral\TemplateMethod\CityJourney;
 use PHPUnit\Framework\TestCase;
 
 class JourneyTest extends TestCase
 {
     public function testCanGetOnVacationOnTheBeach()
     {
-        $beachJourney = new TemplateMethod\BeachJourney();
+        $beachJourney = new BeachJourney();
         $beachJourney->takeATrip();
 
         $this->assertSame(
@@ -20,7 +21,7 @@ class JourneyTest extends TestCase
 
     public function testCanGetOnAJourneyToACity()
     {
-        $cityJourney = new TemplateMethod\CityJourney();
+        $cityJourney = new CityJourney();
         $cityJourney->takeATrip();
 
         $this->assertSame(

Behavioral/Visitor/Group.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Behavioral\Visitor;
 
 class Group implements Role
 {
-    /**
-     * @var string
-     */
-    private $name;
+    private string $name;
 
     public function __construct(string $name)
     {

Behavioral/Visitor/RecordingVisitor.php

@@ -7,7 +7,7 @@ class RecordingVisitor implements RoleVisitor
     /**
      * @var Role[]
      */
-    private $visited = [];
+    private array $visited = [];
 
     public function visitGroup(Group $role)
     {

Behavioral/Visitor/Tests/VisitorTest.php

@@ -2,35 +2,34 @@
 
 namespace DesignPatterns\Tests\Visitor\Tests;
 
+use DesignPatterns\Behavioral\Visitor\RecordingVisitor;
+use DesignPatterns\Behavioral\Visitor\User;
+use DesignPatterns\Behavioral\Visitor\Group;
+use DesignPatterns\Behavioral\Visitor\Role;
 use DesignPatterns\Behavioral\Visitor;
 use PHPUnit\Framework\TestCase;
 
 class VisitorTest extends TestCase
 {
-    /**
-     * @var Visitor\RecordingVisitor
-     */
-    private $visitor;
+    private RecordingVisitor $visitor;
 
     protected function setUp(): void
     {
-        $this->visitor = new Visitor\RecordingVisitor();
+        $this->visitor = new RecordingVisitor();
     }
 
     public function provideRoles()
     {
         return [
-            [new Visitor\User('Dominik')],
-            [new Visitor\Group('Administrators')],
+            [new User('Dominik')],
+            [new Group('Administrators')],
         ];
     }
 
     /**
      * @dataProvider provideRoles
-     *
-     * @param Visitor\Role $role
      */
-    public function testVisitSomeRole(Visitor\Role $role)
+    public function testVisitSomeRole(Role $role)
     {
         $role->accept($this->visitor);
         $this->assertSame($role, $this->visitor->getVisited()[0]);

Behavioral/Visitor/User.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Behavioral\Visitor;
 
 class User implements Role
 {
-    /**
-     * @var string
-     */
-    private $name;
+    private string $name;
 
     public function __construct(string $name)
     {

Creational/Builder/CarBuilder.php

@@ -2,38 +2,39 @@
 
 namespace DesignPatterns\Creational\Builder;
 
+use DesignPatterns\Creational\Builder\Parts\Door;
+use DesignPatterns\Creational\Builder\Parts\Engine;
+use DesignPatterns\Creational\Builder\Parts\Wheel;
+use DesignPatterns\Creational\Builder\Parts\Car;
 use DesignPatterns\Creational\Builder\Parts\Vehicle;
 
 class CarBuilder implements Builder
 {
-    /**
-     * @var Parts\Car
-     */
-    private $car;
+    private Car $car;
 
     public function addDoors()
     {
-        $this->car->setPart('rightDoor', new Parts\Door());
-        $this->car->setPart('leftDoor', new Parts\Door());
-        $this->car->setPart('trunkLid', new Parts\Door());
+        $this->car->setPart('rightDoor', new Door());
+        $this->car->setPart('leftDoor', new Door());
+        $this->car->setPart('trunkLid', new Door());
     }
 
     public function addEngine()
     {
-        $this->car->setPart('engine', new Parts\Engine());
+        $this->car->setPart('engine', new Engine());
     }
 
     public function addWheel()
     {
-        $this->car->setPart('wheelLF', new Parts\Wheel());
-        $this->car->setPart('wheelRF', new Parts\Wheel());
-        $this->car->setPart('wheelLR', new Parts\Wheel());
-        $this->car->setPart('wheelRR', new Parts\Wheel());
+        $this->car->setPart('wheelLF', new Wheel());
+        $this->car->setPart('wheelRF', new Wheel());
+        $this->car->setPart('wheelLR', new Wheel());
+        $this->car->setPart('wheelRR', new Wheel());
     }
 
     public function createVehicle()
     {
-        $this->car = new Parts\Car();
+        $this->car = new Car();
     }
 
     public function getVehicle(): Vehicle

Creational/Builder/Parts/Vehicle.php

@@ -7,13 +7,9 @@ abstract class Vehicle
     /**
      * @var object[]
      */
-    private $data = [];
+    private array $data = [];
 
-    /**
-     * @param string $key
-     * @param object $value
-     */
-    public function setPart($key, $value)
+    public function setPart(string $key, object $value)
     {
         $this->data[$key] = $value;
     }

Creational/Builder/TruckBuilder.php

@@ -2,39 +2,40 @@
 
 namespace DesignPatterns\Creational\Builder;
 
+use DesignPatterns\Creational\Builder\Parts\Door;
+use DesignPatterns\Creational\Builder\Parts\Engine;
+use DesignPatterns\Creational\Builder\Parts\Wheel;
+use DesignPatterns\Creational\Builder\Parts\Truck;
 use DesignPatterns\Creational\Builder\Parts\Vehicle;
 
 class TruckBuilder implements Builder
 {
-    /**
-     * @var Parts\Truck
-     */
-    private $truck;
+    private Truck $truck;
 
     public function addDoors()
     {
-        $this->truck->setPart('rightDoor', new Parts\Door());
-        $this->truck->setPart('leftDoor', new Parts\Door());
+        $this->truck->setPart('rightDoor', new Door());
+        $this->truck->setPart('leftDoor', new Door());
     }
 
     public function addEngine()
     {
-        $this->truck->setPart('truckEngine', new Parts\Engine());
+        $this->truck->setPart('truckEngine', new Engine());
     }
 
     public function addWheel()
     {
-        $this->truck->setPart('wheel1', new Parts\Wheel());
-        $this->truck->setPart('wheel2', new Parts\Wheel());
-        $this->truck->setPart('wheel3', new Parts\Wheel());
-        $this->truck->setPart('wheel4', new Parts\Wheel());
-        $this->truck->setPart('wheel5', new Parts\Wheel());
-        $this->truck->setPart('wheel6', new Parts\Wheel());
+        $this->truck->setPart('wheel1', new Wheel());
+        $this->truck->setPart('wheel2', new Wheel());
+        $this->truck->setPart('wheel3', new Wheel());
+        $this->truck->setPart('wheel4', new Wheel());
+        $this->truck->setPart('wheel5', new Wheel());
+        $this->truck->setPart('wheel6', new Wheel());
     }
 
     public function createVehicle()
     {
-        $this->truck = new Parts\Truck();
+        $this->truck = new Truck();
     }
 
     public function getVehicle(): Vehicle

Creational/FactoryMethod/FileLogger.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Creational\FactoryMethod;
 
 class FileLogger implements Logger
 {
-    /**
-     * @var string
-     */
-    private $filePath;
+    private string $filePath;
 
     public function __construct(string $filePath)
     {

Creational/FactoryMethod/FileLoggerFactory.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Creational\FactoryMethod;
 
 class FileLoggerFactory implements LoggerFactory
 {
-    /**
-     * @var string
-     */
-    private $filePath;
+    private string $filePath;
 
     public function __construct(string $filePath)
     {

Creational/Multiton/Multiton.php

@@ -10,7 +10,7 @@ final class Multiton
     /**
      * @var Multiton[]
      */
-    private static $instances = [];
+    private static array $instances = [];
 
     /**
      * this is private to prevent from creating arbitrary instances

Creational/Pool/StringReverseWorker.php

@@ -2,16 +2,15 @@
 
 namespace DesignPatterns\Creational\Pool;
 
+use DateTime;
+
 class StringReverseWorker
 {
-    /**
-     * @var \DateTime
-     */
-    private $createdAt;
+    private DateTime $createdAt;
 
     public function __construct()
     {
-        $this->createdAt = new \DateTime();
+        $this->createdAt = new DateTime();
     }
 
     public function run(string $text)

Creational/Pool/WorkerPool.php

@@ -2,17 +2,19 @@
 
 namespace DesignPatterns\Creational\Pool;
 
-class WorkerPool implements \Countable
+use Countable;
+
+class WorkerPool implements Countable
 {
     /**
      * @var StringReverseWorker[]
      */
-    private $occupiedWorkers = [];
+    private array $occupiedWorkers = [];
 
     /**
      * @var StringReverseWorker[]
      */
-    private $freeWorkers = [];
+    private array $freeWorkers = [];
 
     public function get(): StringReverseWorker
     {

Creational/Prototype/BarBookPrototype.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Creational\Prototype;
 
 class BarBookPrototype extends BookPrototype
 {
-    /**
-     * @var string
-     */
-    protected $category = 'Bar';
+    protected string $category = 'Bar';
 
     public function __clone()
     {

Creational/Prototype/BookPrototype.php

@@ -4,15 +4,8 @@ namespace DesignPatterns\Creational\Prototype;
 
 abstract class BookPrototype
 {
-    /**
-     * @var string
-     */
-    protected $title;
-
-    /**
-     * @var string
-     */
-    protected $category;
+    protected string $title;
+    protected string $category;
 
     abstract public function __clone();
 
@@ -21,7 +14,7 @@ abstract class BookPrototype
         return $this->title;
     }
 
-    public function setTitle($title)
+    public function setTitle(string $title)
     {
         $this->title = $title;
     }

Creational/Prototype/FooBookPrototype.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Creational\Prototype;
 
 class FooBookPrototype extends BookPrototype
 {
-    /**
-     * @var string
-     */
-    protected $category = 'Foo';
+    protected string $category = 'Foo';
 
     public function __clone()
     {

Creational/Singleton/Singleton.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Creational\Singleton;
 
 final class Singleton
 {
-    /**
-     * @var Singleton
-     */
-    private static $instance;
+    private static ?Singleton $instance = null;
 
     /**
      * gets the instance via lazy initialization (created on first usage)

Creational/StaticFactory/StaticFactory.php

@@ -2,17 +2,14 @@
 
 namespace DesignPatterns\Creational\StaticFactory;
 
+use InvalidArgumentException;
+
 /**
  * Note1: Remember, static means global state which is evil because it can't be mocked for tests
  * Note2: Cannot be subclassed or mock-upped or have multiple different instances.
  */
 final class StaticFactory
 {
-    /**
-     * @param string $type
-     *
-     * @return Formatter
-     */
     public static function factory(string $type): Formatter
     {
         if ($type == 'number') {
@@ -21,6 +18,6 @@ final class StaticFactory
             return new FormatString();
         }
 
-        throw new \InvalidArgumentException('Unknown format given');
+        throw new InvalidArgumentException('Unknown format given');
     }
 }

Creational/StaticFactory/Tests/StaticFactoryTest.php

@@ -2,6 +2,7 @@
 
 namespace DesignPatterns\Creational\StaticFactory\Tests;
 
+use InvalidArgumentException;
 use DesignPatterns\Creational\StaticFactory\FormatNumber;
 use DesignPatterns\Creational\StaticFactory\FormatString;
 use DesignPatterns\Creational\StaticFactory\StaticFactory;
@@ -21,7 +22,7 @@ class StaticFactoryTest extends TestCase
 
     public function testException()
     {
-        $this->expectException(\InvalidArgumentException::class);
+        $this->expectException(InvalidArgumentException::class);
 
         StaticFactory::factory('object');
     }

More/EAV/Attribute.php

@@ -2,21 +2,16 @@
 
 namespace DesignPatterns\More\EAV;
 
+use SplObjectStorage;
+
 class Attribute
 {
-    /**
-     * @var \SplObjectStorage
-     */
-    private $values;
-
-    /**
-     * @var string
-     */
-    private $name;
+    private SplObjectStorage $values;
+    private string $name;
 
     public function __construct(string $name)
     {
-        $this->values = new \SplObjectStorage();
+        $this->values = new SplObjectStorage();
         $this->name = $name;
     }
 
@@ -25,10 +20,7 @@ class Attribute
         $this->values->attach($value);
     }
 
-    /**
-     * @return \SplObjectStorage
-     */
-    public function getValues(): \SplObjectStorage
+    public function getValues(): SplObjectStorage
     {
         return $this->values;
     }

More/EAV/Entity.php

@@ -14,7 +14,7 @@ class Entity
     /**
      * @var string
      */
-    private $name;
+    private string $name;
 
     /**
      * @param string $name
@@ -22,6 +22,7 @@ class Entity
      */
     public function __construct(string $name, $values)
     {
+        /** @var SplObjectStorage<Value,Value> values */
         $this->values = new SplObjectStorage();
         $this->name = $name;
 

More/EAV/Value.php

@@ -4,15 +4,8 @@ namespace DesignPatterns\More\EAV;
 
 class Value
 {
-    /**
-     * @var Attribute
-     */
-    private $attribute;
-
-    /**
-     * @var string
-     */
-    private $name;
+    private Attribute $attribute;
+    private string $name;
 
     public function __construct(Attribute $attribute, string $name)
     {

More/Repository/Domain/Post.php

@@ -4,25 +4,10 @@ namespace DesignPatterns\More\Repository\Domain;
 
 class Post
 {
-    /**
-     * @var PostId
-     */
-    private $id;
-
-    /**
-     * @var PostStatus
-     */
-    private $status;
-
-    /**
-     * @var string
-     */
-    private $title;
-
-    /**
-     * @var string
-     */
-    private $text;
+    private PostId $id;
+    private PostStatus $status;
+    private string $title;
+    private string $text;
 
     public static function draft(PostId $id, string $title, string $text): Post
     {
@@ -44,12 +29,6 @@ class Post
         );
     }
 
-    /**
-     * @param PostId $id
-     * @param PostStatus $status
-     * @param string $title
-     * @param string $text
-     */
     private function __construct(PostId $id, PostStatus $status, string $title, string $text)
     {
         $this->id = $id;

More/Repository/Domain/PostId.php

@@ -2,6 +2,8 @@
 
 namespace DesignPatterns\More\Repository\Domain;
 
+use InvalidArgumentException;
+
 /**
  * This is a perfect example of a value object that is identifiable by it's value alone and
  * is guaranteed to be valid each time an instance is created. Another important property of value objects
@@ -11,12 +13,9 @@ namespace DesignPatterns\More\Repository\Domain;
  */
 class PostId
 {
-    /**
-     * @var int
-     */
-    private $id;
+    private int $id;
 
-    public static function fromInt(int $id)
+    public static function fromInt(int $id): PostId
     {
         self::ensureIsValid($id);
 
@@ -36,7 +35,7 @@ class PostId
     private static function ensureIsValid(int $id)
     {
         if ($id <= 0) {
-            throw new \InvalidArgumentException('Invalid PostId given');
+            throw new InvalidArgumentException('Invalid PostId given');
         }
     }
 }

More/Repository/Domain/PostStatus.php

@@ -2,6 +2,8 @@
 
 namespace DesignPatterns\More\Repository\Domain;
 
+use InvalidArgumentException;
+
 /**
  * Like PostId, this is a value object which holds the value of the current status of a Post. It can be constructed
  * either from a string or int and is able to validate itself. An instance can then be converted back to int or string.
@@ -14,20 +16,13 @@ class PostStatus
     const STATE_DRAFT = 'draft';
     const STATE_PUBLISHED = 'published';
 
-    private static $validStates = [
+    private static array $validStates = [
         self::STATE_DRAFT_ID => self::STATE_DRAFT,
         self::STATE_PUBLISHED_ID => self::STATE_PUBLISHED,
     ];
 
-    /**
-     * @var int
-     */
-    private $id;
-
-    /**
-     * @var string
-     */
-    private $name;
+    private int $id;
+    private string $name;
 
     public static function fromInt(int $statusId)
     {
@@ -39,8 +34,13 @@ class PostStatus
     public static function fromString(string $status)
     {
         self::ensureIsValidName($status);
+        $state = array_search($status, self::$validStates);
 
-        return new self(array_search($status, self::$validStates), $status);
+        if ($state === false) {
+            throw new InvalidArgumentException('Invalid state given!');
+        }
+
+        return new self($state, $status);
     }
 
     private function __construct(int $id, string $name)
@@ -66,7 +66,7 @@ class PostStatus
     private static function ensureIsValidId(int $status)
     {
         if (!in_array($status, array_keys(self::$validStates), true)) {
-            throw new \InvalidArgumentException('Invalid status id given');
+            throw new InvalidArgumentException('Invalid status id given');
         }
     }
 
@@ -74,7 +74,7 @@ class PostStatus
     private static function ensureIsValidName(string $status)
     {
         if (!in_array($status, self::$validStates, true)) {
-            throw new \InvalidArgumentException('Invalid status name given');
+            throw new InvalidArgumentException('Invalid status name given');
         }
     }
 }

More/Repository/InMemoryPersistence.php

@@ -2,17 +2,12 @@
 
 namespace DesignPatterns\More\Repository;
 
+use OutOfBoundsException;
+
 class InMemoryPersistence implements Persistence
 {
-    /**
-     * @var array
-     */
-    private $data = [];
-
-    /**
-     * @var int
-     */
-    private $lastId = 0;
+    private array $data = [];
+    private int $lastId = 0;
 
     public function generateId(): int
     {
@@ -29,7 +24,7 @@ class InMemoryPersistence implements Persistence
     public function retrieve(int $id): array
     {
         if (!isset($this->data[$id])) {
-            throw new \OutOfBoundsException(sprintf('No data found for ID %d', $id));
+            throw new OutOfBoundsException(sprintf('No data found for ID %d', $id));
         }
 
         return $this->data[$id];
@@ -38,7 +33,7 @@ class InMemoryPersistence implements Persistence
     public function delete(int $id)
     {
         if (!isset($this->data[$id])) {
-            throw new \OutOfBoundsException(sprintf('No data found for ID %d', $id));
+            throw new OutOfBoundsException(sprintf('No data found for ID %d', $id));
         }
 
         unset($this->data[$id]);

More/Repository/PostRepository.php

@@ -2,6 +2,7 @@
 
 namespace DesignPatterns\More\Repository;
 
+use OutOfBoundsException;
 use DesignPatterns\More\Repository\Domain\Post;
 use DesignPatterns\More\Repository\Domain\PostId;
 
@@ -16,10 +17,7 @@ use DesignPatterns\More\Repository\Domain\PostId;
  */
 class PostRepository
 {
-    /**
-     * @var Persistence
-     */
-    private $persistence;
+    private Persistence $persistence;
 
     public function __construct(Persistence $persistence)
     {
@@ -35,8 +33,8 @@ class PostRepository
     {
         try {
             $arrayData = $this->persistence->retrieve($id->toInt());
-        } catch (\OutOfBoundsException $e) {
-            throw new \OutOfBoundsException(sprintf('Post with id %d does not exist', $id->toInt()), 0, $e);
+        } catch (OutOfBoundsException $e) {
+            throw new OutOfBoundsException(sprintf('Post with id %d does not exist', $id->toInt()), 0, $e);
         }
 
         return Post::fromState($arrayData);

More/Repository/Tests/PostRepositoryTest.php

@@ -2,6 +2,7 @@
 
 namespace DesignPatterns\More\Repository\Tests;
 
+use OutOfBoundsException;
 use DesignPatterns\More\Repository\Domain\PostId;
 use DesignPatterns\More\Repository\Domain\PostStatus;
 use DesignPatterns\More\Repository\InMemoryPersistence;
@@ -11,10 +12,7 @@ use PHPUnit\Framework\TestCase;
 
 class PostRepositoryTest extends TestCase
 {
-    /**
-     * @var PostRepository
-     */
-    private $repository;
+    private PostRepository $repository;
 
     protected function setUp(): void
     {
@@ -28,7 +26,7 @@ class PostRepositoryTest extends TestCase
 
     public function testThrowsExceptionWhenTryingToFindPostWhichDoesNotExist()
     {
-        $this->expectException(\OutOfBoundsException::class);
+        $this->expectException(OutOfBoundsException::class);
         $this->expectExceptionMessage('Post with id 42 does not exist');
 
         $this->repository->findById(PostId::fromInt(42));

More/ServiceLocator/ServiceLocator.php

@@ -2,17 +2,20 @@
 
 namespace DesignPatterns\More\ServiceLocator;
 
+use OutOfRangeException;
+use InvalidArgumentException;
+
 class ServiceLocator
 {
     /**
      * @var string[][]
      */
-    private $services = [];
+    private array $services = [];
 
     /**
      * @var Service[]
      */
-    private $instantiated = [];
+    private array $instantiated = [];
 
     public function addInstance(string $class, Service $service)
     {
@@ -51,11 +54,11 @@ class ServiceLocator
                 $object = new $class($args[0], $args[1], $args[2]);
                 break;
             default:
-                throw new \OutOfRangeException('Too many arguments given');
+                throw new OutOfRangeException('Too many arguments given');
         }
 
         if (!$object instanceof Service) {
-            throw new \InvalidArgumentException('Could not register service: is no instance of Service');
+            throw new InvalidArgumentException('Could not register service: is no instance of Service');
         }
 
         $this->instantiated[$class] = $object;

More/ServiceLocator/Tests/ServiceLocatorTest.php

@@ -8,10 +8,7 @@ use PHPUnit\Framework\TestCase;
 
 class ServiceLocatorTest extends TestCase
 {
-    /**
-     * @var ServiceLocator
-     */
-    private $serviceLocator;
+    private ServiceLocator $serviceLocator;
 
     public function setUp(): void
     {

Structural/Adapter/EBookAdapter.php

@@ -8,14 +8,8 @@ namespace DesignPatterns\Structural\Adapter;
  */
 class EBookAdapter implements Book
 {
-    /**
-     * @var EBook
-     */
-    protected $eBook;
+    protected EBook $eBook;
 
-    /**
-     * @param EBook $eBook
-     */
     public function __construct(EBook $eBook)
     {
         $this->eBook = $eBook;
@@ -37,8 +31,6 @@ class EBookAdapter implements Book
     /**
      * notice the adapted behavior here: EBook::getPage() will return two integers, but Book
      * supports only a current page getter, so we adapt the behavior here
-     *
-     * @return int
      */
     public function getPage(): int
     {

Structural/Adapter/Kindle.php

@@ -8,15 +8,8 @@ namespace DesignPatterns\Structural\Adapter;
  */
 class Kindle implements EBook
 {
-    /**
-     * @var int
-     */
-    private $page = 1;
-
-    /**
-     * @var int
-     */
-    private $totalPages = 100;
+    private int $page = 1;
+    private int $totalPages = 100;
 
     public function pressNext()
     {

Structural/Adapter/PaperBook.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Structural\Adapter;
 
 class PaperBook implements Book
 {
-    /**
-     * @var int
-     */
-    private $page;
+    private int $page;
 
     public function open()
     {

Structural/Bridge/Service.php

@@ -4,22 +4,13 @@ namespace DesignPatterns\Structural\Bridge;
 
 abstract class Service
 {
-    /**
-     * @var Formatter
-     */
-    protected $implementation;
+    protected Formatter $implementation;
 
-    /**
-     * @param Formatter $printer
-     */
     public function __construct(Formatter $printer)
     {
         $this->implementation = $printer;
     }
 
-    /**
-     * @param Formatter $printer
-     */
     public function setImplementation(Formatter $printer)
     {
         $this->implementation = $printer;

Structural/Composite/Form.php

@@ -11,15 +11,13 @@ class Form implements Renderable
     /**
      * @var Renderable[]
      */
-    private $elements;
+    private array $elements;
 
     /**
      * runs through all elements and calls render() on them, then returns the complete representation
      * of the form.
      *
      * from the outside, one will not see this and the form will act like a single object instance
-     *
-     * @return string
      */
     public function render(): string
     {
@@ -34,9 +32,6 @@ class Form implements Renderable
         return $formCode;
     }
 
-    /**
-     * @param Renderable $element
-     */
     public function addElement(Renderable $element)
     {
         $this->elements[] = $element;

Structural/Composite/Tests/CompositeTest.php

@@ -2,19 +2,21 @@
 
 namespace DesignPatterns\Structural\Composite\Tests;
 
-use DesignPatterns\Structural\Composite;
+use DesignPatterns\Structural\Composite\Form;
+use DesignPatterns\Structural\Composite\TextElement;
+use DesignPatterns\Structural\Composite\InputElement;
 use PHPUnit\Framework\TestCase;
 
 class CompositeTest extends TestCase
 {
     public function testRender()
     {
-        $form = new Composite\Form();
-        $form->addElement(new Composite\TextElement('Email:'));
-        $form->addElement(new Composite\InputElement());
-        $embed = new Composite\Form();
-        $embed->addElement(new Composite\TextElement('Password:'));
-        $embed->addElement(new Composite\InputElement());
+        $form = new Form();
+        $form->addElement(new TextElement('Email:'));
+        $form->addElement(new InputElement());
+        $embed = new Form();
+        $embed->addElement(new TextElement('Password:'));
+        $embed->addElement(new InputElement());
         $form->addElement($embed);
 
         // This is just an example, in a real world scenario it is important to remember that web browsers do not

Structural/Composite/TextElement.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Structural\Composite;
 
 class TextElement implements Renderable
 {
-    /**
-     * @var string
-     */
-    private $text;
+    private string $text;
 
     public function __construct(string $text)
     {

Structural/DataMapper/StorageAdapter.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Structural\DataMapper;
 
 class StorageAdapter
 {
-    /**
-     * @var array
-     */
-    private $data = [];
+    private array $data = [];
 
     public function __construct(array $data)
     {

Structural/DataMapper/Tests/DataMapperTest.php

@@ -2,6 +2,7 @@
 
 namespace DesignPatterns\Structural\DataMapper\Tests;
 
+use InvalidArgumentException;
 use DesignPatterns\Structural\DataMapper\StorageAdapter;
 use DesignPatterns\Structural\DataMapper\User;
 use DesignPatterns\Structural\DataMapper\UserMapper;
@@ -21,7 +22,7 @@ class DataMapperTest extends TestCase
 
     public function testWillNotMapInvalidData()
     {
-        $this->expectException(\InvalidArgumentException::class);
+        $this->expectException(InvalidArgumentException::class);
 
         $storage = new StorageAdapter([]);
         $mapper = new UserMapper($storage);

Structural/DataMapper/User.php

@@ -4,15 +4,8 @@ namespace DesignPatterns\Structural\DataMapper;
 
 class User
 {
-    /**
-     * @var string
-     */
-    private $username;
-
-    /**
-     * @var string
-     */
-    private $email;
+    private string $username;
+    private string $email;
 
     public static function fromState(array $state): User
     {
@@ -32,18 +25,12 @@ class User
         $this->email = $email;
     }
 
-    /**
-     * @return string
-     */
-    public function getUsername()
+    public function getUsername(): string
     {
         return $this->username;
     }
 
-    /**
-     * @return string
-     */
-    public function getEmail()
+    public function getEmail(): string
     {
         return $this->email;
     }

Structural/DataMapper/UserMapper.php

@@ -2,16 +2,12 @@
 
 namespace DesignPatterns\Structural\DataMapper;
 
+use InvalidArgumentException;
+
 class UserMapper
 {
-    /**
-     * @var StorageAdapter
-     */
-    private $adapter;
+    private StorageAdapter $adapter;
 
-    /**
-     * @param StorageAdapter $storage
-     */
     public function __construct(StorageAdapter $storage)
     {
         $this->adapter = $storage;
@@ -22,17 +18,13 @@ class UserMapper
      * in memory. Normally this kind of logic will be implemented using the Repository pattern.
      * However the important part is in mapRowToUser() below, that will create a business object from the
      * data fetched from storage
-     *
-     * @param int $id
-     *
-     * @return User
      */
     public function findById(int $id): User
     {
         $result = $this->adapter->find($id);
 
         if ($result === null) {
-            throw new \InvalidArgumentException("User #$id not found");
+            throw new InvalidArgumentException("User #$id not found");
         }
 
         return $this->mapRowToUser($result);

Structural/Decorator/BookingDecorator.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Structural\Decorator;
 
 abstract class BookingDecorator implements Booking
 {
-    /**
-     * @var Booking
-     */
-    protected $booking;
+    protected Booking $booking;
 
     public function __construct(Booking $booking)
     {

Structural/DependencyInjection/DatabaseConfiguration.php

@@ -4,25 +4,10 @@ namespace DesignPatterns\Structural\DependencyInjection;
 
 class DatabaseConfiguration
 {
-    /**
-     * @var string
-     */
-    private $host;
-
-    /**
-     * @var int
-     */
-    private $port;
-
-    /**
-     * @var string
-     */
-    private $username;
-
-    /**
-     * @var string
-     */
-    private $password;
+    private string $host;
+    private int $port;
+    private string $username;
+    private string $password;
 
     public function __construct(string $host, int $port, string $username, string $password)
     {

Structural/DependencyInjection/DatabaseConnection.php

@@ -4,14 +4,8 @@ namespace DesignPatterns\Structural\DependencyInjection;
 
 class DatabaseConnection
 {
-    /**
-     * @var DatabaseConfiguration
-     */
-    private $configuration;
+    private DatabaseConfiguration $configuration;
 
-    /**
-     * @param DatabaseConfiguration $config
-     */
     public function __construct(DatabaseConfiguration $config)
     {
         $this->configuration = $config;

Structural/Facade/Facade.php

@@ -4,20 +4,9 @@ namespace DesignPatterns\Structural\Facade;
 
 class Facade
 {
-    /**
-     * @var OperatingSystem
-     */
-    private $os;
+    private OperatingSystem $os;
+    private Bios $bios;
 
-    /**
-     * @var Bios
-     */
-    private $bios;
-
-    /**
-     * @param Bios $bios
-     * @param OperatingSystem   $os
-     */
     public function __construct(Bios $bios, OperatingSystem $os)
     {
         $this->bios = $bios;

Structural/FluentInterface/Sql.php

@@ -4,20 +4,9 @@ namespace DesignPatterns\Structural\FluentInterface;
 
 class Sql
 {
-    /**
-     * @var array
-     */
-    private $fields = [];
-
-    /**
-     * @var array
-     */
-    private $from = [];
-
-    /**
-     * @var array
-     */
-    private $where = [];
+    private array $fields = [];
+    private array $from = [];
+    private array $where = [];
 
     public function select(array $fields): Sql
     {

Structural/Flyweight/Character.php

@@ -11,10 +11,8 @@ class Character implements Text
     /**
      * Any state stored by the concrete flyweight must be independent of its context.
      * For flyweights representing characters, this is usually the corresponding character code.
-     *
-     * @var string
      */
-    private $name;
+    private string $name;
 
     public function __construct(string $name)
     {

Structural/Flyweight/Tests/FlyweightTest.php

@@ -7,9 +7,10 @@ use PHPUnit\Framework\TestCase;
 
 class FlyweightTest extends TestCase
 {
-    private $characters = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k',
+    private array $characters = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k',
         'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'];
-    private $fonts = ['Arial', 'Times New Roman', 'Verdana', 'Helvetica'];
+
+    private array $fonts = ['Arial', 'Times New Roman', 'Verdana', 'Helvetica'];
 
     public function testFlyweight()
     {

Structural/Flyweight/TextFactory.php

@@ -2,16 +2,18 @@
 
 namespace DesignPatterns\Structural\Flyweight;
 
+use Countable;
+
 /**
  * A factory manages shared flyweights. Clients should not instantiate them directly,
  * but let the factory take care of returning existing objects or creating new ones.
  */
-class TextFactory implements \Countable
+class TextFactory implements Countable
 {
     /**
      * @var Text[]
      */
-    private $charPool = [];
+    private array $charPool = [];
 
     public function get(string $name): Text
     {

Structural/Flyweight/Word.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Structural\Flyweight;
 
 class Word implements Text
 {
-    /**
-     * @var string
-     */
-    private $name;
+    private string $name;
 
     public function __construct(string $name)
     {

Structural/Proxy/BankAccountProxy.php

@@ -4,10 +4,7 @@ namespace DesignPatterns\Structural\Proxy;
 
 class BankAccountProxy extends HeavyBankAccount implements BankAccount
 {
-    /**
-     * @var int
-     */
-    private $balance;
+    private ?int $balance = null;
 
     public function getBalance(): int
     {

Structural/Proxy/HeavyBankAccount.php

@@ -7,7 +7,7 @@ class HeavyBankAccount implements BankAccount
     /**
      * @var int[]
      */
-    private $transactions = [];
+    private array $transactions = [];
 
     public function deposit(int $amount)
     {

Structural/Registry/Registry.php

@@ -2,6 +2,8 @@
 
 namespace DesignPatterns\Structural\Registry;
 
+use InvalidArgumentException;
+
 abstract class Registry
 {
     const LOGGER = 'logger';
@@ -12,19 +14,16 @@ abstract class Registry
      *
      * @var Service[]
      */
-    private static $services = [];
+    private static array $services = [];
 
-    /**
-     * @var array
-     */
-    private static $allowedKeys = [
+    private static array $allowedKeys = [
         self::LOGGER,
     ];
 
     public static function set(string $key, Service $value)
     {
         if (!in_array($key, self::$allowedKeys)) {
-            throw new \InvalidArgumentException('Invalid key given');
+            throw new InvalidArgumentException('Invalid key given');
         }
 
         self::$services[$key] = $value;
@@ -33,7 +32,7 @@ abstract class Registry
     public static function get(string $key): Service
     {
         if (!in_array($key, self::$allowedKeys) || !isset(self::$services[$key])) {
-            throw new \InvalidArgumentException('Invalid key given');
+            throw new InvalidArgumentException('Invalid key given');
         }
 
         return self::$services[$key];

Structural/Registry/Tests/RegistryTest.php

@@ -2,6 +2,7 @@
 
 namespace DesignPatterns\Structural\Registry\Tests;
 
+use InvalidArgumentException;
 use DesignPatterns\Structural\Registry\Registry;
 use DesignPatterns\Structural\Registry\Service;
 use PHPUnit\Framework\MockObject\MockObject;
@@ -9,7 +10,10 @@ use PHPUnit\Framework\TestCase;
 
 class RegistryTest extends TestCase
 {
-    private $service;
+    /**
+     * @var Service
+     */
+    private MockObject $service;
 
     protected function setUp(): void
     {
@@ -18,7 +22,6 @@ class RegistryTest extends TestCase
 
     public function testSetAndGetLogger()
     {
-        /** @noinspection PhpParamsInspection */
         Registry::set(Registry::LOGGER, $this->service);
 
         $this->assertSame($this->service, Registry::get(Registry::LOGGER));
@@ -26,7 +29,7 @@ class RegistryTest extends TestCase
 
     public function testThrowsExceptionWhenTryingToSetInvalidKey()
     {
-        $this->expectException(\InvalidArgumentException::class);
+        $this->expectException(InvalidArgumentException::class);
 
         Registry::set('foobar', $this->service);
     }
@@ -40,7 +43,7 @@ class RegistryTest extends TestCase
      */
     public function testThrowsExceptionWhenTryingToGetNotSetKey()
     {
-        $this->expectException(\InvalidArgumentException::class);
+        $this->expectException(InvalidArgumentException::class);
 
         Registry::get(Registry::LOGGER);
     }

composer.json

@@ -1,6 +1,7 @@
 {
     "name": "domnikl/design-patterns-php",
     "description": "Sample code for several design patterns in PHP",
+    "license": ["MIT"],
     "authors": [
         {
             "name": "Dominik Liebler",
@@ -9,7 +10,7 @@
     ],
     "minimum-stability": "stable",
     "require": {
-        "php": ">=7.2",
+        "php": ">=7.4",
         "psr/http-message": "^1.0",
         "ext-json": "*"
     },
@@ -18,11 +19,10 @@
         "squizlabs/php_codesniffer": "^3",
         "flyeralarm/php-code-validator": "^2.2",
         "vimeo/psalm": "^3.4",
-        "psalm/plugin-phpunit": "^0.7.0"
+        "psalm/plugin-phpunit": "^0.7.0",
+        "rector/rector": "^0.6.1"
     },
     "autoload": {
-        "psr-4": {
-            "DesignPatterns\\": ""
-        }
+        "classmap": ["Behavioral", "Creational", "Structural", "More"]
     }
 }