Upgrade code to rely on PHP8 features

Author: e1himself

src/DependencyResolver.php

@@ -16,10 +16,7 @@
 
 final class DependencyResolver
 {
-    /**
-     * @var ContainerInterface
-     */
-    private $container;
+    private ContainerInterface $container;
 
     public function __construct(?ContainerInterface $container = null)
     {
@@ -28,14 +25,14 @@ public function __construct(?ContainerInterface $container = null)
 
     /**
      * @param string $className
-     * @return mixed|object|void
+     * @return mixed
      *
      * @throws InvalidArgumentException If class does not exist.
      * @throws ContainerExceptionInterface If error occurs while retrieving the existing entry from the container.
      * @throws ClassCannotBeInstantiated If class cannot be instantiated.
      * @throws CannotAutowireDependencyArgument If a dependency (of any nesting level) cannot be resolved.
      */
-    public function resolve(string $className)
+    public function resolve(string $className): mixed
     {
         if (! class_exists($className) && ! interface_exists($className)) {
             throw new InvalidArgumentException("`{$className}` is not a valid class name.");
@@ -51,11 +48,12 @@ public function resolve(string $className)
     /**
      * @param string $className
      * @param array $bindings
+     * @return mixed
      *
      * @throws ClassCannotBeInstantiated
      * @throws CannotAutowireDependencyArgument
      */
-    public function construct(string $className, array $bindings = [])
+    public function construct(string $className, array $bindings = []): mixed
     {
         if (! class_exists($className) && ! interface_exists($className)) {
             throw new InvalidArgumentException("`{$className}` is not a valid class name.");
@@ -84,7 +82,7 @@ public function construct(string $className, array $bindings = [])
      * @throws ArgumentCountError
      * @throws CannotAutowireArgument
      */
-    public function call(callable $callable, array $bindings = [])
+    public function call(callable $callable, array $bindings = []): mixed
     {
         $reflection = CallableReflection::fromCallable($callable);
 
@@ -130,7 +128,7 @@ private function resolveParameters(array $parameters, array $bindings = []): arr
      *
      * @throws CannotAutowireArgument
      */
-    private function resolveParameter(ParameterReflection $parameter)
+    private function resolveParameter(ParameterReflection $parameter): mixed
     {
         foreach ($parameter->getTypes() as $type) {
             if ($type->isClassRequirement() && $this->container->has($class = $type->getClassRequirement())) {

src/Exceptions/CannotAutowireArgument.php

@@ -9,7 +9,7 @@ final class CannotAutowireArgument extends DependencyResolutionException
     /**
      * @var string
      */
-    private $argumentName;
+    private string $argumentName;
 
     /**
      * @param string $argumentName

src/Exceptions/CannotAutowireDependencyArgument.php

@@ -9,12 +9,12 @@ final class CannotAutowireDependencyArgument extends DependencyResolutionExcepti
     /**
      * @var string
      */
-    private $dependencyName;
+    private string $dependencyName;
 
     /**
      * @var string
      */
-    private $argumentName;
+    private string $argumentName;
 
     /**
      * @param string $dependencyName

src/Exceptions/ClassCannotBeInstantiated.php

@@ -5,9 +5,9 @@
 final class ClassCannotBeInstantiated extends DependencyResolutionException
 {
     /**
-     * @var string
+     * @var class-string
      */
-    private $className;
+    private string $className;
 
     public function __construct(string $className)
     {
@@ -17,7 +17,7 @@ public function __construct(string $className)
     }
 
     /**
-     * @return string
+     * @return class-string
      */
     public function getClassName(): string
     {