diff --git a/.travis.yml b/.travis.yml
index 2dda39e..7183b4b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,10 +1,10 @@
 language: php
 php:
-  - 7.0
-  - 7.1
-  - 7.2
+  - 8.0
+  - 8.1
+  - 8.2
 install:
-  - pecl install swoole-1.10.3
+  - pecl install swoole-4.8.13
   - composer update
 script:
   - vendor/bin/phpunit
diff --git a/composer.json b/composer.json
index 4bdf5a7..7f72881 100644
--- a/composer.json
+++ b/composer.json
@@ -14,16 +14,16 @@
     }
   ],
   "require": {
-    "php": ">=5.6.0",
+    "php": ">=7.4",
     "nikic/fast-route": "1.2.*",
-    "monolog/monolog": "~1.0",
+    "monolog/monolog": "^1.27",
     "psr/http-message": "^1.0",
-    "symfony/console": "^3.0 || ^4.0",
-    "psy/psysh": "^0.7.2 || ^0.8.0 || ^0.9.0",
-    "symfony/dotenv": "^3.3 || ^4.0"
+    "symfony/console": "^5.4",
+    "psy/psysh": "^0.11",
+    "symfony/dotenv": "^5.4"
   },
   "require-dev": {
-    "phpunit/phpunit": "~6.0"
+    "phpunit/phpunit": "^9.6"
   },
   "suggest": {
     "ext-swoole": "Run blink application under Swoole with visible performance improvements"
diff --git a/phpunit.xml b/phpunit.xml
index c0d7db1..0e278db 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit backupGlobals="false"
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         backupGlobals="false"
          backupStaticAttributes="false"
          bootstrap="tests/bootstrap.php"
          colors="true"
@@ -8,17 +9,17 @@
          convertWarningsToExceptions="true"
          processIsolation="false"
          stopOnFailure="false"
-         syntaxCheck="false">
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd">
+    <coverage>
+        <include>
+            <directory suffix=".php">app/</directory>
+        </include>
+    </coverage>
     <testsuites>
         <testsuite name="Application Test Suite">
             <directory>./tests/</directory>
         </testsuite>
     </testsuites>
-    <filter>
-        <whitelist>
-            <directory suffix=".php">app/</directory>
-        </whitelist>
-    </filter>
     <php>
     </php>
 </phpunit>
diff --git a/src/core/ServiceLocator.php b/src/core/ServiceLocator.php
index dfdef9e..edc75e6 100644
--- a/src/core/ServiceLocator.php
+++ b/src/core/ServiceLocator.php
@@ -3,6 +3,9 @@
 namespace blink\core;
 
 use blink\di\Container;
+use ReflectionClass;
+use ReflectionNamedType;
+use ReflectionParameter;
 
 /**
  * Class ServiceLocator
@@ -57,17 +60,28 @@ public function get($id)
     /**
      * Call the given callback or class method with dependency injection.
      *
-     * @param $callback
+     * @param callable $callback
      * @param array $arguments
      * @return mixed
      */
-    public function call($callback, $arguments = [])
+    public function call(callable $callback, array $arguments = [])
     {
-        $dependencies = $this->getMethodDependencies($callback, $arguments);
+        $dependencies = $this->getMethodDependencies($callback, array_values($arguments));
 
         return call_user_func_array($callback, $dependencies);
     }
 
+    protected function getParameterClass(ReflectionParameter $parameter): ?ReflectionClass
+    {
+        $type = $parameter->getType();
+
+        if ($type instanceof ReflectionNamedType) {
+            return new ReflectionClass($type->getName());
+        } else {
+            return null;
+        }
+    }
+
     protected function getMethodDependencies($callback, array $arguments = [])
     {
         $dependencies = $arguments;
@@ -76,7 +90,7 @@ protected function getMethodDependencies($callback, array $arguments = [])
         foreach ($parameters as $key => $parameter) {
             if ($parameter->isDefaultValueAvailable()) {
                 $dependencies[] = $parameter->getDefaultValue();
-            } elseif ($class = $parameter->getClass()) {
+            } elseif ($class = $this->getParameterClass($parameter)) {
                 $dependencies[] = $this->get($class->getName());
             } else {
                 throw new InvalidParamException('Missing required argument: ' . $parameter->getName());
diff --git a/src/di/Container.php b/src/di/Container.php
index fd13a19..aed406c 100644
--- a/src/di/Container.php
+++ b/src/di/Container.php
@@ -12,6 +12,7 @@
 use ReflectionClass;
 use blink\core\BaseObject;
 use blink\core\InvalidConfigException;
+use ReflectionNamedType;
 
 /**
  * Container implements a [dependency injection](http://en.wikipedia.org/wiki/Dependency_injection) container.
@@ -482,8 +483,8 @@ protected function getDependencies($class)
                 if ($param->isDefaultValueAvailable()) {
                     $dependencies[] = $param->getDefaultValue();
                 } else {
-                    $c = $param->getClass();
-                    $dependencies[] = Instance::of($c === null ? null : $c->getName());
+                    $c = $param->getType();
+                    $dependencies[] = Instance::of($c instanceof ReflectionNamedType ? $c->getName() : null);
                 }
             }
         }
diff --git a/src/http/CookieBag.php b/src/http/CookieBag.php
index 13f7d4a..357532f 100644
--- a/src/http/CookieBag.php
+++ b/src/http/CookieBag.php
@@ -10,6 +10,7 @@
 use ArrayIterator;
 use IteratorAggregate;
 use blink\core\BaseObject;
+use Traversable;
 
 /**
  * Class CookieBag
@@ -28,12 +29,12 @@ public function __construct(array $cookies = [], $config = [])
         parent::__construct($config);
     }
 
-    public function replace(array $cookies)
+    public function replace(array $cookies): void
     {
         $this->cookies = self::normalize($cookies);
     }
 
-    public static function normalize(array $cookies)
+    public static function normalize(array $cookies): array
     {
         foreach ($cookies as $name => $value) {
             if (!$value instanceof Cookie) {
@@ -50,7 +51,7 @@ public static function normalize(array $cookies)
      * @return Cookie[]
      * @since 0.3.0
      */
-    public function all()
+    public function all(): array
     {
         return $this->cookies;
     }
@@ -58,7 +59,7 @@ public function all()
     /**
      * Returns a cookie by name.
      *
-     * @param $name
+     * @param string $name
      * @return Cookie|null
      */
     public function get($name)
@@ -71,7 +72,7 @@ public function get($name)
      *
      * @param Cookie $cookie
      */
-    public function add(Cookie $cookie)
+    public function add(Cookie $cookie): void
     {
         $this->cookies[$cookie->name] = $cookie;
     }
@@ -79,10 +80,10 @@ public function add(Cookie $cookie)
     /**
      * Returns whether a cookie is exists.
      *
-     * @param $name
+     * @param string $name
      * @return bool
      */
-    public function has($name)
+    public function has(string $name): bool
     {
         return isset($this->cookies[$name]);
     }
@@ -90,19 +91,19 @@ public function has($name)
     /**
      * Remove a cookie by name.
      *
-     * @param $name
+     * @param string $name
      */
-    public function remove($name)
+    public function remove(string $name)
     {
         unset($this->cookies[$name]);
     }
 
-    public function count()
+    public function count(): int
     {
         return count($this->cookies);
     }
 
-    public function getIterator()
+    public function getIterator(): Traversable
     {
         return new ArrayIterator($this->cookies);
     }
diff --git a/src/http/FileBag.php b/src/http/FileBag.php
index 98c5ec7..7eb0b2b 100644
--- a/src/http/FileBag.php
+++ b/src/http/FileBag.php
@@ -6,6 +6,7 @@
 use ArrayIterator;
 use blink\core\BaseObject;
 use IteratorAggregate;
+use Traversable;
 
 /**
  * FileBag represents a set of uploaded files.
@@ -90,12 +91,12 @@ public function first($name)
         }
     }
 
-    public function count()
+    public function count(): int
     {
         return count($this->files);
     }
 
-    public function getIterator()
+    public function getIterator(): Traversable
     {
         return new ArrayIterator($this->files);
     }
diff --git a/src/http/HeaderBag.php b/src/http/HeaderBag.php
index 3b30844..26c970e 100644
--- a/src/http/HeaderBag.php
+++ b/src/http/HeaderBag.php
@@ -44,6 +44,7 @@ public function first($key, $default = null)
         return !empty($values) ? array_shift($values) : $default;
     }
 
+    #[\ReturnTypeWillChange]
     public function jsonSerialize()
     {
         return $this->all();
diff --git a/src/http/Request.php b/src/http/Request.php
index b502828..50c72e8 100644
--- a/src/http/Request.php
+++ b/src/http/Request.php
@@ -337,6 +337,8 @@ private function parseBody($body)
             $parsedBody = $this->parseQueryString($body);
         } elseif ($contentType === 'multipart/form-data') {
             // noop
+        } elseif ($contentType === 'application/xml' || $contentType === 'text/xml') {
+            $parsedBody = (array)simplexml_load_string($body, null, LIBXML_NOCDATA);
         } else {
             throw new NotSupportedException("The content type: '$contentType' does not supported");
         }
diff --git a/src/support/BagTrait.php b/src/support/BagTrait.php
index cb626d6..0e30890 100644
--- a/src/support/BagTrait.php
+++ b/src/support/BagTrait.php
@@ -3,6 +3,7 @@
 namespace blink\support;
 
 use ArrayIterator;
+use Traversable;
 
 trait BagTrait
 {
@@ -88,12 +89,12 @@ public function remove($key)
         unset($this->data[$this->transformKey($key)]);
     }
 
-    public function count()
+    public function count(): int
     {
         return count($this->data);
     }
 
-    public function getIterator()
+    public function getIterator(): Traversable
     {
         return new ArrayIterator($this->data);
     }
@@ -101,7 +102,8 @@ public function getIterator()
     /**
      * @inheritDoc
      */
-    public function offsetExists($offset)
+    #[\ReturnTypeWillChange]
+    public function offsetExists($offset): bool
     {
         return $this->has($offset);
     }
@@ -109,6 +111,7 @@ public function offsetExists($offset)
     /**
      * @inheritDoc
      */
+    #[\ReturnTypeWillChange]
     public function offsetGet($offset)
     {
         return $this->get($offset);
@@ -117,16 +120,17 @@ public function offsetGet($offset)
     /**
      * @inheritDoc
      */
-    public function offsetSet($offset, $value)
+    #[\ReturnTypeWillChange]
+    public function offsetSet($offset, $value): void
     {
-        return $this->set($offset, $value);
+        $this->set($offset, $value);
     }
 
     /**
      * @inheritDoc
      */
-    public function offsetUnset($offset)
+    public function offsetUnset($offset): void
     {
-        return $this->remove($offset);
+        $this->remove($offset);
     }
 }
diff --git a/src/testing/TestCase.php b/src/testing/TestCase.php
index 21b48aa..8836647 100644
--- a/src/testing/TestCase.php
+++ b/src/testing/TestCase.php
@@ -15,7 +15,7 @@ abstract class TestCase extends BaseTestCase
 
     abstract public function createApplication();
 
-    public function setUp()
+    public function setUp(): void
     {
         if (!$this->app) {
             $this->app = $this->createApplication()->bootstrapIfNeeded();
@@ -33,7 +33,7 @@ public function actor()
         return new RequestActor($this, $this->createApplication()->bootstrapIfNeeded());
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         if ($this->app) {
             $this->app->shutdown();
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 9a6e7af..c6e361c 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -1,3 +1,5 @@
 <?php
 
+ini_set('log_errors', 1);
+
 $loader = require __DIR__ . '/../vendor/autoload.php';
diff --git a/tests/log/LoggerTest.php b/tests/log/LoggerTest.php
index 070157e..61d06f8 100644
--- a/tests/log/LoggerTest.php
+++ b/tests/log/LoggerTest.php
@@ -15,14 +15,14 @@ class LoggerTest extends TestCase
 {
     protected $logFile;
 
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
 
         $this->logFile = __DIR__ . '/test.log';
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         if (file_exists($this->logFile)) {
             unlink($this->logFile);
@@ -47,7 +47,7 @@ protected function createLogger($logFile)
         ]);
     }
 
-    public function testLogBasic()
+    public function testLogBasic(): void
     {
         $log = $this->createLogger($this->logFile);
 
@@ -58,11 +58,11 @@ public function testLogBasic()
 
         $content = file_get_contents($this->logFile);
 
-        $this->assertContains('alert message', $content);
-        $this->assertNotContains('info message', $content);
+        $this->assertStringContainsString('alert message', $content);
+        $this->assertStringNotContainsString('info message', $content);
     }
 
-    public function testLogException()
+    public function testLogException(): void
     {
         $log = $this->createLogger($this->logFile);
 
diff --git a/tests/session/SessionTest.php b/tests/session/SessionTest.php
index 3604995..a4dac87 100644
--- a/tests/session/SessionTest.php
+++ b/tests/session/SessionTest.php
@@ -11,7 +11,7 @@ class SessionTest extends TestCase
 {
     private $sessionPath;
 
-    public function setUp()
+    public function setUp(): void
     {
         $this->sessionPath = __DIR__ . '/sessions';
         mkdir($this->sessionPath);
@@ -19,7 +19,7 @@ public function setUp()
         parent::setUp();
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         foreach (new \DirectoryIterator($this->sessionPath) as $file) {
             if (!$file->isDot()) {