diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 69415854f..9b48453b8 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -11,7 +11,7 @@ pull request for each branch. This allows me to review and pull in new features
 
 ## Style Guide
 
-All pull requests must adhere to the [PSR-2 standard](https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-2-coding-style-guide.md).
+All pull requests must adhere to the [PSR-12 standard](https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-12-extended-coding-style-guide.md).
 
 ## Unit Testing
 
diff --git a/Slim/App.php b/Slim/App.php
index 299c160d0..65825121d 100644
--- a/Slim/App.php
+++ b/Slim/App.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -27,6 +28,8 @@
 use Slim\Routing\RouteResolver;
 use Slim\Routing\RouteRunner;
 
+use function strtoupper;
+
 class App extends RouteCollectorProxy implements RequestHandlerInterface
 {
     /**
diff --git a/Slim/CallableResolver.php b/Slim/CallableResolver.php
index 71ed24dd0..91a1285cf 100644
--- a/Slim/CallableResolver.php
+++ b/Slim/CallableResolver.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -16,6 +17,15 @@
 use RuntimeException;
 use Slim\Interfaces\AdvancedCallableResolverInterface;
 
+use function class_exists;
+use function is_array;
+use function is_callable;
+use function is_object;
+use function is_string;
+use function json_encode;
+use function preg_match;
+use function sprintf;
+
 final class CallableResolver implements AdvancedCallableResolverInterface
 {
     /**
diff --git a/Slim/Error/AbstractErrorRenderer.php b/Slim/Error/AbstractErrorRenderer.php
index cebbfa867..1f608306b 100644
--- a/Slim/Error/AbstractErrorRenderer.php
+++ b/Slim/Error/AbstractErrorRenderer.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Error/Renderers/HtmlErrorRenderer.php b/Slim/Error/Renderers/HtmlErrorRenderer.php
index a1403e243..971a06b82 100644
--- a/Slim/Error/Renderers/HtmlErrorRenderer.php
+++ b/Slim/Error/Renderers/HtmlErrorRenderer.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -12,6 +13,10 @@
 use Slim\Error\AbstractErrorRenderer;
 use Throwable;
 
+use function get_class;
+use function htmlentities;
+use function sprintf;
+
 /**
  * Default Slim application HTML Error Renderer
  */
diff --git a/Slim/Error/Renderers/JsonErrorRenderer.php b/Slim/Error/Renderers/JsonErrorRenderer.php
index aaaf10bae..5ceb35921 100644
--- a/Slim/Error/Renderers/JsonErrorRenderer.php
+++ b/Slim/Error/Renderers/JsonErrorRenderer.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -12,6 +13,12 @@
 use Slim\Error\AbstractErrorRenderer;
 use Throwable;
 
+use function get_class;
+use function json_encode;
+
+use const JSON_PRETTY_PRINT;
+use const JSON_UNESCAPED_SLASHES;
+
 /**
  * Default Slim application JSON Error Renderer
  */
diff --git a/Slim/Error/Renderers/PlainTextErrorRenderer.php b/Slim/Error/Renderers/PlainTextErrorRenderer.php
index 303981d0c..0b961cd37 100644
--- a/Slim/Error/Renderers/PlainTextErrorRenderer.php
+++ b/Slim/Error/Renderers/PlainTextErrorRenderer.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -12,6 +13,10 @@
 use Slim\Error\AbstractErrorRenderer;
 use Throwable;
 
+use function get_class;
+use function htmlentities;
+use function sprintf;
+
 /**
  * Default Slim application Plain Text Error Renderer
  */
diff --git a/Slim/Error/Renderers/XmlErrorRenderer.php b/Slim/Error/Renderers/XmlErrorRenderer.php
index c09fa6bb3..80cd8f93a 100644
--- a/Slim/Error/Renderers/XmlErrorRenderer.php
+++ b/Slim/Error/Renderers/XmlErrorRenderer.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -12,6 +13,10 @@
 use Slim\Error\AbstractErrorRenderer;
 use Throwable;
 
+use function get_class;
+use function sprintf;
+use function str_replace;
+
 /**
  * Default Slim application XML Error Renderer
  */
diff --git a/Slim/Exception/HttpBadRequestException.php b/Slim/Exception/HttpBadRequestException.php
index 9a95cb3d0..a9b6f50c5 100644
--- a/Slim/Exception/HttpBadRequestException.php
+++ b/Slim/Exception/HttpBadRequestException.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Exception/HttpException.php b/Slim/Exception/HttpException.php
index 11ca34172..1fbbb4ac6 100644
--- a/Slim/Exception/HttpException.php
+++ b/Slim/Exception/HttpException.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Exception/HttpForbiddenException.php b/Slim/Exception/HttpForbiddenException.php
index fb45cbbaf..9a9141e34 100644
--- a/Slim/Exception/HttpForbiddenException.php
+++ b/Slim/Exception/HttpForbiddenException.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Exception/HttpInternalServerErrorException.php b/Slim/Exception/HttpInternalServerErrorException.php
index 254e5fec0..ae6b5f3f4 100644
--- a/Slim/Exception/HttpInternalServerErrorException.php
+++ b/Slim/Exception/HttpInternalServerErrorException.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Exception/HttpMethodNotAllowedException.php b/Slim/Exception/HttpMethodNotAllowedException.php
index 6a58fd05c..d6f8703c8 100644
--- a/Slim/Exception/HttpMethodNotAllowedException.php
+++ b/Slim/Exception/HttpMethodNotAllowedException.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -9,6 +10,8 @@
 
 namespace Slim\Exception;
 
+use function implode;
+
 class HttpMethodNotAllowedException extends HttpSpecializedException
 {
     /**
diff --git a/Slim/Exception/HttpNotFoundException.php b/Slim/Exception/HttpNotFoundException.php
index e2fca80bf..c4b7c9d30 100644
--- a/Slim/Exception/HttpNotFoundException.php
+++ b/Slim/Exception/HttpNotFoundException.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Exception/HttpNotImplementedException.php b/Slim/Exception/HttpNotImplementedException.php
index 1c0e58441..f8dcb3fb4 100644
--- a/Slim/Exception/HttpNotImplementedException.php
+++ b/Slim/Exception/HttpNotImplementedException.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Exception/HttpSpecializedException.php b/Slim/Exception/HttpSpecializedException.php
index b43c5c078..945e1ad44 100644
--- a/Slim/Exception/HttpSpecializedException.php
+++ b/Slim/Exception/HttpSpecializedException.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Exception/HttpUnauthorizedException.php b/Slim/Exception/HttpUnauthorizedException.php
index d70a933dc..5f143fe5d 100644
--- a/Slim/Exception/HttpUnauthorizedException.php
+++ b/Slim/Exception/HttpUnauthorizedException.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Factory/AppFactory.php b/Slim/Factory/AppFactory.php
index 7cb6357af..17bea3916 100644
--- a/Slim/Factory/AppFactory.php
+++ b/Slim/Factory/AppFactory.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -179,7 +180,8 @@ protected static function attemptResponseFactoryDecoration(
         ResponseFactoryInterface $responseFactory,
         StreamFactoryInterface $streamFactory
     ): ResponseFactoryInterface {
-        if (static::$slimHttpDecoratorsAutomaticDetectionEnabled
+        if (
+            static::$slimHttpDecoratorsAutomaticDetectionEnabled
             && SlimHttpPsr17Factory::isResponseFactoryAvailable()
         ) {
             return SlimHttpPsr17Factory::createDecoratedResponseFactory($responseFactory, $streamFactory);
diff --git a/Slim/Factory/Psr17/GuzzlePsr17Factory.php b/Slim/Factory/Psr17/GuzzlePsr17Factory.php
index 3d1331d48..8ac770291 100644
--- a/Slim/Factory/Psr17/GuzzlePsr17Factory.php
+++ b/Slim/Factory/Psr17/GuzzlePsr17Factory.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Factory/Psr17/LaminasDiactorosPsr17Factory.php b/Slim/Factory/Psr17/LaminasDiactorosPsr17Factory.php
new file mode 100644
index 000000000..097bc21b4
--- /dev/null
+++ b/Slim/Factory/Psr17/LaminasDiactorosPsr17Factory.php
@@ -0,0 +1,19 @@
+<?php
+
+/**
+ * Slim Framework (https://slimframework.com)
+ *
+ * @license https://github.com/slimphp/Slim/blob/4.x/LICENSE.md (MIT License)
+ */
+
+declare(strict_types=1);
+
+namespace Slim\Factory\Psr17;
+
+class LaminasDiactorosPsr17Factory extends Psr17Factory
+{
+    protected static $responseFactoryClass = 'Laminas\Diactoros\ResponseFactory';
+    protected static $streamFactoryClass = 'Laminas\Diactoros\StreamFactory';
+    protected static $serverRequestCreatorClass = 'Laminas\Diactoros\ServerRequestFactory';
+    protected static $serverRequestCreatorMethod = 'fromGlobals';
+}
diff --git a/Slim/Factory/Psr17/NyholmPsr17Factory.php b/Slim/Factory/Psr17/NyholmPsr17Factory.php
index 3a65fcc10..d3fe1307e 100644
--- a/Slim/Factory/Psr17/NyholmPsr17Factory.php
+++ b/Slim/Factory/Psr17/NyholmPsr17Factory.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Slim\Factory\Psr17;
@@ -21,7 +22,7 @@ public static function getServerRequestCreator(): ServerRequestCreatorInterface
          * Nyholm Psr17Factory implements all factories in one unified
          * factory which implements all of the PSR-17 factory interfaces
          */
-        $psr17Factory = new static::$responseFactoryClass;
+        $psr17Factory = new static::$responseFactoryClass();
 
         $serverRequestCreator = new static::$serverRequestCreatorClass(
             $psr17Factory,
diff --git a/Slim/Factory/Psr17/Psr17Factory.php b/Slim/Factory/Psr17/Psr17Factory.php
index 7b80ff99b..95f7d8bce 100644
--- a/Slim/Factory/Psr17/Psr17Factory.php
+++ b/Slim/Factory/Psr17/Psr17Factory.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -15,6 +16,9 @@
 use Slim\Interfaces\Psr17FactoryInterface;
 use Slim\Interfaces\ServerRequestCreatorInterface;
 
+use function class_exists;
+use function get_called_class;
+
 abstract class Psr17Factory implements Psr17FactoryInterface
 {
     /**
@@ -46,7 +50,7 @@ public static function getResponseFactory(): ResponseFactoryInterface
             throw new RuntimeException(get_called_class() . ' could not instantiate a response factory.');
         }
 
-        return new static::$responseFactoryClass;
+        return new static::$responseFactoryClass();
     }
 
     /**
@@ -58,7 +62,7 @@ public static function getStreamFactory(): StreamFactoryInterface
             throw new RuntimeException(get_called_class() . ' could not instantiate a stream factory.');
         }
 
-        return new static::$streamFactoryClass;
+        return new static::$streamFactoryClass();
     }
 
     /**
diff --git a/Slim/Factory/Psr17/Psr17FactoryProvider.php b/Slim/Factory/Psr17/Psr17FactoryProvider.php
index fe9596917..113ee432e 100644
--- a/Slim/Factory/Psr17/Psr17FactoryProvider.php
+++ b/Slim/Factory/Psr17/Psr17FactoryProvider.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -11,6 +12,8 @@
 
 use Slim\Interfaces\Psr17FactoryProviderInterface;
 
+use function array_unshift;
+
 class Psr17FactoryProvider implements Psr17FactoryProviderInterface
 {
     /**
@@ -19,6 +22,7 @@ class Psr17FactoryProvider implements Psr17FactoryProviderInterface
     protected static $factories = [
         SlimPsr17Factory::class,
         NyholmPsr17Factory::class,
+        LaminasDiactorosPsr17Factory::class,
         ZendDiactorosPsr17Factory::class,
         GuzzlePsr17Factory::class,
     ];
diff --git a/Slim/Factory/Psr17/ServerRequestCreator.php b/Slim/Factory/Psr17/ServerRequestCreator.php
index abe1ffd63..b4fe54640 100644
--- a/Slim/Factory/Psr17/ServerRequestCreator.php
+++ b/Slim/Factory/Psr17/ServerRequestCreator.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Factory/Psr17/SlimHttpPsr17Factory.php b/Slim/Factory/Psr17/SlimHttpPsr17Factory.php
index 59691ee82..193b8668b 100644
--- a/Slim/Factory/Psr17/SlimHttpPsr17Factory.php
+++ b/Slim/Factory/Psr17/SlimHttpPsr17Factory.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Factory/Psr17/SlimHttpServerRequestCreator.php b/Slim/Factory/Psr17/SlimHttpServerRequestCreator.php
index 171984703..cac5f22e0 100644
--- a/Slim/Factory/Psr17/SlimHttpServerRequestCreator.php
+++ b/Slim/Factory/Psr17/SlimHttpServerRequestCreator.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -13,6 +14,8 @@
 use RuntimeException;
 use Slim\Interfaces\ServerRequestCreatorInterface;
 
+use function class_exists;
+
 class SlimHttpServerRequestCreator implements ServerRequestCreatorInterface
 {
     /**
diff --git a/Slim/Factory/Psr17/SlimPsr17Factory.php b/Slim/Factory/Psr17/SlimPsr17Factory.php
index 825abf022..8de6de945 100644
--- a/Slim/Factory/Psr17/SlimPsr17Factory.php
+++ b/Slim/Factory/Psr17/SlimPsr17Factory.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Factory/Psr17/ZendDiactorosPsr17Factory.php b/Slim/Factory/Psr17/ZendDiactorosPsr17Factory.php
index 17cabad85..779e761e7 100644
--- a/Slim/Factory/Psr17/ZendDiactorosPsr17Factory.php
+++ b/Slim/Factory/Psr17/ZendDiactorosPsr17Factory.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Factory/ServerRequestCreatorFactory.php b/Slim/Factory/ServerRequestCreatorFactory.php
index d21ff9cca..fb75d30bf 100644
--- a/Slim/Factory/ServerRequestCreatorFactory.php
+++ b/Slim/Factory/ServerRequestCreatorFactory.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -76,7 +77,8 @@ public static function determineServerRequestCreator(): ServerRequestCreatorInte
     protected static function attemptServerRequestCreatorDecoration(
         ServerRequestCreatorInterface $serverRequestCreator
     ): ServerRequestCreatorInterface {
-        if (static::$slimHttpDecoratorsAutomaticDetectionEnabled
+        if (
+            static::$slimHttpDecoratorsAutomaticDetectionEnabled
             && SlimHttpServerRequestCreator::isServerRequestDecoratorAvailable()
         ) {
             return new SlimHttpServerRequestCreator($serverRequestCreator);
diff --git a/Slim/Handlers/ErrorHandler.php b/Slim/Handlers/ErrorHandler.php
index 1d00defdd..a92d12f5f 100644
--- a/Slim/Handlers/ErrorHandler.php
+++ b/Slim/Handlers/ErrorHandler.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -24,6 +25,18 @@
 use Slim\Interfaces\ErrorRendererInterface;
 use Throwable;
 
+use function array_intersect;
+use function array_key_exists;
+use function array_keys;
+use function call_user_func;
+use function count;
+use function current;
+use function error_log;
+use function explode;
+use function implode;
+use function next;
+use function preg_match;
+
 /**
  * Default Slim application error handler
  *
diff --git a/Slim/Handlers/Strategies/RequestHandler.php b/Slim/Handlers/Strategies/RequestHandler.php
index 31fa1bee4..dd118172a 100644
--- a/Slim/Handlers/Strategies/RequestHandler.php
+++ b/Slim/Handlers/Strategies/RequestHandler.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Handlers/Strategies/RequestResponse.php b/Slim/Handlers/Strategies/RequestResponse.php
index 7b8a02cb3..9de0d9f56 100644
--- a/Slim/Handlers/Strategies/RequestResponse.php
+++ b/Slim/Handlers/Strategies/RequestResponse.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Handlers/Strategies/RequestResponseArgs.php b/Slim/Handlers/Strategies/RequestResponseArgs.php
index 2201e2a04..0cff7459b 100644
--- a/Slim/Handlers/Strategies/RequestResponseArgs.php
+++ b/Slim/Handlers/Strategies/RequestResponseArgs.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -13,6 +14,8 @@
 use Psr\Http\Message\ServerRequestInterface;
 use Slim\Interfaces\InvocationStrategyInterface;
 
+use function array_values;
+
 /**
  * Route callback strategy with route parameters as individual arguments.
  */
diff --git a/Slim/Interfaces/AdvancedCallableResolverInterface.php b/Slim/Interfaces/AdvancedCallableResolverInterface.php
index 89684fc7c..c9d290768 100644
--- a/Slim/Interfaces/AdvancedCallableResolverInterface.php
+++ b/Slim/Interfaces/AdvancedCallableResolverInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Interfaces/CallableResolverInterface.php b/Slim/Interfaces/CallableResolverInterface.php
index a16e53f7f..3e960b967 100644
--- a/Slim/Interfaces/CallableResolverInterface.php
+++ b/Slim/Interfaces/CallableResolverInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Interfaces/DispatcherInterface.php b/Slim/Interfaces/DispatcherInterface.php
index 7fc41ba3f..de50588e4 100644
--- a/Slim/Interfaces/DispatcherInterface.php
+++ b/Slim/Interfaces/DispatcherInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Interfaces/ErrorHandlerInterface.php b/Slim/Interfaces/ErrorHandlerInterface.php
index b6679cabf..0cdbb1136 100644
--- a/Slim/Interfaces/ErrorHandlerInterface.php
+++ b/Slim/Interfaces/ErrorHandlerInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Interfaces/ErrorRendererInterface.php b/Slim/Interfaces/ErrorRendererInterface.php
index 1ec0f4da9..90d480be6 100644
--- a/Slim/Interfaces/ErrorRendererInterface.php
+++ b/Slim/Interfaces/ErrorRendererInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Interfaces/InvocationStrategyInterface.php b/Slim/Interfaces/InvocationStrategyInterface.php
index b155061ab..d7be7ca4f 100644
--- a/Slim/Interfaces/InvocationStrategyInterface.php
+++ b/Slim/Interfaces/InvocationStrategyInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Interfaces/MiddlewareDispatcherInterface.php b/Slim/Interfaces/MiddlewareDispatcherInterface.php
index 78eff1485..60c93976a 100644
--- a/Slim/Interfaces/MiddlewareDispatcherInterface.php
+++ b/Slim/Interfaces/MiddlewareDispatcherInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Interfaces/Psr17FactoryInterface.php b/Slim/Interfaces/Psr17FactoryInterface.php
index 4ce10fa01..dcc1c76d5 100644
--- a/Slim/Interfaces/Psr17FactoryInterface.php
+++ b/Slim/Interfaces/Psr17FactoryInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Interfaces/Psr17FactoryProviderInterface.php b/Slim/Interfaces/Psr17FactoryProviderInterface.php
index aa7b57c05..58d224f28 100644
--- a/Slim/Interfaces/Psr17FactoryProviderInterface.php
+++ b/Slim/Interfaces/Psr17FactoryProviderInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Interfaces/RequestHandlerInvocationStrategyInterface.php b/Slim/Interfaces/RequestHandlerInvocationStrategyInterface.php
index 7a128cfe8..ec98fc6de 100644
--- a/Slim/Interfaces/RequestHandlerInvocationStrategyInterface.php
+++ b/Slim/Interfaces/RequestHandlerInvocationStrategyInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Interfaces/RouteCollectorInterface.php b/Slim/Interfaces/RouteCollectorInterface.php
index ebb035977..959bcd356 100644
--- a/Slim/Interfaces/RouteCollectorInterface.php
+++ b/Slim/Interfaces/RouteCollectorInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Interfaces/RouteCollectorProxyInterface.php b/Slim/Interfaces/RouteCollectorProxyInterface.php
index 8e871a6ea..f0514e1c0 100644
--- a/Slim/Interfaces/RouteCollectorProxyInterface.php
+++ b/Slim/Interfaces/RouteCollectorProxyInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Interfaces/RouteGroupInterface.php b/Slim/Interfaces/RouteGroupInterface.php
index d03583c54..b2b57482e 100644
--- a/Slim/Interfaces/RouteGroupInterface.php
+++ b/Slim/Interfaces/RouteGroupInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Interfaces/RouteInterface.php b/Slim/Interfaces/RouteInterface.php
index 394b13b64..018680fde 100644
--- a/Slim/Interfaces/RouteInterface.php
+++ b/Slim/Interfaces/RouteInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Interfaces/RouteParserInterface.php b/Slim/Interfaces/RouteParserInterface.php
index 1c45fd558..23b717e13 100644
--- a/Slim/Interfaces/RouteParserInterface.php
+++ b/Slim/Interfaces/RouteParserInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Interfaces/RouteResolverInterface.php b/Slim/Interfaces/RouteResolverInterface.php
index aaefd5fbe..bda15fd46 100644
--- a/Slim/Interfaces/RouteResolverInterface.php
+++ b/Slim/Interfaces/RouteResolverInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Slim\Interfaces;
diff --git a/Slim/Interfaces/ServerRequestCreatorInterface.php b/Slim/Interfaces/ServerRequestCreatorInterface.php
index 26e3ac6a3..37ffb01af 100644
--- a/Slim/Interfaces/ServerRequestCreatorInterface.php
+++ b/Slim/Interfaces/ServerRequestCreatorInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Middleware/BodyParsingMiddleware.php b/Slim/Middleware/BodyParsingMiddleware.php
index b7d0944ee..1a121430d 100644
--- a/Slim/Middleware/BodyParsingMiddleware.php
+++ b/Slim/Middleware/BodyParsingMiddleware.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -15,6 +16,21 @@
 use Psr\Http\Server\RequestHandlerInterface;
 use RuntimeException;
 
+use function count;
+use function explode;
+use function is_array;
+use function is_null;
+use function is_object;
+use function is_string;
+use function json_decode;
+use function libxml_clear_errors;
+use function libxml_disable_entity_loader;
+use function libxml_use_internal_errors;
+use function parse_str;
+use function simplexml_load_string;
+use function strtolower;
+use function trim;
+
 class BodyParsingMiddleware implements MiddlewareInterface
 {
     /**
diff --git a/Slim/Middleware/ContentLengthMiddleware.php b/Slim/Middleware/ContentLengthMiddleware.php
index b57cc1dc2..b74239806 100644
--- a/Slim/Middleware/ContentLengthMiddleware.php
+++ b/Slim/Middleware/ContentLengthMiddleware.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Middleware/MethodOverrideMiddleware.php b/Slim/Middleware/MethodOverrideMiddleware.php
index 26ef24e2e..39388aa5a 100644
--- a/Slim/Middleware/MethodOverrideMiddleware.php
+++ b/Slim/Middleware/MethodOverrideMiddleware.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -14,6 +15,9 @@
 use Psr\Http\Server\MiddlewareInterface;
 use Psr\Http\Server\RequestHandlerInterface;
 
+use function is_array;
+use function strtoupper;
+
 class MethodOverrideMiddleware implements MiddlewareInterface
 {
     /**
diff --git a/Slim/Middleware/OutputBufferingMiddleware.php b/Slim/Middleware/OutputBufferingMiddleware.php
index 71dfd057a..198ee8f35 100644
--- a/Slim/Middleware/OutputBufferingMiddleware.php
+++ b/Slim/Middleware/OutputBufferingMiddleware.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -17,6 +18,11 @@
 use Psr\Http\Server\RequestHandlerInterface;
 use Throwable;
 
+use function in_array;
+use function ob_end_clean;
+use function ob_get_clean;
+use function ob_start;
+
 class OutputBufferingMiddleware implements MiddlewareInterface
 {
     public const APPEND = 'append';
diff --git a/Slim/Middleware/RoutingMiddleware.php b/Slim/Middleware/RoutingMiddleware.php
index b217f7324..4c24e3bc8 100644
--- a/Slim/Middleware/RoutingMiddleware.php
+++ b/Slim/Middleware/RoutingMiddleware.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/MiddlewareDispatcher.php b/Slim/MiddlewareDispatcher.php
index 39029ae39..08b1c536b 100644
--- a/Slim/MiddlewareDispatcher.php
+++ b/Slim/MiddlewareDispatcher.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -20,6 +21,13 @@
 use Slim\Interfaces\CallableResolverInterface;
 use Slim\Interfaces\MiddlewareDispatcherInterface;
 
+use function class_exists;
+use function function_exists;
+use function is_callable;
+use function is_string;
+use function preg_match;
+use function sprintf;
+
 class MiddlewareDispatcher implements MiddlewareDispatcherInterface
 {
     /**
@@ -116,7 +124,7 @@ public function add($middleware): MiddlewareDispatcherInterface
     public function addMiddleware(MiddlewareInterface $middleware): MiddlewareDispatcherInterface
     {
         $next = $this->tip;
-        $this->tip = new class($middleware, $next) implements RequestHandlerInterface
+        $this->tip = new class ($middleware, $next) implements RequestHandlerInterface
         {
             private $middleware;
             private $next;
@@ -149,7 +157,7 @@ public function handle(ServerRequestInterface $request): ResponseInterface
     public function addDeferred(string $middleware): self
     {
         $next = $this->tip;
-        $this->tip = new class(
+        $this->tip = new class (
             $middleware,
             $next,
             $this->container,
@@ -259,7 +267,7 @@ public function addCallable(callable $middleware): self
             $middleware = $middleware->bindTo($this->container);
         }
 
-        $this->tip = new class($middleware, $next) implements RequestHandlerInterface
+        $this->tip = new class ($middleware, $next) implements RequestHandlerInterface
         {
             private $middleware;
             private $next;
diff --git a/Slim/ResponseEmitter.php b/Slim/ResponseEmitter.php
index 6f0f159b3..51294f4f6 100644
--- a/Slim/ResponseEmitter.php
+++ b/Slim/ResponseEmitter.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -11,6 +12,17 @@
 
 use Psr\Http\Message\ResponseInterface;
 
+use function connection_status;
+use function header;
+use function headers_sent;
+use function in_array;
+use function min;
+use function sprintf;
+use function strlen;
+use function strtolower;
+
+use const CONNECTION_NORMAL;
+
 class ResponseEmitter
 {
     /**
diff --git a/Slim/Routing/Dispatcher.php b/Slim/Routing/Dispatcher.php
index 7c9d51e9c..070af2071 100644
--- a/Slim/Routing/Dispatcher.php
+++ b/Slim/Routing/Dispatcher.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Slim\Routing;
diff --git a/Slim/Routing/FastRouteDispatcher.php b/Slim/Routing/FastRouteDispatcher.php
index 126282fb3..522af8545 100644
--- a/Slim/Routing/FastRouteDispatcher.php
+++ b/Slim/Routing/FastRouteDispatcher.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Routing/Route.php b/Slim/Routing/Route.php
index cb60a3721..47badf823 100644
--- a/Slim/Routing/Route.php
+++ b/Slim/Routing/Route.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -25,6 +26,13 @@
 use Slim\Interfaces\RouteInterface;
 use Slim\MiddlewareDispatcher;
 
+use function array_key_exists;
+use function array_replace;
+use function array_reverse;
+use function class_implements;
+use function in_array;
+use function is_array;
+
 class Route implements RouteInterface, RequestHandlerInterface
 {
     /**
@@ -361,7 +369,8 @@ public function handle(ServerRequestInterface $request): ResponseInterface
         }
         $strategy = $this->invocationStrategy;
 
-        if (is_array($callable)
+        if (
+            is_array($callable)
             && $callable[0] instanceof RequestHandlerInterface
             && !in_array(RequestHandlerInvocationStrategyInterface::class, class_implements($strategy))
         ) {
diff --git a/Slim/Routing/RouteCollector.php b/Slim/Routing/RouteCollector.php
index 154dcc18e..0508c9400 100644
--- a/Slim/Routing/RouteCollector.php
+++ b/Slim/Routing/RouteCollector.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -20,6 +21,13 @@
 use Slim\Interfaces\RouteInterface;
 use Slim\Interfaces\RouteParserInterface;
 
+use function array_pop;
+use function dirname;
+use function file_exists;
+use function sprintf;
+use function is_readable;
+use function is_writable;
+
 /**
  * RouteCollector is used to collect routes and route groups
  * as well as generate paths and URLs relative to its environment
diff --git a/Slim/Routing/RouteCollectorProxy.php b/Slim/Routing/RouteCollectorProxy.php
index a5cdd4e50..293740e33 100644
--- a/Slim/Routing/RouteCollectorProxy.php
+++ b/Slim/Routing/RouteCollectorProxy.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Routing/RouteContext.php b/Slim/Routing/RouteContext.php
index 219fb1539..40b989214 100644
--- a/Slim/Routing/RouteContext.php
+++ b/Slim/Routing/RouteContext.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Routing/RouteGroup.php b/Slim/Routing/RouteGroup.php
index 4801afe76..c73d5ffa7 100644
--- a/Slim/Routing/RouteGroup.php
+++ b/Slim/Routing/RouteGroup.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Routing/RouteParser.php b/Slim/Routing/RouteParser.php
index 216175c6c..a2b79277b 100644
--- a/Slim/Routing/RouteParser.php
+++ b/Slim/Routing/RouteParser.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -15,6 +16,12 @@
 use Slim\Interfaces\RouteCollectorInterface;
 use Slim\Interfaces\RouteParserInterface;
 
+use function array_key_exists;
+use function array_reverse;
+use function http_build_query;
+use function implode;
+use function is_string;
+
 class RouteParser implements RouteParserInterface
 {
     /**
diff --git a/Slim/Routing/RouteResolver.php b/Slim/Routing/RouteResolver.php
index ac5f014cc..30f07d5fd 100644
--- a/Slim/Routing/RouteResolver.php
+++ b/Slim/Routing/RouteResolver.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -15,6 +16,8 @@
 use Slim\Interfaces\RouteInterface;
 use Slim\Interfaces\RouteResolverInterface;
 
+use function rawurldecode;
+
 /**
  * RouteResolver instantiates the FastRoute dispatcher
  * and computes the routing results of a given URI and request method
diff --git a/Slim/Routing/RouteRunner.php b/Slim/Routing/RouteRunner.php
index d6796ade7..50c11f29c 100644
--- a/Slim/Routing/RouteRunner.php
+++ b/Slim/Routing/RouteRunner.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/Slim/Routing/RoutingResults.php b/Slim/Routing/RoutingResults.php
index 06cf6d8a5..b67abe28b 100644
--- a/Slim/Routing/RoutingResults.php
+++ b/Slim/Routing/RoutingResults.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -11,6 +12,8 @@
 
 use Slim\Interfaces\DispatcherInterface;
 
+use function rawurldecode;
+
 class RoutingResults
 {
     public const NOT_FOUND = 0;
diff --git a/composer.json b/composer.json
index d3c990104..23389111a 100644
--- a/composer.json
+++ b/composer.json
@@ -33,9 +33,9 @@
         }
     ],
     "require": {
+        "php": "^7.2",
         "ext-json": "*",
         "nikic/fast-route": "^1.3",
-        "php": "^7.2",
         "psr/container": "^1.0",
         "psr/http-factory": "^1.0",
         "psr/http-message": "^1.0",
@@ -44,17 +44,18 @@
     },
     "require-dev": {
         "ext-simplexml": "*",
+        "adriansuter/php-autoload-override": "^1.0",
         "guzzlehttp/psr7": "^1.5",
         "http-interop/http-factory-guzzle": "^1.0",
+        "laminas/laminas-diactoros": "^2.1",
         "nyholm/psr7": "^1.1",
         "nyholm/psr7-server": "^0.3.0",
-        "phpunit/phpunit": "^8.5",
         "phpspec/prophecy": "^1.10",
         "phpstan/phpstan": "^0.11.5",
+        "phpunit/phpunit": "^8.5",
         "slim/http": "^0.7",
         "slim/psr7": "^0.3",
-        "squizlabs/php_codesniffer": "^3.4.2",
-        "laminas/laminas-diactoros": "^2.1"
+        "squizlabs/php_codesniffer": "^3.5"
     },
     "autoload": {
         "psr-4": {
@@ -81,5 +82,8 @@
         "ext-xml": "Needed to support XML format in BodyParsingMiddleware",
         "slim/psr7": "Slim PSR-7 implementation. See https://www.slimframework.com/docs/v4/start/installation.html for more information.",
         "php-di/php-di": "PHP-DI is the recommended container library to be used with Slim"
+    },
+    "config": {
+        "sort-packages": true
     }
 }
diff --git a/phpcs.xml b/phpcs.xml
index e84ded80f..0c1eddae1 100644
--- a/phpcs.xml
+++ b/phpcs.xml
@@ -8,7 +8,7 @@
     <arg name="colors"/>
 
     <!-- inherit rules from: -->
-    <rule ref="PSR2"/>
+    <rule ref="PSR12"/>
     <rule ref="Generic.Arrays.DisallowLongArraySyntax"/>
 
     <!-- Paths to check -->
diff --git a/tests/AppTest.php b/tests/AppTest.php
index 2d94bad2f..63f3ee126 100644
--- a/tests/AppTest.php
+++ b/tests/AppTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -18,6 +19,8 @@
 use Psr\Http\Message\UriInterface;
 use Psr\Http\Server\MiddlewareInterface;
 use Psr\Http\Server\RequestHandlerInterface;
+use ReflectionClass;
+use ReflectionProperty;
 use RuntimeException;
 use Slim\App;
 use Slim\CallableResolver;
@@ -39,6 +42,15 @@
 use Slim\Tests\Mocks\MockAction;
 use stdClass;
 
+use function array_key_exists;
+use function array_shift;
+use function count;
+use function ini_set;
+use function json_encode;
+use function strtolower;
+use function sys_get_temp_dir;
+use function tempnam;
+
 class AppTest extends TestCase
 {
     public static function setupBeforeClass(): void
@@ -689,17 +701,17 @@ public function testAddRoutingMiddleware()
         $routingMiddleware = $app->addRoutingMiddleware();
 
         // Check that the routing middleware really has been added to the tip of the app middleware stack.
-        $middlewareDispatcherProperty = new \ReflectionProperty(App::class, 'middlewareDispatcher');
+        $middlewareDispatcherProperty = new ReflectionProperty(App::class, 'middlewareDispatcher');
         $middlewareDispatcherProperty->setAccessible(true);
         /** @var MiddlewareDispatcher $middlewareDispatcher */
         $middlewareDispatcher = $middlewareDispatcherProperty->getValue($app);
 
-        $tipProperty = new \ReflectionProperty(MiddlewareDispatcher::class, 'tip');
+        $tipProperty = new ReflectionProperty(MiddlewareDispatcher::class, 'tip');
         $tipProperty->setAccessible(true);
         /** @var RequestHandlerInterface $tip */
         $tip = $tipProperty->getValue($middlewareDispatcher);
 
-        $reflection = new \ReflectionClass($tip);
+        $reflection = new ReflectionClass($tip);
         $middlewareProperty = $reflection->getProperty('middleware');
         $middlewareProperty->setAccessible(true);
 
@@ -719,17 +731,17 @@ public function testAddErrorMiddleware()
         $errorMiddleware = $app->addErrorMiddleware(true, true, true);
 
         // Check that the error middleware really has been added to the tip of the app middleware stack.
-        $middlewareDispatcherProperty = new \ReflectionProperty(App::class, 'middlewareDispatcher');
+        $middlewareDispatcherProperty = new ReflectionProperty(App::class, 'middlewareDispatcher');
         $middlewareDispatcherProperty->setAccessible(true);
         /** @var MiddlewareDispatcher $middlewareDispatcher */
         $middlewareDispatcher = $middlewareDispatcherProperty->getValue($app);
 
-        $tipProperty = new \ReflectionProperty(MiddlewareDispatcher::class, 'tip');
+        $tipProperty = new ReflectionProperty(MiddlewareDispatcher::class, 'tip');
         $tipProperty->setAccessible(true);
         /** @var RequestHandlerInterface $tip */
         $tip = $tipProperty->getValue($middlewareDispatcher);
 
-        $reflection = new \ReflectionClass($tip);
+        $reflection = new ReflectionClass($tip);
         $middlewareProperty = $reflection->getProperty('middleware');
         $middlewareProperty->setAccessible(true);
 
@@ -749,17 +761,17 @@ public function testAddBodyParsingMiddleware()
         $bodyParsingMiddleware = $app->addBodyParsingMiddleware();
 
         // Check that the body parsing middleware really has been added to the tip of the app middleware stack.
-        $middlewareDispatcherProperty = new \ReflectionProperty(App::class, 'middlewareDispatcher');
+        $middlewareDispatcherProperty = new ReflectionProperty(App::class, 'middlewareDispatcher');
         $middlewareDispatcherProperty->setAccessible(true);
         /** @var MiddlewareDispatcher $middlewareDispatcher */
         $middlewareDispatcher = $middlewareDispatcherProperty->getValue($app);
 
-        $tipProperty = new \ReflectionProperty(MiddlewareDispatcher::class, 'tip');
+        $tipProperty = new ReflectionProperty(MiddlewareDispatcher::class, 'tip');
         $tipProperty->setAccessible(true);
         /** @var RequestHandlerInterface $tip */
         $tip = $tipProperty->getValue($middlewareDispatcher);
 
-        $reflection = new \ReflectionClass($tip);
+        $reflection = new ReflectionClass($tip);
         $middlewareProperty = $reflection->getProperty('middleware');
         $middlewareProperty->setAccessible(true);
 
diff --git a/tests/Assets/HeaderStack.php b/tests/Assets/HeaderStack.php
index ba93dd26f..82664df55 100644
--- a/tests/Assets/HeaderStack.php
+++ b/tests/Assets/HeaderStack.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * This is a direct copy of zend-diactoros/test/TestAsset/Functions.php and is used to override
  * header() and headers_sent() so we can test that they do the right thing.
@@ -11,6 +12,9 @@
 
 namespace Slim\Tests\Assets;
 
+use function explode;
+use function trim;
+
 /**
  * Zend Framework (http://framework.zend.com/)
  *
diff --git a/tests/Assets/PhpFunctionOverrides.php b/tests/Assets/PhpFunctionOverrides.php
index dd1749d37..c13b8cb69 100644
--- a/tests/Assets/PhpFunctionOverrides.php
+++ b/tests/Assets/PhpFunctionOverrides.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Override PHP namespaced functions into the Slim\App namespace.
  *
diff --git a/tests/Assets/PhpRoutingFunctionOverrides.php b/tests/Assets/PhpRoutingFunctionOverrides.php
index 6a6f66de5..40f441933 100644
--- a/tests/Assets/PhpRoutingFunctionOverrides.php
+++ b/tests/Assets/PhpRoutingFunctionOverrides.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -9,6 +10,8 @@
 
 namespace Slim\Routing;
 
+use function stripos;
+
 /**
  * Is a file descriptor writable
  *
diff --git a/tests/CallableResolverTest.php b/tests/CallableResolverTest.php
index d5da3d775..727164c48 100644
--- a/tests/CallableResolverTest.php
+++ b/tests/CallableResolverTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -88,9 +89,9 @@ public function testClosureContainer()
     public function testFunctionName()
     {
         $resolver = new CallableResolver(); // No container injected
-        $callable = $resolver->resolve(__NAMESPACE__.'\testAdvancedCallable');
-        $callableRoute = $resolver->resolveRoute(__NAMESPACE__.'\testAdvancedCallable');
-        $callableMiddleware = $resolver->resolveMiddleware(__NAMESPACE__.'\testAdvancedCallable');
+        $callable = $resolver->resolve(__NAMESPACE__ . '\testAdvancedCallable');
+        $callableRoute = $resolver->resolveRoute(__NAMESPACE__ . '\testAdvancedCallable');
+        $callableMiddleware = $resolver->resolveMiddleware(__NAMESPACE__ . '\testAdvancedCallable');
 
         $this->assertEquals(true, $callable());
         $this->assertEquals(true, $callableRoute());
@@ -315,9 +316,9 @@ public function testMiddlewareObjPsrRequestHandlerClassInContainer()
     public function testResolutionToAPsrRequestHandlerClassWithCustomMethod()
     {
         $resolver = new CallableResolver(); // No container injected
-        $callable = $resolver->resolve(RequestHandlerTest::class.':custom');
-        $callableRoute = $resolver->resolveRoute(RequestHandlerTest::class.':custom');
-        $callableMiddleware = $resolver->resolveMiddleware(RequestHandlerTest::class.':custom');
+        $callable = $resolver->resolve(RequestHandlerTest::class . ':custom');
+        $callableRoute = $resolver->resolveRoute(RequestHandlerTest::class . ':custom');
+        $callableMiddleware = $resolver->resolveMiddleware(RequestHandlerTest::class . ':custom');
 
         $this->assertIsArray($callable);
         $this->assertInstanceOf(RequestHandlerTest::class, $callable[0]);
diff --git a/tests/Error/AbstractErrorRendererTest.php b/tests/Error/AbstractErrorRendererTest.php
index 434558609..ff2f98f2d 100644
--- a/tests/Error/AbstractErrorRendererTest.php
+++ b/tests/Error/AbstractErrorRendererTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -20,6 +21,10 @@
 use Slim\Tests\TestCase;
 use stdClass;
 
+use function json_decode;
+use function json_encode;
+use function simplexml_load_string;
+
 class AbstractErrorRendererTest extends TestCase
 {
     public function testHTMLErrorRendererDisplaysErrorDetails()
diff --git a/tests/Exception/HttpExceptionTest.php b/tests/Exception/HttpExceptionTest.php
index 48281fdca..3879581a5 100644
--- a/tests/Exception/HttpExceptionTest.php
+++ b/tests/Exception/HttpExceptionTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Exception/HttpUnauthorizedExceptionTest.php b/tests/Exception/HttpUnauthorizedExceptionTest.php
index 7a55a75b5..b57b839a7 100644
--- a/tests/Exception/HttpUnauthorizedExceptionTest.php
+++ b/tests/Exception/HttpUnauthorizedExceptionTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Factory/AppFactoryTest.php b/tests/Factory/AppFactoryTest.php
index c0abe741f..922b09e2d 100644
--- a/tests/Factory/AppFactoryTest.php
+++ b/tests/Factory/AppFactoryTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -10,6 +11,7 @@
 namespace Slim\Tests\Factory;
 
 use Http\Factory\Guzzle\ResponseFactory as GuzzleResponseFactory;
+use Laminas\Diactoros\ResponseFactory as LaminasDiactorosResponseFactory;
 use Nyholm\Psr7\Factory\Psr17Factory;
 use Psr\Container\ContainerInterface;
 use Psr\Http\Message\ResponseFactoryInterface;
@@ -19,6 +21,7 @@
 use RuntimeException;
 use Slim\Factory\AppFactory;
 use Slim\Factory\Psr17\GuzzlePsr17Factory;
+use Slim\Factory\Psr17\LaminasDiactorosPsr17Factory;
 use Slim\Factory\Psr17\NyholmPsr17Factory;
 use Slim\Factory\Psr17\Psr17FactoryProvider;
 use Slim\Factory\Psr17\SlimPsr17Factory;
@@ -44,6 +47,7 @@ public function provideImplementations()
             [SlimPsr17Factory::class, SlimResponseFactory::class],
             [NyholmPsr17Factory::class, Psr17Factory::class],
             [GuzzlePsr17Factory::class, GuzzleResponseFactory::class],
+            [LaminasDiactorosPsr17Factory::class, LaminasDiactorosResponseFactory::class],
             [ZendDiactorosPsr17Factory::class, ZendDiactorosResponseFactory::class],
         ];
     }
diff --git a/tests/Factory/Psr17/Psr17FactoryProviderTest.php b/tests/Factory/Psr17/Psr17FactoryProviderTest.php
index 2326b081f..bb5e8a768 100644
--- a/tests/Factory/Psr17/Psr17FactoryProviderTest.php
+++ b/tests/Factory/Psr17/Psr17FactoryProviderTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Factory/Psr17/Psr17FactoryTest.php b/tests/Factory/Psr17/Psr17FactoryTest.php
index 9126a4509..da5821705 100644
--- a/tests/Factory/Psr17/Psr17FactoryTest.php
+++ b/tests/Factory/Psr17/Psr17FactoryTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Factory/Psr17/SlimHttpServerRequestCreatorTest.php b/tests/Factory/Psr17/SlimHttpServerRequestCreatorTest.php
index 2a0408857..eea5f36fb 100644
--- a/tests/Factory/Psr17/SlimHttpServerRequestCreatorTest.php
+++ b/tests/Factory/Psr17/SlimHttpServerRequestCreatorTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Factory/ServerRequestCreatorFactoryTest.php b/tests/Factory/ServerRequestCreatorFactoryTest.php
index e5f6a9601..f6c4a6996 100644
--- a/tests/Factory/ServerRequestCreatorFactoryTest.php
+++ b/tests/Factory/ServerRequestCreatorFactoryTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -10,10 +11,12 @@
 namespace Slim\Tests\Factory;
 
 use GuzzleHttp\Psr7\ServerRequest as GuzzleServerRequest;
+use Laminas\Diactoros\ServerRequest as LaminasDiactorosServerRequest;
 use Nyholm\Psr7\ServerRequest as NyholmServerRequest;
 use Psr\Http\Message\ServerRequestInterface;
 use RuntimeException;
 use Slim\Factory\Psr17\GuzzlePsr17Factory;
+use Slim\Factory\Psr17\LaminasDiactorosPsr17Factory;
 use Slim\Factory\Psr17\NyholmPsr17Factory;
 use Slim\Factory\Psr17\Psr17FactoryProvider;
 use Slim\Factory\Psr17\SlimHttpServerRequestCreator;
@@ -24,7 +27,7 @@
 use Slim\Interfaces\ServerRequestCreatorInterface;
 use Slim\Psr7\Request as SlimServerRequest;
 use Slim\Tests\TestCase;
-use Zend\Diactoros\ServerRequest as ZendServerRequest;
+use Zend\Diactoros\ServerRequest as ZendDiactorosServerRequest;
 
 class ServerRequestCreatorFactoryTest extends TestCase
 {
@@ -34,7 +37,8 @@ public function provideImplementations()
             [SlimPsr17Factory::class, SlimServerRequest::class],
             [NyholmPsr17Factory::class, NyholmServerRequest::class],
             [GuzzlePsr17Factory::class, GuzzleServerRequest::class],
-            [ZendDiactorosPsr17Factory::class, ZendServerRequest::class],
+            [LaminasDiactorosPsr17Factory::class, LaminasDiactorosServerRequest::class],
+            [ZendDiactorosPsr17Factory::class, ZendDiactorosServerRequest::class],
         ];
     }
 
diff --git a/tests/Handlers/ErrorHandlerTest.php b/tests/Handlers/ErrorHandlerTest.php
index 3c5d8392a..44251229c 100644
--- a/tests/Handlers/ErrorHandlerTest.php
+++ b/tests/Handlers/ErrorHandlerTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Middleware/BodyParsingMiddlewareTest.php b/tests/Middleware/BodyParsingMiddlewareTest.php
index 5633355bb..b4d5cc25c 100644
--- a/tests/Middleware/BodyParsingMiddlewareTest.php
+++ b/tests/Middleware/BodyParsingMiddlewareTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -16,16 +17,19 @@
 use Slim\Middleware\BodyParsingMiddleware;
 use Slim\Tests\TestCase;
 
+use function is_string;
+use function simplexml_load_string;
+
 class BodyParsingMiddlewareTest extends TestCase
 {
     /**
      * Create a request handler that simply assigns the $request that it receives to a public property
      * of the returned response, so that we can then inspect that request.
      */
-    protected function createRequestHandler() : RequestHandlerInterface
+    protected function createRequestHandler(): RequestHandlerInterface
     {
         $response = $this->createResponse();
-        return new class($response) implements RequestHandlerInterface {
+        return new class ($response) implements RequestHandlerInterface {
             private $response;
 
             public function __construct(ResponseInterface $response)
diff --git a/tests/Middleware/ContentLengthMiddlewareTest.php b/tests/Middleware/ContentLengthMiddlewareTest.php
index 8fdc00101..79a1c7766 100644
--- a/tests/Middleware/ContentLengthMiddlewareTest.php
+++ b/tests/Middleware/ContentLengthMiddlewareTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Middleware/MethodOverrideMiddlewareTest.php b/tests/Middleware/MethodOverrideMiddlewareTest.php
index f088baa80..55e65a55f 100644
--- a/tests/Middleware/MethodOverrideMiddlewareTest.php
+++ b/tests/Middleware/MethodOverrideMiddlewareTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Middleware/OutputBufferingMiddlewareTest.php b/tests/Middleware/OutputBufferingMiddlewareTest.php
index 1790a4dbf..10c0f4d8b 100644
--- a/tests/Middleware/OutputBufferingMiddlewareTest.php
+++ b/tests/Middleware/OutputBufferingMiddlewareTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -16,6 +17,8 @@
 use Slim\Middleware\OutputBufferingMiddleware;
 use Slim\Tests\TestCase;
 
+use function ob_get_contents;
+
 class OutputBufferingMiddlewareTest extends TestCase
 {
     public function testStyleDefaultValid()
diff --git a/tests/Middleware/RoutingMiddlewareTest.php b/tests/Middleware/RoutingMiddlewareTest.php
index 330ed410d..8c5debf63 100644
--- a/tests/Middleware/RoutingMiddlewareTest.php
+++ b/tests/Middleware/RoutingMiddlewareTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/MiddlewareDispatcherTest.php b/tests/MiddlewareDispatcherTest.php
index 6c295ea11..8ffcf0534 100644
--- a/tests/MiddlewareDispatcherTest.php
+++ b/tests/MiddlewareDispatcherTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -459,7 +460,7 @@ public function testThrowsExceptionForDeferredNonMiddlewareInterfaceClasses()
         /** @var RequestHandlerInterface $kernel */
         $kernel = $kernelProphecy->reveal();
         $dispatcher = $this->createMiddlewareDispatcher($kernel, null);
-        $dispatcher->addDeferred(\stdClass::class);
+        $dispatcher->addDeferred(stdClass::class);
         $dispatcher->handle($requestProphecy->reveal());
 
         $kernelProphecy->handle(Argument::type(ServerRequestInterface::class))->shouldNotHaveBeenCalled();
diff --git a/tests/Mocks/CallableTest.php b/tests/Mocks/CallableTest.php
index ad2b880bb..19b271927 100644
--- a/tests/Mocks/CallableTest.php
+++ b/tests/Mocks/CallableTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Mocks/InvocationStrategyTest.php b/tests/Mocks/InvocationStrategyTest.php
index 764782fb9..2fe30bb9e 100644
--- a/tests/Mocks/InvocationStrategyTest.php
+++ b/tests/Mocks/InvocationStrategyTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Mocks/InvokableTest.php b/tests/Mocks/InvokableTest.php
index 8ac5e6aad..0b88fff7c 100644
--- a/tests/Mocks/InvokableTest.php
+++ b/tests/Mocks/InvokableTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Mocks/MiddlewareTest.php b/tests/Mocks/MiddlewareTest.php
index 0a10f66d2..475af3260 100644
--- a/tests/Mocks/MiddlewareTest.php
+++ b/tests/Mocks/MiddlewareTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Mocks/MockAction.php b/tests/Mocks/MockAction.php
index 789ba5709..09dda712b 100644
--- a/tests/Mocks/MockAction.php
+++ b/tests/Mocks/MockAction.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -11,6 +12,10 @@
 
 use InvalidArgumentException;
 
+use function compact;
+use function count;
+use function json_encode;
+
 class MockAction
 {
     public function __call($name, array $arguments)
diff --git a/tests/Mocks/MockCustomException.php b/tests/Mocks/MockCustomException.php
index e2decae34..9d1f966d7 100644
--- a/tests/Mocks/MockCustomException.php
+++ b/tests/Mocks/MockCustomException.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Mocks/MockCustomRequestHandlerInvocationStrategy.php b/tests/Mocks/MockCustomRequestHandlerInvocationStrategy.php
index 9fdac9e29..5761a9adf 100644
--- a/tests/Mocks/MockCustomRequestHandlerInvocationStrategy.php
+++ b/tests/Mocks/MockCustomRequestHandlerInvocationStrategy.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Mocks/MockMiddlewareSlimCallable.php b/tests/Mocks/MockMiddlewareSlimCallable.php
index ca165ba25..50de90196 100644
--- a/tests/Mocks/MockMiddlewareSlimCallable.php
+++ b/tests/Mocks/MockMiddlewareSlimCallable.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Mocks/MockMiddlewareWithConstructor.php b/tests/Mocks/MockMiddlewareWithConstructor.php
index 89592cb2e..f49ea195b 100644
--- a/tests/Mocks/MockMiddlewareWithConstructor.php
+++ b/tests/Mocks/MockMiddlewareWithConstructor.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Mocks/MockMiddlewareWithoutConstructor.php b/tests/Mocks/MockMiddlewareWithoutConstructor.php
index 2617b3dc3..6fb9adac8 100644
--- a/tests/Mocks/MockMiddlewareWithoutConstructor.php
+++ b/tests/Mocks/MockMiddlewareWithoutConstructor.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Mocks/MockMiddlewareWithoutInterface.php b/tests/Mocks/MockMiddlewareWithoutInterface.php
index 74d504668..11eaea4a2 100644
--- a/tests/Mocks/MockMiddlewareWithoutInterface.php
+++ b/tests/Mocks/MockMiddlewareWithoutInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Mocks/MockPsr17Factory.php b/tests/Mocks/MockPsr17Factory.php
index 8b42271cd..20d6784fd 100644
--- a/tests/Mocks/MockPsr17Factory.php
+++ b/tests/Mocks/MockPsr17Factory.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Mocks/MockPsr17FactoryWithoutStreamFactory.php b/tests/Mocks/MockPsr17FactoryWithoutStreamFactory.php
index 12e632953..0e572c27f 100644
--- a/tests/Mocks/MockPsr17FactoryWithoutStreamFactory.php
+++ b/tests/Mocks/MockPsr17FactoryWithoutStreamFactory.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Mocks/MockRequestHandler.php b/tests/Mocks/MockRequestHandler.php
index f96f4c155..38bc21522 100644
--- a/tests/Mocks/MockRequestHandler.php
+++ b/tests/Mocks/MockRequestHandler.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Mocks/MockSequenceMiddleware.php b/tests/Mocks/MockSequenceMiddleware.php
index 9019b2073..500d0b930 100644
--- a/tests/Mocks/MockSequenceMiddleware.php
+++ b/tests/Mocks/MockSequenceMiddleware.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Mocks/MockStream.php b/tests/Mocks/MockStream.php
index 9a2317d3a..996b94a25 100644
--- a/tests/Mocks/MockStream.php
+++ b/tests/Mocks/MockStream.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -12,6 +13,25 @@
 use Exception;
 use InvalidArgumentException;
 use Psr\Http\Message\StreamInterface;
+use RuntimeException;
+
+use function clearstatcache;
+use function fclose;
+use function feof;
+use function fopen;
+use function fread;
+use function fseek;
+use function fstat;
+use function ftell;
+use function fwrite;
+use function gettype;
+use function is_resource;
+use function is_string;
+use function stream_get_contents;
+use function stream_get_meta_data;
+use function var_export;
+
+use const SEEK_SET;
 
 class MockStream implements StreamInterface
 {
@@ -55,15 +75,15 @@ class MockStream implements StreamInterface
      */
     public function __construct($body = '')
     {
-        if (\is_string($body)) {
-            $resource = \fopen('php://temp', 'rw+');
-            \fwrite($resource, $body);
+        if (is_string($body)) {
+            $resource = fopen('php://temp', 'rw+');
+            fwrite($resource, $body);
             $body = $resource;
         }
 
-        if ('resource' === \gettype($body)) {
+        if ('resource' === gettype($body)) {
             $this->stream = $body;
-            $meta = \stream_get_meta_data($this->stream);
+            $meta = stream_get_meta_data($this->stream);
             $this->seekable = $meta['seekable'];
             $this->readable = isset(self::$readWriteHash['read'][$meta['mode']]);
             $this->writable = isset(self::$readWriteHash['write'][$meta['mode']]);
@@ -99,8 +119,8 @@ public function __toString(): string
     public function close(): void
     {
         if (isset($this->stream)) {
-            if (\is_resource($this->stream)) {
-                \fclose($this->stream);
+            if (is_resource($this->stream)) {
+                fclose($this->stream);
             }
             $this->detach();
         }
@@ -132,10 +152,10 @@ public function getSize(): ?int
 
         // Clear the stat cache if the stream has a URI
         if ($this->uri) {
-            \clearstatcache(true, $this->uri);
+            clearstatcache(true, $this->uri);
         }
 
-        $stats = \fstat($this->stream);
+        $stats = fstat($this->stream);
         if (isset($stats['size'])) {
             $this->size = $stats['size'];
 
@@ -147,8 +167,8 @@ public function getSize(): ?int
 
     public function tell(): int
     {
-        if (false === $result = \ftell($this->stream)) {
-            throw new \RuntimeException('Unable to determine stream position');
+        if (false === $result = ftell($this->stream)) {
+            throw new RuntimeException('Unable to determine stream position');
         }
 
         return $result;
@@ -156,7 +176,7 @@ public function tell(): int
 
     public function eof(): bool
     {
-        return !$this->stream || \feof($this->stream);
+        return !$this->stream || feof($this->stream);
     }
 
     public function isSeekable(): bool
@@ -164,14 +184,14 @@ public function isSeekable(): bool
         return $this->seekable;
     }
 
-    public function seek($offset, $whence = \SEEK_SET): void
+    public function seek($offset, $whence = SEEK_SET): void
     {
         if (!$this->seekable) {
-            throw new \RuntimeException('Stream is not seekable');
-        } elseif (\fseek($this->stream, $offset, $whence) === -1) {
-            throw new \RuntimeException(
+            throw new RuntimeException('Stream is not seekable');
+        } elseif (fseek($this->stream, $offset, $whence) === -1) {
+            throw new RuntimeException(
                 'Unable to seek to stream position '
-                .$offset.' with whence '.\var_export($whence, true)
+                . $offset . ' with whence ' . var_export($whence, true)
             );
         }
     }
@@ -189,14 +209,14 @@ public function isWritable(): bool
     public function write($string): int
     {
         if (!$this->writable) {
-            throw new \RuntimeException('Cannot write to a non-writable stream');
+            throw new RuntimeException('Cannot write to a non-writable stream');
         }
 
         // We can't know the size after writing anything
         $this->size = null;
 
-        if (false === $result = \fwrite($this->stream, $string)) {
-            throw new \RuntimeException('Unable to write to stream');
+        if (false === $result = fwrite($this->stream, $string)) {
+            throw new RuntimeException('Unable to write to stream');
         }
 
         return $result;
@@ -210,20 +230,20 @@ public function isReadable(): bool
     public function read($length): string
     {
         if (!$this->readable) {
-            throw new \RuntimeException('Cannot read from non-readable stream');
+            throw new RuntimeException('Cannot read from non-readable stream');
         }
 
-        return \fread($this->stream, $length);
+        return fread($this->stream, $length);
     }
 
     public function getContents(): string
     {
         if (!isset($this->stream)) {
-            throw new \RuntimeException('Unable to read stream contents');
+            throw new RuntimeException('Unable to read stream contents');
         }
 
-        if (false === $contents = \stream_get_contents($this->stream)) {
-            throw new \RuntimeException('Unable to read stream contents');
+        if (false === $contents = stream_get_contents($this->stream)) {
+            throw new RuntimeException('Unable to read stream contents');
         }
 
         return $contents;
@@ -234,10 +254,10 @@ public function getMetadata($key = null)
         if (!isset($this->stream)) {
             return $key ? null : [];
         } elseif (null === $key) {
-            return \stream_get_meta_data($this->stream);
+            return stream_get_meta_data($this->stream);
         }
 
-        $meta = \stream_get_meta_data($this->stream);
+        $meta = stream_get_meta_data($this->stream);
 
         return isset($meta[$key]) ? $meta[$key] : null;
     }
diff --git a/tests/Mocks/RequestHandlerTest.php b/tests/Mocks/RequestHandlerTest.php
index 93ee33375..7025c876e 100644
--- a/tests/Mocks/RequestHandlerTest.php
+++ b/tests/Mocks/RequestHandlerTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -14,6 +15,8 @@
 use Psr\Http\Server\RequestHandlerInterface;
 use Slim\Tests\Providers\PSR7ObjectProvider;
 
+use function debug_backtrace;
+
 class RequestHandlerTest implements RequestHandlerInterface
 {
     public static $CalledCount = 0;
diff --git a/tests/Mocks/SlowPokeStream.php b/tests/Mocks/SlowPokeStream.php
index feaa78c24..b5547b295 100644
--- a/tests/Mocks/SlowPokeStream.php
+++ b/tests/Mocks/SlowPokeStream.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -12,10 +13,16 @@
 use Exception;
 use Psr\Http\Message\StreamInterface;
 
+use function min;
+use function str_repeat;
+use function usleep;
+
+use const SEEK_SET;
+
 class SlowPokeStream implements StreamInterface
 {
-    const CHUNK_SIZE = 1;
-    const SIZE = 500;
+    public const CHUNK_SIZE = 1;
+    public const SIZE = 500;
 
     /**
      * @var int
@@ -82,7 +89,7 @@ public function isWritable()
 
     public function read($length)
     {
-        \usleep(1);
+        usleep(1);
         $size = min($this->amountToRead, self::CHUNK_SIZE, $length);
         $this->amountToRead -= $size;
         return str_repeat('.', $size);
diff --git a/tests/Mocks/SmallChunksStream.php b/tests/Mocks/SmallChunksStream.php
index 510364e6b..b136c7f37 100644
--- a/tests/Mocks/SmallChunksStream.php
+++ b/tests/Mocks/SmallChunksStream.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -12,10 +13,15 @@
 use Exception;
 use Psr\Http\Message\StreamInterface;
 
+use function min;
+use function str_repeat;
+
+use const SEEK_SET;
+
 class SmallChunksStream implements StreamInterface
 {
-    const CHUNK_SIZE = 10;
-    const SIZE = 40;
+    public const CHUNK_SIZE = 10;
+    public const SIZE = 40;
 
     /**
      * @var int
diff --git a/tests/Providers/PSR7ObjectProvider.php b/tests/Providers/PSR7ObjectProvider.php
index 7ac1bc294..3d0e73bf1 100644
--- a/tests/Providers/PSR7ObjectProvider.php
+++ b/tests/Providers/PSR7ObjectProvider.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -17,6 +18,10 @@
 use Psr\Http\Message\StreamFactoryInterface;
 use Psr\Http\Message\StreamInterface;
 
+use function array_merge;
+use function microtime;
+use function time;
+
 /**
  * Class PSR7ObjectProvider
  *
diff --git a/tests/Providers/PSR7ObjectProviderInterface.php b/tests/Providers/PSR7ObjectProviderInterface.php
index e2cfc1502..94d969a90 100644
--- a/tests/Providers/PSR7ObjectProviderInterface.php
+++ b/tests/Providers/PSR7ObjectProviderInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/ResponseEmitterTest.php b/tests/ResponseEmitterTest.php
index 447aaca0f..9f164c2f0 100644
--- a/tests/ResponseEmitterTest.php
+++ b/tests/ResponseEmitterTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -9,12 +10,31 @@
 
 namespace Slim\Tests;
 
+use ReflectionClass;
 use Slim\ResponseEmitter;
 use Slim\Tests\Assets\HeaderStack;
 use Slim\Tests\Mocks\MockStream;
 use Slim\Tests\Mocks\SlowPokeStream;
 use Slim\Tests\Mocks\SmallChunksStream;
 
+use function base64_decode;
+use function fopen;
+use function fwrite;
+use function in_array;
+use function popen;
+use function rewind;
+use function str_repeat;
+use function stream_filter_append;
+use function stream_filter_remove;
+use function stream_get_filters;
+use function strlen;
+use function trim;
+
+use const CONNECTION_ABORTED;
+use const CONNECTION_TIMEOUT;
+use const STREAM_FILTER_READ;
+use const STREAM_FILTER_WRITE;
+
 class ResponseEmitterTest extends TestCase
 {
     public function setUp(): void
@@ -294,7 +314,7 @@ public function testWillHandleInvalidConnectionStatusWithAnIndeterminateBody()
 
         $responseEmitter = new ResponseEmitter();
 
-        $mirror = new \ReflectionClass(ResponseEmitter::class);
+        $mirror = new ReflectionClass(ResponseEmitter::class);
         $emitBodyMethod = $mirror->getMethod('emitBody');
         $emitBodyMethod->setAccessible(true);
         $emitBodyMethod->invoke($responseEmitter, $response);
diff --git a/tests/Routing/DispatcherTest.php b/tests/Routing/DispatcherTest.php
index bade186fd..5ef716127 100644
--- a/tests/Routing/DispatcherTest.php
+++ b/tests/Routing/DispatcherTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -18,6 +19,11 @@
 use Slim\Routing\RoutingResults;
 use Slim\Tests\TestCase;
 
+use function dirname;
+use function microtime;
+use function uniqid;
+use function unlink;
+
 class DispatcherTest extends TestCase
 {
     public function testCreateDispatcher()
diff --git a/tests/Routing/FastRouteDispatcherTest.php b/tests/Routing/FastRouteDispatcherTest.php
index 5d1aaaea6..0f49c42d9 100644
--- a/tests/Routing/FastRouteDispatcherTest.php
+++ b/tests/Routing/FastRouteDispatcherTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -14,6 +15,7 @@
 use FastRoute\RouteCollector;
 use Slim\Routing\FastRouteDispatcher;
 use Slim\Tests\TestCase;
+
 use function FastRoute\simpleDispatcher;
 
 class FastRouteDispatcherTest extends TestCase
diff --git a/tests/Routing/RouteCollectorProxyTest.php b/tests/Routing/RouteCollectorProxyTest.php
index ed259fc52..4b10eb1c9 100644
--- a/tests/Routing/RouteCollectorProxyTest.php
+++ b/tests/Routing/RouteCollectorProxyTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Routing/RouteCollectorTest.php b/tests/Routing/RouteCollectorTest.php
index 1a2d88c3c..598c91fab 100644
--- a/tests/Routing/RouteCollectorTest.php
+++ b/tests/Routing/RouteCollectorTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -19,6 +20,12 @@
 use Slim\Routing\RouteCollectorProxy;
 use Slim\Tests\TestCase;
 
+use function dirname;
+use function file_exists;
+use function file_put_contents;
+use function sprintf;
+use function unlink;
+
 class RouteCollectorTest extends TestCase
 {
     /**
diff --git a/tests/Routing/RouteContextTest.php b/tests/Routing/RouteContextTest.php
index e8305268d..871843792 100644
--- a/tests/Routing/RouteContextTest.php
+++ b/tests/Routing/RouteContextTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Routing/RouteParserTest.php b/tests/Routing/RouteParserTest.php
index 4aed9bde4..7ba158db4 100644
--- a/tests/Routing/RouteParserTest.php
+++ b/tests/Routing/RouteParserTest.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Slim\Tests\Routing;
diff --git a/tests/Routing/RouteResolverTest.php b/tests/Routing/RouteResolverTest.php
index 47b4080e9..f2b7c5dd9 100644
--- a/tests/Routing/RouteResolverTest.php
+++ b/tests/Routing/RouteResolverTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -18,6 +19,8 @@
 use Slim\Routing\RoutingResults;
 use Slim\Tests\TestCase;
 
+use function sprintf;
+
 class RouteResolverTest extends TestCase
 {
     public function computeRoutingResultsDataProvider(): array
diff --git a/tests/Routing/RouteRunnerTest.php b/tests/Routing/RouteRunnerTest.php
index 709ea4f0c..b858108ea 100644
--- a/tests/Routing/RouteRunnerTest.php
+++ b/tests/Routing/RouteRunnerTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/Routing/RouteTest.php b/tests/Routing/RouteTest.php
index 0bd83e2e5..25491af03 100644
--- a/tests/Routing/RouteTest.php
+++ b/tests/Routing/RouteTest.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -34,6 +35,11 @@
 use Slim\Tests\Mocks\MockMiddlewareWithoutInterface;
 use Slim\Tests\Mocks\RequestHandlerTest;
 
+use function is_callable;
+use function is_string;
+use function ob_end_clean;
+use function ob_start;
+
 class RouteTest extends TestCase
 {
     /**
diff --git a/tests/TestCase.php b/tests/TestCase.php
index 3b4d64e9f..6b2ac3d57 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 4143a09ee..23184944d 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Slim Framework (https://slimframework.com)
  *
@@ -7,7 +8,50 @@
 
 declare(strict_types=1);
 
-require __DIR__ . '/../vendor/autoload.php';
+use AdrianSuter\Autoload\Override\Override;
+use Slim\ResponseEmitter;
+use Slim\Routing\RouteCollector;
+use Slim\Tests\Assets\HeaderStack;
+
+$classLoader = require __DIR__ . '/../vendor/autoload.php';
+
+//require __DIR__ . '/Assets/PhpFunctionOverrides.php';
+//require __DIR__ . '/Assets/PhpRoutingFunctionOverrides.php';
+
+Override::apply($classLoader, [
+    ResponseEmitter::class => [
+        'connection_status' => function (): int {
+            if (isset($GLOBALS['connection_status_return'])) {
+                return $GLOBALS['connection_status_return'];
+            }
 
-require __DIR__ . '/Assets/PhpFunctionOverrides.php';
-require __DIR__ . '/Assets/PhpRoutingFunctionOverrides.php';
+            return connection_status();
+        },
+        'header' => function (string $string, bool $replace = true, int $statusCode = null): void {
+            HeaderStack::push(
+                [
+                    'header' => $string,
+                    'replace' => $replace,
+                    'status_code' => $statusCode,
+                ]
+            );
+        },
+        'headers_sent' => function (): bool {
+            return false;
+        }
+    ],
+    RouteCollector::class => [
+        'is_readable' => function (string $file): bool {
+            if (stripos($file, 'non-readable.cache') !== false) {
+                return false;
+            }
+            return true;
+        },
+        'is_writable' => function (string $path): bool {
+            if (stripos($path, 'non-writable-directory') !== false) {
+                return false;
+            }
+            return true;
+        }
+    ]
+]);