diff --git a/.github/workflows/be_base.yml b/.github/workflows/be_base.yml
index a27d4ea0..1320c0cf 100644
--- a/.github/workflows/be_base.yml
+++ b/.github/workflows/be_base.yml
@@ -28,7 +28,8 @@ jobs:
           --coverage-xml=coverage/coverage-xml
           --log-junit=coverage/junit.xml
         # https://infection.github.io/guide/command-line-options.html#coverage
-      - uses: actions/upload-artifact@v4
+      - if: always()
+        uses: actions/upload-artifact@v4
         with:
           name: coverage-${{ inputs.runs-on }}
           path: be/coverage/clover.xml
diff --git a/be/app/Http/Middleware/DumpJsonResponse.php b/be/app/Http/Middleware/DumpJsonResponse.php
index e190a45e..8880820c 100644
--- a/be/app/Http/Middleware/DumpJsonResponse.php
+++ b/be/app/Http/Middleware/DumpJsonResponse.php
@@ -4,11 +4,12 @@
 
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\Request;
+use Symfony\Component\HttpFoundation\Response;
 
 class DumpJsonResponse
 {
-    /** @param \Closure(Request): (\Symfony\Component\HttpFoundation\Response) $next */
-    public function handle(Request $request, \Closure $next): mixed
+    /** @param \Closure(Request): (Response) $next */
+    public function handle(Request $request, \Closure $next): Response
     {
         $response = $next($request);
         if ($response instanceof JsonResponse) {
diff --git a/be/tests/Feature/App/Exceptions/HandlerTest.php b/be/tests/Feature/App/Exceptions/HandlerTest.php
new file mode 100644
index 00000000..f05f71ec
--- /dev/null
+++ b/be/tests/Feature/App/Exceptions/HandlerTest.php
@@ -0,0 +1,51 @@
+<?php
+
+namespace Tests\Feature\App\Exceptions;
+
+use App\Exceptions\Handler;
+use Illuminate\Container\Container;
+use Illuminate\Support\Facades\App;
+use Illuminate\Validation\ValidationException;
+use Illuminate\Validation\Factory;
+use ReflectionMethod;
+use Symfony\Component\HttpFoundation\Response;
+use Tests\TestCase;
+
+class HandlerTest extends TestCase
+{
+    private Handler $sut;
+    private Factory $validatorFactory;
+    private ReflectionMethod $convertValidationExceptionToResponse;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->sut = new Handler(Container::getInstance());
+        $this->validatorFactory = App::make(Factory::class);
+        $this->convertValidationExceptionToResponse = new ReflectionMethod(
+            Handler::class,
+            'convertValidationExceptionToResponse',
+        );
+    }
+
+    private function invokeConvertValidationExceptionToResponse(ValidationException $exception): Response
+    {
+        return $this->convertValidationExceptionToResponse->invoke($this->sut, $exception, null);
+    }
+
+    public function testNotConvertValidationExceptionToResponse(): void
+    {
+        $exception = new ValidationException($this->validatorFactory->make([], []), new Response('test'));
+        $response = $this->invokeConvertValidationExceptionToResponse($exception);
+        self::assertEquals('test', $response->getContent());
+    }
+
+    public function testConvertValidationExceptionToResponse(): void
+    {
+        $exception = new ValidationException($this->validatorFactory->make(['test' => 'int'], ['test' => 'int']));
+        $response = $this->invokeConvertValidationExceptionToResponse($exception);
+        $responseJSON = \Safe\json_decode($response->getContent());
+        self::assertEquals(40000, $responseJSON->errorCode);
+        self::assertEquals('The test field must be an integer.', $responseJSON->errorInfo->test[0]);
+    }
+}
diff --git a/be/tests/Feature/App/Http/Middleware/DumpJsonResponseTest.php b/be/tests/Feature/App/Http/Middleware/DumpJsonResponseTest.php
new file mode 100644
index 00000000..3bbecce4
--- /dev/null
+++ b/be/tests/Feature/App/Http/Middleware/DumpJsonResponseTest.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace Tests\Feature\App\Http\Middleware;
+
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\Request;
+use PHPUnit\Framework\TestCase;
+
+class DumpJsonResponseTest extends TestCase
+{
+    public function testHandle(): void
+    {
+        $next = static fn() => JsonResponse::fromJsonString(\Safe\json_encode(['test' => 'test']));
+        $sut = new DumpJsonResponse();
+        self::assertEquals(<<<JSON
+        {
+            "test": "test"
+        }
+        JSON, $sut->handle(Request::create('', server: ['HTTP_ACCEPT' => 'application/json']), $next)->getContent());
+
+        self::assertEquals(<<<HTML
+        <h4>a15 bytes</h4>
+        <div id="root"></div>
+        <script type="module">
+            import ReactJsonView from 'http://localhost/be/assets/react-json-view.js';
+            import { createElement } from 'http://localhost/be/assets/react.js';
+            import { createRoot } from 'http://localhost/be/assets/react-dom.js';
+
+            const root = createRoot(document.getElementById('root'));
+            root.render(createElement(ReactJsonView.default, { src: {"test":"test"}, quotesOnKeys: false }));
+        </script>
+        <style>
+            .object-content {
+                content-visibility: auto;
+            }
+        </style>
+        HTML, ($sut)->handle(Request::create(''), $next)->getContent());
+    }
+}