Added validation exception middleware and validation test [SLE-197]

config/middleware.php

@@ -13,6 +13,9 @@
     // Has to be after Routing
     $app->add(Selective\BasePath\BasePathMiddleware::class);
 
+    // Returns a response with validation errors
+    $app->add(\App\Application\Middleware\ValidationExceptionMiddleware::class);
+
     // Handle and log notices and warnings (throws ErrorException if displayErrorDetails is true)
     $app->add(\App\Application\Middleware\NonFatalErrorHandlerMiddleware::class);
     // Set error handler to custom DefaultErrorHandler (defined in container.php)

src/Application/Middleware/ValidationExceptionMiddleware.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace App\Application\Middleware;
+
+use App\Application\Responder\JsonEncoder;
+use App\Domain\Exception\ValidationException;
+use Psr\Http\Message\ResponseFactoryInterface;
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use Psr\Http\Server\MiddlewareInterface;
+use Psr\Http\Server\RequestHandlerInterface;
+
+final readonly class ValidationExceptionMiddleware implements MiddlewareInterface
+{
+    public function __construct(
+        private ResponseFactoryInterface $responseFactory,
+        private JsonEncoder $jsonEncoder,
+    ) {
+    }
+
+    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
+    {
+        try {
+            return $handler->handle($request);
+        } catch (ValidationException $validationException) {
+            // Create response (status code and header are added later)
+            $response = $this->responseFactory->createResponse();
+
+            $responseData = [
+                'status' => 'error',
+                'message' => $validationException->getMessage(),
+                // The error format is already transformed to the format that the frontend expects in the exception.
+                'data' => ['errors' => $validationException->validationErrors],
+            ];
+
+            return $this->jsonEncoder->encodeAndAddToResponse($response, $responseData, 422);
+        }
+    }
+}

tests/Integration/User/UserCreateActionTest.php

@@ -36,4 +36,42 @@ public function testUserCreateAction(): void
         // Assert that the user was created in the database
         $this->assertTableRow($testUserData, 'user', $testUserData['id']);
     }
+
+    public function testUserCreateActionInvalid(): void
+    {
+        // Set invalid data
+        $invalidUserData = [
+            'first_name' => 'J', // min length is 2
+            'last_name' => 'D', // min length is 2
+            'email' => 'invalid-email',
+        ];
+        // Make request
+        $request = $this->createJsonRequest('POST', $this->urlFor('user-create'), $invalidUserData);
+        $response = $this->app->handle($request);
+
+        // Assert status code
+        self::assertSame(StatusCodeInterface::STATUS_UNPROCESSABLE_ENTITY, $response->getStatusCode());
+
+        // Assert that no database record was created
+        $this->assertTableRowCount(0, 'user');
+
+        // Assert that the response contains the validation error messages
+        $this->assertJsonData([
+            'status' => 'error',
+            'message' => 'Validation error',
+            'data' => [
+                'errors' => [
+                    'first_name' => [
+                        0 => 'Minimum length is 2',
+                    ],
+                    'last_name' => [
+                        0 => 'Minimum length is 2',
+                    ],
+                    'email' => [
+                        0 => 'Invalid email',
+                    ],
+                ],
+            ],
+        ], $response);
+    }
 }