add assertHasJsonValidationError assertion

Signed-off-by: Tonko Mulder <[email protected]>

Author: Treggats

src/Tempest/Framework/Testing/Http/TestResponseHelper.php

@@ -6,6 +6,7 @@
 
 use Closure;
 use Generator;
+use JsonException;
 use PHPUnit\Framework\Assert;
 use Tempest\Http\Cookie\CookieManager;
 use Tempest\Http\Response;
@@ -255,6 +256,29 @@ function ($carry) use ($keys) {
         return $this;
     }
 
+    public function assertHasJsonValidationError(string $key, ?Closure $test = null): self
+    {
+        Assert::assertInstanceOf(Invalid::class, $this->response);
+
+        $validationErrors = array_map(function ($failingRules) use ($key) {
+            try {
+                $errors = json_decode($failingRules, true, 512, JSON_THROW_ON_ERROR);
+            } catch (JsonException) {
+                $errors = [];
+            }
+
+            return arr($errors)->filter(fn (array $_error, $errorKey) => $errorKey === $key)->flatten()->first();
+        }, $this->response->getHeader('x-validation')->values);
+
+        Assert::assertNotEmpty($validationErrors, message: 'no validation errors found');
+
+        if ($test !== null) {
+            $test($validationErrors);
+        }
+
+        return $this;
+    }
+
     public function assertHasNoJsonValidationErrors(): self
     {
         Assert::assertNotInstanceOf(Invalid::class, $this->response);