[8.x] Fix json_last_error issue with setData (#42125)

* Fix json_last_error issue with setData

* Apply fixes from StyleCI

* Update JsonResponse.php

Co-authored-by: StyleCI Bot <[email protected]>
Co-authored-by: Taylor Otwell <[email protected]>

Author: 3 people

src/Illuminate/Http/JsonResponse.php

@@ -74,6 +74,9 @@ public function setData($data = [])
     {
         $this->original = $data;
 
+        // Ensure json_last_error() is cleared...
+        json_decode('[]');
+
         if ($data instanceof Jsonable) {
             $this->data = $data->toJson($this->encodingOptions);
         } elseif ($data instanceof JsonSerializable) {

tests/Integration/Http/JsonResponseTest.php

@@ -2,6 +2,7 @@
 
 namespace Illuminate\Tests\Integration\Http;
 
+use Illuminate\Contracts\Support\Jsonable;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Support\Facades\Route;
 use Orchestra\Testbench\TestCase;
@@ -27,4 +28,22 @@ public function jsonSerialize(): string
 
         $this->get('/response');
     }
+
+    public function testResponseSetDataPassesWithPriorJsonErrors()
+    {
+        $response = new JsonResponse();
+
+        // Trigger json_last_error() to have a non-zero value...
+        json_encode(['a' => acos(2)]);
+
+        $response->setData(new class implements Jsonable
+        {
+            public function toJson($options = 0): string
+            {
+                return '{}';
+            }
+        });
+
+        $this->assertJson($response->getContent());
+    }
 }