minor #702 [Platform] Add error handling tests (OskarStark)

This PR was squashed before being merged into the main branch.

Discussion
----------

[Platform] Add error handling tests

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| Docs?         | no
| Issues        | Follows #608
| License       | MIT

Commits
-------

cac9a7e [Platform] Add error handling tests

Author: OskarStark

src/platform/tests/Bridge/Gemini/Gemini/ResultConverterTest.php

@@ -0,0 +1,43 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\AI\Platform\Tests\Bridge\Gemini\Gemini;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\AI\Platform\Bridge\Gemini\Gemini\ResultConverter;
+use Symfony\AI\Platform\Exception\RuntimeException;
+use Symfony\AI\Platform\Result\RawHttpResult;
+use Symfony\Contracts\HttpClient\ResponseInterface;
+
+/**
+ * @author Oskar Stark <[email protected]>
+ */
+final class ResultConverterTest extends TestCase
+{
+    public function testConvertThrowsExceptionWithDetailedErrorInformation()
+    {
+        $converter = new ResultConverter();
+        $httpResponse = self::createMock(ResponseInterface::class);
+        $httpResponse->method('getStatusCode')->willReturn(400);
+        $httpResponse->method('toArray')->willReturn([
+            'error' => [
+                'code' => 400,
+                'status' => 'INVALID_ARGUMENT',
+                'message' => 'Invalid request: The model does not support this feature.',
+            ],
+        ]);
+
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('Error "400" - "INVALID_ARGUMENT": "Invalid request: The model does not support this feature.".');
+
+        $converter->convert(new RawHttpResult($httpResponse));
+    }
+}

src/platform/tests/Bridge/OpenAi/Gpt/ResultConverterTest.php

@@ -226,4 +226,23 @@ public function testThrowsBadRequestExceptionOnBadRequestResponseWithNoResponseB
 
         $converter->convert(new RawHttpResult($httpResponse));
     }
+
+    public function testThrowsDetailedErrorException()
+    {
+        $converter = new ResultConverter();
+        $httpResponse = self::createMock(ResponseInterface::class);
+        $httpResponse->method('toArray')->willReturn([
+            'error' => [
+                'code' => 'invalid_request_error',
+                'type' => 'invalid_request',
+                'param' => 'model',
+                'message' => 'The model `gpt-5` does not exist',
+            ],
+        ]);
+
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('Error "invalid_request_error"-invalid_request (model): "The model `gpt-5` does not exist".');
+
+        $converter->convert(new RawHttpResult($httpResponse));
+    }
 }