Add updated chat unit test

Author: charvimehradu

Tests/OpenAIProvider/ChatTest.php

@@ -0,0 +1,59 @@
+<?php
+
+use Joomla\Http\Http;
+use Joomla\Http\HttpFactory;
+use Joomla\Http\Response as HttpResponse;
+use Joomla\AI\Provider\OpenAIProvider;
+use PHPUnit\Framework\TestCase;
+
+class ChatTest extends TestCase
+{
+    public function testSimpleChatCompletion()
+    {
+        echo "Test 1: Test chat method with a simple prompt\n";
+
+        $fakeChatResponseBody = json_encode([
+            'id'      => 'chatcmpl-test',
+            'object'  => 'chat.completion',
+            'created' => time(),
+            'model'   => 'gpt-4o-mini',
+            'usage'   => ['prompt_tokens' => 5, 'completion_tokens' => 7, 'total_tokens' => 12],
+            'choices' => [
+                [
+                    'index'         => 0,
+                    'message'       => ['role' => 'assistant', 'content' => 'All good here!'],
+                    'finish_reason' => 'stop',
+                ],
+            ],
+        ]);
+
+        $httpFactoryMock  = $this->createMock(HttpFactory::class);
+        $httpClientMock   = $this->createMock(Http::class);
+
+        $httpFactoryMock->method('getHttp')->willReturn($httpClientMock);
+
+        $response = new HttpResponse('php://memory', 200, ['Content-Type' => 'application/json']);
+        $stream   = $response->getBody();
+        $stream->write($fakeChatResponseBody);
+
+        $httpClientMock->method('post')->willReturn($response);
+
+        $provider = new OpenAIProviderNoModeration(['api_key' => 'test-api-key'], $httpFactoryMock);
+
+        $response = $provider->chat('Hello! How are you?', ['model' => 'gpt-4o-mini']);
+
+        $this->assertEquals(200, $response->getStatusCode());
+        $this->assertSame('All good here!', $response->getContent());
+        $metadata = $response->getMetadata();
+        $this->assertArrayHasKey('model', $metadata);
+        $this->assertArrayHasKey('usage', $metadata);
+    }
+}
+
+class OpenAIProviderNoModeration extends OpenAIProvider
+{
+    protected function moderateInput($input, array $options = []): bool
+    {
+        return false;
+    }
+}