[Demo] Add stream example command

demo/src/Blog/Command/StreamCommand.php

@@ -0,0 +1,54 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App\Blog\Command;
+
+use Symfony\AI\Agent\AgentInterface;
+use Symfony\AI\Platform\Message\Message;
+use Symfony\AI\Platform\Message\MessageBag;
+use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Style\SymfonyStyle;
+
+#[AsCommand('app:blog:stream', 'An example command to demonstrate streaming output.')]
+final readonly class StreamCommand
+{
+    public function __construct(
+        private AgentInterface $blogAgent,
+    ) {
+    }
+
+    public function __invoke(SymfonyStyle $io): int
+    {
+        $io->title('Stream Example Command');
+        $io->text('This command demonstrates streaming output in the console.');
+
+        $io->comment('Make sure to have ChromaDB running and the blog indexed, see README.');
+        $io->comment('You can use -vvv or --profile to get more insights into the execution.');
+
+        $question = $io->ask(
+            'Ask a question about the content of the Symfony blog',
+            'Tell me about the latest Symfony features.',
+        );
+        $messages = new MessageBag(Message::ofUser($question));
+
+        $io->section('Agent Response:');
+        $result = $this->blogAgent->call($messages, ['stream' => true]);
+
+        foreach ($result->getContent() as $word) {
+            $io->write($word);
+        }
+
+        $io->newLine(2);
+        $io->success('The command has completed successfully.');
+
+        return 0;
+    }
+}

demo/tests/Blog/Command/StreamCommandTest.php

@@ -0,0 +1,69 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App\Tests\Blog\Command;
+
+use App\Blog\Command\StreamCommand;
+use PHPUnit\Framework\TestCase;
+use Symfony\AI\Agent\AgentInterface;
+use Symfony\AI\Platform\Message\MessageBag;
+use Symfony\AI\Platform\Metadata\Metadata;
+use Symfony\AI\Platform\Result\RawResultInterface;
+use Symfony\AI\Platform\Result\ResultInterface;
+use Symfony\Component\Console\Input\ArrayInput;
+use Symfony\Component\Console\Output\BufferedOutput;
+use Symfony\Component\Console\Style\SymfonyStyle;
+
+class StreamCommandTest extends TestCase
+{
+    public function testStreamCommandOutputsStreamedContentAndSuccess()
+    {
+        $mockAgent = $this->createMock(AgentInterface::class);
+        $mockAgent
+            ->method('call')
+            ->with($this->isInstanceOf(MessageBag::class), ['stream' => true])
+            ->willReturn(new class implements ResultInterface {
+                public function getContent(): iterable
+                {
+                    yield 'Hello';
+                    yield ' ';
+                    yield 'world';
+                    yield '!';
+                }
+
+                public function getMetadata(): Metadata
+                {
+                }
+
+                public function getRawResult(): ?RawResultInterface
+                {
+                }
+
+                public function setRawResult(RawResultInterface $rawResult): void
+                {
+                }
+            });
+
+        $input = new ArrayInput([]);
+        $input->setInteractive(false);
+        $io = new SymfonyStyle($input, $buffer = new BufferedOutput());
+        $command = new StreamCommand($mockAgent);
+        $command->__invoke($io);
+
+        $output = $buffer->fetch();
+
+        $this->assertStringContainsString('Stream Example Command', $output);
+        $this->assertStringContainsString('This command demonstrates streaming output', $output);
+        $this->assertStringContainsString('Agent Response:', $output);
+        $this->assertStringContainsString('Hello world!', $output);
+        $this->assertStringContainsString('The command has completed successfully.', $output);
+    }
+}