[Agent][Platform][OpenAI] Add stream usage support

src/agent/src/Toolbox/StreamResult.php

@@ -33,7 +33,13 @@ public function getContent(): \Generator
             if ($value instanceof ToolCallResult) {
                 yield from ($this->handleToolCallsCallback)($value, Message::ofAssistant($streamedResult))->getContent();
 
-                break;
+                continue;
+            }
+
+            if (!\is_string($value)) {
+                yield $value;
+
+                continue;
             }
 
             $streamedResult .= $value;

src/agent/tests/Toolbox/StreamResultTest.php

@@ -0,0 +1,132 @@
+<?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\Agent\Tests\Toolbox;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\AI\Agent\Toolbox\StreamResult as ToolboxStreamResult;
+use Symfony\AI\Platform\Message\AssistantMessage;
+use Symfony\AI\Platform\Metadata\TokenUsage;
+use Symfony\AI\Platform\Result\BaseResult;
+use Symfony\AI\Platform\Result\ToolCall;
+use Symfony\AI\Platform\Result\ToolCallResult;
+
+final class StreamResultTest extends TestCase
+{
+    public function testStreamsPlainChunksWithoutToolCall()
+    {
+        $chunks = ['He', 'llo'];
+        $generator = (function () use ($chunks) {
+            foreach ($chunks as $c) {
+                yield $c;
+            }
+        })();
+
+        $callbackCalled = false;
+        $callback = function () use (&$callbackCalled) {
+            $callbackCalled = true;
+
+            // Return any result, won't be used in this test
+            return new class extends BaseResult {
+                public function getContent(): iterable
+                {
+                    yield 'ignored';
+                }
+            };
+        };
+
+        $stream = new ToolboxStreamResult($generator, $callback);
+        $received = [];
+        foreach ($stream->getContent() as $value) {
+            $received[] = $value;
+        }
+
+        $this->assertSame($chunks, $received);
+        $this->assertFalse($callbackCalled, 'Callback should not be called when no ToolCallResult appears.');
+    }
+
+    public function testInvokesCallbackOnToolCallAndYieldsItsContent()
+    {
+        $toolCallResult = new ToolCallResult(new ToolCall('id1', 'tool1', ['arg' => 'value']));
+
+        $generator = (function () use ($toolCallResult) {
+            yield 'He';
+            yield 'llo';
+            yield $toolCallResult;
+            yield 'AFTER';
+        })();
+
+        $receivedAssistantMessage = null;
+        $receivedToolCallResult = null;
+
+        $callback = function (ToolCallResult $result, AssistantMessage $assistantMessage) use (&$receivedAssistantMessage, &$receivedToolCallResult) {
+            $receivedToolCallResult = $result;
+            $receivedAssistantMessage = $assistantMessage;
+
+            // Return a result that itself yields more chunks
+            return new class extends BaseResult {
+                public function getContent(): iterable
+                {
+                    yield ' world';
+                    yield '!';
+                }
+            };
+        };
+
+        $stream = new ToolboxStreamResult($generator, $callback);
+
+        $received = [];
+        foreach ($stream->getContent() as $value) {
+            $received[] = $value;
+        }
+
+        $this->assertSame(['He', 'llo', ' world', '!', 'AFTER'], $received);
+        $this->assertInstanceOf(ToolCallResult::class, $receivedToolCallResult);
+        $this->assertInstanceOf(AssistantMessage::class, $receivedAssistantMessage);
+        $this->assertSame('Hello', $receivedAssistantMessage->content);
+    }
+
+    public function testStreamsPlainChunksWithTokenUsage()
+    {
+        $chunks = [
+            'He',
+            'llo',
+            new TokenUsage(),
+        ];
+        $generator = (function () use ($chunks) {
+            foreach ($chunks as $c) {
+                yield $c;
+            }
+        })();
+
+        $callbackCalled = false;
+        $callback = function () use (&$callbackCalled) {
+            $callbackCalled = true;
+
+            // Return any result, won't be used in this test
+            return new class extends BaseResult {
+                public function getContent(): iterable
+                {
+                    yield 'ignored';
+                }
+            };
+        };
+
+        $stream = new ToolboxStreamResult($generator, $callback);
+        $received = [];
+        foreach ($stream->getContent() as $value) {
+            $received[] = $value;
+        }
+
+        $this->assertSame($chunks, $received);
+        $this->assertFalse($callbackCalled, 'Callback should not be called when no ToolCallResult appears.');
+    }
+}

src/platform/src/Bridge/OpenAi/Gpt/ResultConverter.php

@@ -17,6 +17,7 @@
 use Symfony\AI\Platform\Exception\ContentFilterException;
 use Symfony\AI\Platform\Exception\RateLimitExceededException;
 use Symfony\AI\Platform\Exception\RuntimeException;
+use Symfony\AI\Platform\Metadata\TokenUsage;
 use Symfony\AI\Platform\Model;
 use Symfony\AI\Platform\Result\ChoiceResult;
 use Symfony\AI\Platform\Result\RawHttpResult;
@@ -106,6 +107,16 @@ private function convertStream(HttpResponse $result): \Generator
                 yield new ToolCallResult(...array_map($this->convertToolCall(...), $toolCalls));
             }
 
+            if ($usage = $data['usage'] ?? null) {
+                yield new TokenUsage(
+                    promptTokens: $usage['prompt_tokens'] ?? null,
+                    completionTokens: $usage['completion_tokens'] ?? null,
+                    thinkingTokens: $usage['completion_tokens_details']['reasoning_tokens'] ?? null,
+                    cachedTokens: $usage['prompt_tokens_details']['cached_tokens'] ?? null,
+                    totalTokens: $usage['total_tokens'] ?? null,
+                );
+            }
+
             if (!isset($data['choices'][0]['delta']['content'])) {
                 continue;
             }

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

@@ -0,0 +1,139 @@
+<?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\OpenAi\Gpt;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\AI\Platform\Bridge\OpenAi\Gpt\ResultConverter;
+use Symfony\AI\Platform\Metadata\TokenUsage;
+use Symfony\AI\Platform\Result\RawHttpResult;
+use Symfony\AI\Platform\Result\StreamResult;
+use Symfony\AI\Platform\Result\ToolCallResult;
+use Symfony\Component\HttpClient\EventSourceHttpClient;
+use Symfony\Component\HttpClient\MockHttpClient;
+use Symfony\Component\HttpClient\Response\MockResponse;
+
+final class ResultConverterStreamTest extends TestCase
+{
+    public function testStreamTextDeltas()
+    {
+        $sseBody = ''
+            ."data: {\"choices\":[{\"delta\":{\"role\":\"assistant\"},\"index\":0}]}\n\n"
+            ."data: {\"choices\":[{\"delta\":{\"content\":\"Hello \"},\"index\":0}]}\n\n"
+            ."data: {\"choices\":[{\"delta\":{\"content\":\"world\"},\"index\":0}]}\n\n"
+            ."data: {\"choices\":[{\"delta\":{},\"index\":0,\"finish_reason\":\"stop\"}]}\n\n"
+            ."data: [DONE]\n\n";
+
+        $mockClient = new MockHttpClient([
+            new MockResponse($sseBody, [
+                'http_code' => 200,
+                'response_headers' => [
+                    'content-type' => 'text/event-stream',
+                ],
+            ]),
+        ]);
+        $esClient = new EventSourceHttpClient($mockClient);
+        $asyncResponse = $esClient->request('GET', 'http://localhost/stream');
+
+        $converter = new ResultConverter();
+        $result = $converter->convert(new RawHttpResult($asyncResponse), ['stream' => true]);
+
+        $this->assertInstanceOf(StreamResult::class, $result);
+        $chunks = [];
+        foreach ($result->getContent() as $delta) {
+            $chunks[] = $delta;
+        }
+
+        // Only text deltas are yielded; role and finish chunks are ignored
+        $this->assertSame(['Hello ', 'world'], $chunks);
+    }
+
+    public function testStreamToolCallsAreAssembledAndYielded()
+    {
+        // Simulate a tool call that is streamed in multiple argument parts
+        $sseBody = ''
+            ."data: {\"choices\":[{\"delta\":{\"role\":\"assistant\"},\"index\":0}]}\n\n"
+            ."data: {\"choices\":[{\"delta\":{\"tool_calls\":[{\"id\":\"call_123\",\"type\":\"function\",\"function\":{\"name\":\"test_function\",\"arguments\":\"{\\\"arg1\\\": \\\"value1\\\"}\"}}]},\"index\":0}]}\n\n"
+            ."data: {\"choices\":[{\"delta\":{},\"index\":0,\"finish_reason\":\"tool_calls\"}]}\n\n"
+            ."data: [DONE]\n\n";
+
+        $mockClient = new MockHttpClient([
+            new MockResponse($sseBody, [
+                'http_code' => 200,
+                'response_headers' => [
+                    'content-type' => 'text/event-stream',
+                ],
+            ]),
+        ]);
+        $esClient = new EventSourceHttpClient($mockClient);
+        $asyncResponse = $esClient->request('GET', 'http://localhost/stream');
+
+        $converter = new ResultConverter();
+        $result = $converter->convert(new RawHttpResult($asyncResponse), ['stream' => true]);
+
+        $this->assertInstanceOf(StreamResult::class, $result);
+
+        $yielded = [];
+        foreach ($result->getContent() as $delta) {
+            $yielded[] = $delta;
+        }
+
+        // Expect only one yielded item and it should be a ToolCallResult
+        $this->assertCount(1, $yielded);
+        $this->assertInstanceOf(ToolCallResult::class, $yielded[0]);
+        /** @var ToolCallResult $toolCallResult */
+        $toolCallResult = $yielded[0];
+        $toolCalls = $toolCallResult->getContent();
+
+        $this->assertCount(1, $toolCalls);
+        $this->assertSame('call_123', $toolCalls[0]->getId());
+        $this->assertSame('test_function', $toolCalls[0]->getName());
+        $this->assertSame(['arg1' => 'value1'], $toolCalls[0]->getArguments());
+    }
+
+    public function testStreamTokenUsage()
+    {
+        $sseBody = ''
+            ."data: {\"choices\":[{\"delta\":{\"role\":\"assistant\"},\"index\":0}]}\n\n"
+            ."data: {\"choices\":[{\"delta\":{\"content\":\"Hello \"},\"index\":0}]}\n\n"
+            ."data: {\"choices\":[{\"delta\":{\"content\":\"world\"},\"index\":0}]}\n\n"
+            ."data: {\"choices\":[{\"delta\":{},\"index\":0,\"finish_reason\":\"stop\"}]}\n\n"
+            ."data: {\"usage\":{\"prompt_tokens\":1039,\"completion_tokens\":10,\"total_tokens\":1049,\"prompt_tokens_details\":{\"cached_tokens\":0,\"audio_tokens\":0},\"completion_tokens_details\":{\"reasoning_tokens\":0,\"audio_tokens\":0,\"accepted_prediction_tokens\":0,\"rejected_prediction_tokens\":0}}}\n\n"
+            ."data: [DONE]\n\n";
+
+        $mockClient = new MockHttpClient([
+            new MockResponse($sseBody, [
+                'http_code' => 200,
+                'response_headers' => [
+                    'content-type' => 'text/event-stream',
+                ],
+            ]),
+        ]);
+        $esClient = new EventSourceHttpClient($mockClient);
+        $asyncResponse = $esClient->request('GET', 'http://localhost/stream');
+
+        $converter = new ResultConverter();
+        $result = $converter->convert(new RawHttpResult($asyncResponse), ['stream' => true]);
+
+        $this->assertInstanceOf(StreamResult::class, $result);
+
+        $yielded = [];
+        foreach ($result->getContent() as $delta) {
+            $yielded[] = $delta;
+        }
+        $this->assertCount(3, $yielded);
+        $this->assertInstanceOf(TokenUsage::class, $yielded[2]);
+        $this->assertSame(1039, $yielded[2]->promptTokens);
+        $this->assertSame(10, $yielded[2]->completionTokens);
+        $this->assertSame(1049, $yielded[2]->totalTokens);
+        $this->assertSame(0, $yielded[2]->cachedTokens);
+    }
+}