bug #1436 [Platform][Perplexity] Fix Metadata handling on Perplexity streams (chr-hertel)

This PR was merged into the main branch.

Discussion
----------

[Platform][Perplexity] Fix Metadata handling on Perplexity streams

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| Docs?         | no
| Issues        |
| License       | MIT

A bit weird tho with the metadata handling on the result instance in the example - `DeferredResult` is not working correct

Commits
-------

9072e72c Fix Metadata handling on Perplexity streams

examples/perplexity/academic-search.php

@@ -27,5 +27,5 @@ $result = $platform->invoke('sonar', $messages, [
 echo $result->asText().\PHP_EOL;
 echo \PHP_EOL;
 
-print_search_results($result->getMetadata());
-print_citations($result->getMetadata());
+print_search_results($result->getMetadata()->get('search_results'));
+print_citations($result->getMetadata()->get('citations'));

examples/perplexity/bootstrap.php

@@ -9,18 +9,13 @@
  * file that was distributed with this source code.
  */
 
-use Symfony\AI\Platform\Metadata\Metadata;
-
 require_once dirname(__DIR__).'/bootstrap.php';
 
-function print_search_results(Metadata $metadata): void
+/**
+ * @param array<int, array<string, string>> $searchResults
+ */
+function print_search_results(array $searchResults): void
 {
-    $searchResults = $metadata->get('search_results');
-
-    if (null === $searchResults) {
-        return;
-    }
-
     echo 'Search results:'.\PHP_EOL;
 
     if (0 === count($searchResults)) {
@@ -40,14 +35,11 @@ function print_search_results(Metadata $metadata): void
     }
 }
 
-function print_citations(Metadata $metadata): void
+/**
+ * @param array<int, string> $citations
+ */
+function print_citations(array $citations): void
 {
-    $citations = $metadata->get('citations');
-
-    if (null === $citations) {
-        return;
-    }
-
     echo 'Citations:'.\PHP_EOL;
 
     if (0 === count($citations)) {

examples/perplexity/image-input-url.php

@@ -29,5 +29,5 @@ $result = $platform->invoke('sonar', $messages);
 
 echo $result->asText().\PHP_EOL;
 
-print_search_results($result->getMetadata());
-print_citations($result->getMetadata());
+print_search_results($result->getMetadata()->get('search_results'));
+print_citations($result->getMetadata()->get('citations'));

examples/perplexity/pdf-input-url.php

@@ -28,5 +28,5 @@ $result = $platform->invoke('sonar', $messages);
 
 echo $result->asText().\PHP_EOL;
 
-print_search_results($result->getMetadata());
-print_citations($result->getMetadata());
+print_search_results($result->getMetadata()->get('search_results'));
+print_citations($result->getMetadata()->get('citations'));

examples/perplexity/stream.php

@@ -30,5 +30,5 @@ foreach ($result->asStream() as $word) {
 }
 echo \PHP_EOL;
 
-print_search_results($result->getMetadata());
-print_citations($result->getMetadata());
+print_search_results($result->getResult()->getMetadata()->get('search_results'));
+print_citations($result->getResult()->getMetadata()->get('citations'));

examples/perplexity/web-search.php

@@ -30,5 +30,5 @@ $result = $platform->invoke('sonar', $messages, [
 echo $result->asText().\PHP_EOL;
 echo \PHP_EOL;
 
-print_search_results($result->getMetadata());
-print_citations($result->getMetadata());
+print_search_results($result->getMetadata()->get('search_results'));
+print_citations($result->getMetadata()->get('citations'));

src/platform/src/Bridge/Perplexity/ResultConverter.php

@@ -12,7 +12,6 @@
 namespace Symfony\AI\Platform\Bridge\Perplexity;
 
 use Symfony\AI\Platform\Exception\RuntimeException;
-use Symfony\AI\Platform\Metadata\Metadata;
 use Symfony\AI\Platform\Model;
 use Symfony\AI\Platform\Result\ChoiceResult;
 use Symfony\AI\Platform\Result\RawResultInterface;
@@ -34,7 +33,7 @@ final class ResultConverter implements ResultConverterInterface
     public function convert(RawResultInterface $result, array $options = []): ResultInterface
     {
         if ($options['stream'] ?? false) {
-            return new StreamResult($this->convertStream($result));
+            return new StreamResult($this->convertStream($result), [new StreamListener()]);
         }
 
         $data = $result->getData();
@@ -67,26 +66,19 @@ final class ResultConverter implements ResultConverterInterface
 
     private function convertStream(RawResultInterface $result): \Generator
     {
-        $searchResults = $citations = [];
-        /** @var Metadata $metadata */
-        $metadata = yield;
-
         foreach ($result->getDataStream() as $data) {
             if (isset($data['choices'][0]['delta']['content'])) {
                 yield $data['choices'][0]['delta']['content'];
             }
-
-            if (isset($data['search_results'])) {
-                $searchResults = $data['search_results'];
-            }
-
-            if (isset($data['citations'])) {
-                $citations = $data['citations'];
-            }
         }
 
-        $metadata->add('search_results', $searchResults);
-        $metadata->add('citations', $citations);
+        if (isset($data['search_results'])) {
+            yield ['search_results' => $data['search_results']];
+        }
+
+        if (isset($data['citations'])) {
+            yield ['citations' => $data['citations']];
+        }
     }
 
     /**

src/platform/src/Bridge/Perplexity/StreamListener.php

@@ -0,0 +1,40 @@
+<?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 Symfony\AI\Platform\Bridge\Perplexity;
+
+use Symfony\AI\Platform\Result\Stream\AbstractStreamListener;
+use Symfony\AI\Platform\Result\Stream\ChunkEvent;
+
+/**
+ * @author Christopher Hertel <mail@christopher-hertel.de>
+ */
+final class StreamListener extends AbstractStreamListener
+{
+    public function onChunk(ChunkEvent $event): void
+    {
+        $chunk = $event->getChunk();
+
+        if (!\is_array($chunk)) {
+            return;
+        }
+
+        if (isset($chunk['search_results'])) {
+            $event->getMetadata()->add('search_results', $chunk['search_results']);
+            $event->skipChunk();
+        }
+
+        if (isset($chunk['citations'])) {
+            $event->getMetadata()->add('citations', $chunk['citations']);
+            $event->skipChunk();
+        }
+    }
+}

src/platform/src/Bridge/Perplexity/Tests/StreamListenerTest.php

@@ -0,0 +1,88 @@
+<?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 Symfony\AI\Platform\Bridge\Perplexity\Tests;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\AI\Platform\Bridge\Perplexity\StreamListener;
+use Symfony\AI\Platform\Result\StreamResult;
+
+final class StreamListenerTest extends TestCase
+{
+    public function testSearchResultsAreAddedToMetadataAndChunkIsSkipped()
+    {
+        $searchResults = [['url' => 'https://example.com', 'title' => 'Example']];
+        $streamResult = new StreamResult((static function () use ($searchResults): \Generator {
+            yield ['search_results' => $searchResults];
+            yield 'Hello World';
+        })());
+
+        $streamResult->addListener(new StreamListener());
+
+        $chunks = iterator_to_array($streamResult->getContent());
+
+        $this->assertSame(['Hello World'], $chunks);
+        $this->assertTrue($streamResult->getMetadata()->has('search_results'));
+        $this->assertSame($searchResults, $streamResult->getMetadata()->get('search_results'));
+    }
+
+    public function testCitationsAreAddedToMetadataAndChunkIsSkipped()
+    {
+        $citations = ['https://example.com/1', 'https://example.com/2'];
+        $streamResult = new StreamResult((static function () use ($citations): \Generator {
+            yield ['citations' => $citations];
+            yield 'Hello World';
+        })());
+
+        $streamResult->addListener(new StreamListener());
+
+        $chunks = iterator_to_array($streamResult->getContent());
+
+        $this->assertSame(['Hello World'], $chunks);
+        $this->assertTrue($streamResult->getMetadata()->has('citations'));
+        $this->assertSame($citations, $streamResult->getMetadata()->get('citations'));
+    }
+
+    public function testNonArrayChunksAreNotProcessed()
+    {
+        $streamResult = new StreamResult((static function (): \Generator {
+            yield 'Hello ';
+            yield 'World';
+        })());
+
+        $streamResult->addListener(new StreamListener());
+
+        $chunks = iterator_to_array($streamResult->getContent());
+
+        $this->assertSame(['Hello ', 'World'], $chunks);
+        $this->assertFalse($streamResult->getMetadata()->has('search_results'));
+        $this->assertFalse($streamResult->getMetadata()->has('citations'));
+    }
+
+    public function testBothSearchResultsAndCitationsAreProcessed()
+    {
+        $searchResults = [['url' => 'https://example.com']];
+        $citations = ['https://example.com/1'];
+        $streamResult = new StreamResult((static function () use ($searchResults, $citations): \Generator {
+            yield ['search_results' => $searchResults];
+            yield 'Content';
+            yield ['citations' => $citations];
+        })());
+
+        $streamResult->addListener(new StreamListener());
+
+        $chunks = iterator_to_array($streamResult->getContent());
+
+        $this->assertSame(['Content'], $chunks);
+        $this->assertSame($searchResults, $streamResult->getMetadata()->get('search_results'));
+        $this->assertSame($citations, $streamResult->getMetadata()->get('citations'));
+    }
+}