[Platform][Anthropic] Fix TypeError in AssistantMessageNormalizer when toolCalls is null

src/platform/src/Bridge/Anthropic/Contract/AssistantMessageNormalizer.php

@@ -26,22 +26,12 @@ final class AssistantMessageNormalizer extends ModelContractNormalizer implement
 {
     use NormalizerAwareTrait;
 
-    protected function supportedDataClass(): string
-    {
-        return AssistantMessage::class;
-    }
-
-    protected function supportsModel(Model $model): bool
-    {
-        return $model instanceof Claude;
-    }
-
     /**
      * @param AssistantMessage $data
      *
      * @return array{
      *     role: 'assistant',
-     *     content: list<array{
+     *     content: string|list<array{
      *         type: 'tool_use',
      *         id: string,
      *         name: string,
@@ -53,14 +43,24 @@ public function normalize(mixed $data, ?string $format = null, array $context =
     {
         return [
             'role' => 'assistant',
-            'content' => array_map(static function (ToolCall $toolCall) {
+            'content' => $data->hasToolCalls() ? array_map(static function (ToolCall $toolCall) {
                 return [
                     'type' => 'tool_use',
                     'id' => $toolCall->id,
                     'name' => $toolCall->name,
                     'input' => [] !== $toolCall->arguments ? $toolCall->arguments : new \stdClass(),
                 ];
-            }, $data->toolCalls),
+            }, $data->toolCalls) : $data->content,
         ];
     }
+
+    protected function supportedDataClass(): string
+    {
+        return AssistantMessage::class;
+    }
+
+    protected function supportsModel(Model $model): bool
+    {
+        return $model instanceof Claude;
+    }
 }

src/platform/tests/Bridge/Anthropic/Contract/AssistantMessageNormalizerTest.php

@@ -0,0 +1,113 @@
+<?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\Anthropic\Contract;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\Attributes\Small;
+use PHPUnit\Framework\Attributes\UsesClass;
+use PHPUnit\Framework\TestCase;
+use Symfony\AI\Platform\Bridge\Anthropic\Claude;
+use Symfony\AI\Platform\Bridge\Anthropic\Contract\AssistantMessageNormalizer;
+use Symfony\AI\Platform\Contract;
+use Symfony\AI\Platform\Message\AssistantMessage;
+use Symfony\AI\Platform\Model;
+use Symfony\AI\Platform\Result\ToolCall;
+
+#[Small]
+#[CoversClass(AssistantMessageNormalizer::class)]
+#[UsesClass(Claude::class)]
+#[UsesClass(AssistantMessage::class)]
+#[UsesClass(Model::class)]
+#[UsesClass(ToolCall::class)]
+final class AssistantMessageNormalizerTest extends TestCase
+{
+    public function testSupportsNormalization()
+    {
+        $normalizer = new AssistantMessageNormalizer();
+
+        $this->assertTrue($normalizer->supportsNormalization(new AssistantMessage('Hello'), context: [
+            Contract::CONTEXT_MODEL => new Claude(),
+        ]));
+        $this->assertFalse($normalizer->supportsNormalization('not an assistant message'));
+    }
+
+    public function testGetSupportedTypes()
+    {
+        $normalizer = new AssistantMessageNormalizer();
+
+        $this->assertSame([AssistantMessage::class => true], $normalizer->getSupportedTypes(null));
+    }
+
+    #[DataProvider('normalizeDataProvider')]
+    public function testNormalize(AssistantMessage $message, array $expectedOutput)
+    {
+        $normalizer = new AssistantMessageNormalizer();
+
+        $normalized = $normalizer->normalize($message);
+
+        $this->assertEquals($expectedOutput, $normalized);
+    }
+
+    /**
+     * @return iterable<string, array{
+     *     0: AssistantMessage,
+     *     1: array{
+     *         role: 'assistant',
+     *         content: string|list<array{
+     *             type: 'tool_use',
+     *             id: string,
+     *             name: string,
+     *             input: array<string, mixed>|\stdClass
+     *         }>
+     *     }
+     * }>
+     */
+    public static function normalizeDataProvider(): iterable
+    {
+        yield 'assistant message' => [
+            new AssistantMessage('Great to meet you. What would you like to know?'),
+            [
+                'role' => 'assistant',
+                'content' => 'Great to meet you. What would you like to know?',
+            ],
+        ];
+        yield 'function call' => [
+            new AssistantMessage(toolCalls: [new ToolCall('id1', 'name1', ['arg1' => '123'])]),
+            [
+                'role' => 'assistant',
+                'content' => [
+                    [
+                        'type' => 'tool_use',
+                        'id' => 'id1',
+                        'name' => 'name1',
+                        'input' => ['arg1' => '123'],
+                    ],
+                ],
+            ],
+        ];
+        yield 'function call without parameters' => [
+            new AssistantMessage(toolCalls: [new ToolCall('id1', 'name1')]),
+            [
+                'role' => 'assistant',
+                'content' => [
+                    [
+                        'type' => 'tool_use',
+                        'id' => 'id1',
+                        'name' => 'name1',
+                        'input' => new \stdClass(),
+                    ],
+                ],
+            ],
+        ];
+    }
+}