fix Gemini 3 function call

Author: ilvalerione

src/Providers/Gemini/Gemini.php

@@ -96,6 +96,7 @@ protected function createToolCallMessage(array $message): Message
                 return null;
             }
 
+            // https://ai.google.dev/gemini-api/docs/thought-signatures
             if ($item['thoughtSignature'] ?? false) {
                 $signature = $item['thoughtSignature'];
             }
@@ -106,7 +107,7 @@ protected function createToolCallMessage(array $message): Message
                 ->setCallId($item['functionCall']['name']);
         }, $message['parts']);
 
-        // array_values() reindexes so tools are always a 0-based sequential array,
+        // array_values() reindex so tools are always a 0-based sequential array,
         // even when text/thought parts precede functionCall parts.
         $result = new ToolCallMessage(
             $message['content'] ?? null,

src/Providers/Gemini/HandleChat.php

@@ -21,6 +21,8 @@
 use function json_encode;
 use function trim;
 use function str_starts_with;
+use function array_filter;
+use function count;
 
 trait HandleChat
 {
@@ -93,16 +95,9 @@ public function chatAsync(array $messages): PromiseInterface
 
                 $parts = $content['parts'];
 
-                // Scan ALL parts for functionCall, not just parts[0].
-                // Gemini 3 models may return text or thought parts before functionCall parts.
-                // See https://ai.google.dev/gemini-api/docs/thought-signatures
-                $hasFunctionCall = false;
-                foreach ($parts as $part) {
-                    if (array_key_exists('functionCall', $part) && !empty($part['functionCall'])) {
-                        $hasFunctionCall = true;
-                        break;
-                    }
-                }
+                $hasFunctionCall = count(
+                    array_filter($parts, fn (array $part): bool => !empty($part['functionCall'] ?? null))
+                ) > 0;
 
                 if ($hasFunctionCall) {
                     $response = $this->createToolCallMessage($content);

tests/Providers/GeminiTest.php

@@ -18,6 +18,7 @@
 use NeuronAI\Providers\Gemini\Gemini;
 use NeuronAI\Tools\PropertyType;
 use NeuronAI\Tools\Tool;
+use NeuronAI\Tools\ToolInterface;
 use NeuronAI\Tools\ToolProperty;
 use PHPUnit\Framework\TestCase;
 
@@ -538,7 +539,7 @@ public function test_function_call_with_thought_signature(): void
         $this->assertSame('sig-abc123', $response->getMetadata('thoughtSignature'));
     }
 
-    private function makeSimpleTool(string $name): Tool
+    private function makeSimpleTool(string $name): ToolInterface
     {
         return Tool::make($name, "A test tool called {$name}.")
             ->addProperty(new ToolProperty('prop', PropertyType::STRING, 'A test property', true))