Fix empty tool list in request is ending in 400 bad request

src/ToolBox/ChainProcessor.php

@@ -29,8 +29,13 @@ public function processInput(Input $input): void
             throw MissingModelSupport::forToolCalling($input->llm::class);
         }
 
+        $toolMap = $this->toolBox->getMap();
+        if ([] === $toolMap) {
+            return;
+        }
+
         $options = $input->getOptions();
-        $options['tools'] = $this->toolBox->getMap();
+        $options['tools'] = $toolMap;
         $input->setOptions($options);
     }
 

tests/ToolBox/ChainProcessorTest.php

@@ -0,0 +1,71 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpLlm\LlmChain\Tests\ToolBox;
+
+use PhpLlm\LlmChain\Chain\Input;
+use PhpLlm\LlmChain\Exception\MissingModelSupport;
+use PhpLlm\LlmChain\LanguageModel;
+use PhpLlm\LlmChain\Message\MessageBag;
+use PhpLlm\LlmChain\ToolBox\ChainProcessor;
+use PhpLlm\LlmChain\ToolBox\ToolBoxInterface;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\Attributes\UsesClass;
+use PHPUnit\Framework\TestCase;
+
+#[CoversClass(ChainProcessor::class)]
+#[UsesClass(Input::class)]
+#[UsesClass(MessageBag::class)]
+#[UsesClass(MissingModelSupport::class)]
+class ChainProcessorTest extends TestCase
+{
+    #[Test]
+    public function processInputWithoutRegisteredToolsWillResultInNoOptionChange(): void
+    {
+        $toolBox = $this->createStub(ToolBoxInterface::class);
+        $toolBox->method('getMap')->willReturn([]);
+
+        $llm = $this->createMock(LanguageModel::class);
+        $llm->method('supportsToolCalling')->willReturn(true);
+
+        $chainProcessor = new ChainProcessor($toolBox);
+        $input = new Input($llm, new MessageBag(), []);
+
+        $chainProcessor->processInput($input);
+
+        self::assertSame([], $input->getOptions());
+    }
+
+    #[Test]
+    public function processInputWithRegisteredToolsWillResultInOptionChange(): void
+    {
+        $toolBox = $this->createStub(ToolBoxInterface::class);
+        $toolBox->method('getMap')->willReturn(['tool1' => 'tool1', 'tool2' => 'tool2']);
+
+        $llm = $this->createMock(LanguageModel::class);
+        $llm->method('supportsToolCalling')->willReturn(true);
+
+        $chainProcessor = new ChainProcessor($toolBox);
+        $input = new Input($llm, new MessageBag(), []);
+
+        $chainProcessor->processInput($input);
+
+        self::assertSame(['tools' => ['tool1' => 'tool1', 'tool2' => 'tool2']], $input->getOptions());
+    }
+
+    #[Test]
+    public function processInputWithUnsupportedToolCallingWillThrowException(): void
+    {
+        $this->expectException(MissingModelSupport::class);
+
+        $llm = $this->createMock(LanguageModel::class);
+        $llm->method('supportsToolCalling')->willReturn(false);
+
+        $chainProcessor = new ChainProcessor($this->createStub(ToolBoxInterface::class));
+        $input = new Input($llm, new MessageBag(), []);
+
+        $chainProcessor->processInput($input);
+    }
+}