Fix ToolChoiceMap producing invalid payloads for Anthropic and Converse schemas

Anthropic schema returned bare strings ('auto'/'any') instead of objects ({'type': 'auto'}). Converse schema nested auto/any under a 'tool' wrapper and used empty arrays instead of stdClass for JSON object serialization.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: wojt-janowski

src/Schemas/Anthropic/Maps/ToolChoiceMap.php

@@ -10,9 +10,9 @@
 class ToolChoiceMap
 {
     /**
-     * @return array<string, mixed>|string|null
+     * @return array<string, mixed>|null
      */
-    public static function map(string|ToolChoice|null $toolChoice): string|array|null
+    public static function map(string|ToolChoice|null $toolChoice): ?array
     {
         if (is_null($toolChoice)) {
             return null;
@@ -30,8 +30,8 @@ public static function map(string|ToolChoice|null $toolChoice): string|array|nul
         }
 
         return match ($toolChoice) {
-            ToolChoice::Auto => 'auto',
-            ToolChoice::Any => 'any',
+            ToolChoice::Auto => ['type' => 'auto'],
+            ToolChoice::Any => ['type' => 'any'],
         };
 
     }

src/Schemas/Converse/Maps/ToolChoiceMap.php

@@ -31,9 +31,7 @@ public static function map(string|ToolChoice|null $toolChoice): string|array|nul
         }
 
         return [
-            'tool' => [
-                ($toolChoice === ToolChoice::Auto ? 'auto' : 'any') => [],
-            ],
+            ($toolChoice === ToolChoice::Auto ? 'auto' : 'any') => new \stdClass,
         ];
     }
 }

tests/Schemas/Anthropic/Maps/ToolChoiceMapTest.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Schemas\Anthropic\Maps;
+
+use InvalidArgumentException;
+use Prism\Bedrock\Schemas\Anthropic\Maps\ToolChoiceMap;
+use Prism\Prism\Enums\ToolChoice;
+
+it('returns null when tool choice is null', function (): void {
+    expect(ToolChoiceMap::map(null))->toBeNull();
+});
+
+it('maps a specific tool correctly', function (): void {
+    expect(ToolChoiceMap::map('search'))
+        ->toBe([
+            'type' => 'tool',
+            'name' => 'search',
+        ]);
+});
+
+it('maps auto tool correctly', function (): void {
+    expect(ToolChoiceMap::map(ToolChoice::Auto))
+        ->toBe(['type' => 'auto']);
+});
+
+it('maps any tool correctly', function (): void {
+    expect(ToolChoiceMap::map(ToolChoice::Any))
+        ->toBe(['type' => 'any']);
+});
+
+it('throws exception for invalid tool choice', function (): void {
+    ToolChoiceMap::map(ToolChoice::None);
+})->throws(InvalidArgumentException::class, 'Invalid tool choice');

tests/Schemas/Converse/Maps/ToolChoiceMapTest.php

@@ -18,18 +18,14 @@
 
 it('maps any tool correctly', function (): void {
     expect(ToolChoiceMap::map(ToolChoice::Any))
-        ->toBe([
-            'tool' => [
-                'any' => [],
-            ],
+        ->toEqual([
+            'any' => new \stdClass,
         ]);
 });
 
 it('maps auto tool correctly', function (): void {
     expect(ToolChoiceMap::map(ToolChoice::Auto))
-        ->toBe([
-            'tool' => [
-                'auto' => [],
-            ],
+        ->toEqual([
+            'auto' => new \stdClass,
         ]);
 });