refactor: drop unused McpApps::isUiResource helper

The helper was only referenced by its own tests — no caller in src/
or examples/ uses it. Server-side code building UI resources already
knows their URI and MIME type, so the helper is YAGNI.

Author: chr-hertel

src/Schema/Extension/Apps/McpApps.php

@@ -12,7 +12,6 @@
 namespace Mcp\Schema\Extension\Apps;
 
 use Mcp\Schema\Extension\ServerExtensionInterface;
-use Mcp\Schema\Resource;
 
 /**
  * The MCP Apps extension (io.modelcontextprotocol/ui).
@@ -44,13 +43,4 @@ public function getCapabilities(): array
     {
         return ['mimeTypes' => [self::MIME_TYPE]];
     }
-
-    /**
-     * Checks whether a Resource is a UI resource based on its URI scheme and MIME type.
-     */
-    public static function isUiResource(Resource $resource): bool
-    {
-        return str_starts_with($resource->uri, self::URI_SCHEME.'://')
-            && self::MIME_TYPE === $resource->mimeType;
-    }
 }

src/Server/Builder.php

@@ -592,24 +592,9 @@ public function build(): Server
             promptsListChanged: $this->eventDispatcher instanceof EventDispatcherInterface,
             logging: true,
             completions: true,
+            extensions: [] !== $this->extensions ? $this->extensions : null,
         );
 
-        if ([] !== $this->extensions) {
-            $capabilities = new ServerCapabilities(
-                tools: $capabilities->tools,
-                toolsListChanged: $capabilities->toolsListChanged,
-                resources: $capabilities->resources,
-                resourcesSubscribe: $capabilities->resourcesSubscribe,
-                resourcesListChanged: $capabilities->resourcesListChanged,
-                prompts: $capabilities->prompts,
-                promptsListChanged: $capabilities->promptsListChanged,
-                logging: $capabilities->logging,
-                completions: $capabilities->completions,
-                experimental: $capabilities->experimental,
-                extensions: array_merge($capabilities->extensions ?? [], $this->extensions),
-            );
-        }
-
         $serverInfo = $this->serverInfo ?? new Implementation();
         $configuration = new Configuration($serverInfo, $capabilities, $this->paginationLimit, $this->instructions, $this->protocolVersion);
         $referenceHandler = $this->referenceHandler ?? new ReferenceHandler($container);

tests/Unit/Schema/Extension/Apps/McpAppsTest.php

@@ -17,7 +17,6 @@
 use Mcp\Schema\Extension\Apps\UiResourceCsp;
 use Mcp\Schema\Extension\Apps\UiResourcePermissions;
 use Mcp\Schema\Extension\Apps\UiToolMeta;
-use Mcp\Schema\Resource;
 use PHPUnit\Framework\TestCase;
 
 class McpAppsTest extends TestCase
@@ -30,39 +29,6 @@ public function testServerExtensionInterface(): void
         $this->assertSame(['mimeTypes' => ['text/html;profile=mcp-app']], $extension->getCapabilities());
     }
 
-    public function testIsUiResourceReturnsTrueForUiResource(): void
-    {
-        $resource = new Resource(
-            uri: 'ui://my-app',
-            name: 'my-app',
-            mimeType: McpApps::MIME_TYPE,
-        );
-
-        $this->assertTrue(McpApps::isUiResource($resource));
-    }
-
-    public function testIsUiResourceReturnsFalseForNonUiScheme(): void
-    {
-        $resource = new Resource(
-            uri: 'file://my-app',
-            name: 'my-app',
-            mimeType: McpApps::MIME_TYPE,
-        );
-
-        $this->assertFalse(McpApps::isUiResource($resource));
-    }
-
-    public function testIsUiResourceReturnsFalseForNonUiMimeType(): void
-    {
-        $resource = new Resource(
-            uri: 'ui://my-app',
-            name: 'my-app',
-            mimeType: 'text/html',
-        );
-
-        $this->assertFalse(McpApps::isUiResource($resource));
-    }
-
     public function testUiResourceCspSerialization(): void
     {
         $csp = new UiResourceCsp(