added optional web component UI control

tests/RenderCadenceCompositorHttpControlServerTests.cpp

@@ -157,6 +157,53 @@ void TestRootServesUiIndex()
 	std::filesystem::remove_all(root);
 }
 
+void TestShaderAssetEndpointUsesCallback()
+{
+	using namespace RenderCadenceCompositor;
+
+	const std::filesystem::path root = std::filesystem::temp_directory_path() / "render-cadence-compositor-shader-asset-test";
+	std::filesystem::create_directories(root / "ui");
+	const std::filesystem::path assetPath = root / "ui" / "controls.js";
+	{
+		std::ofstream output(assetPath, std::ios::binary);
+		output << "customElements.define('solid-controls', class extends HTMLElement {});";
+	}
+
+	HttpControlServer server;
+	RenderCadenceHttpRouteCallbacks callbacks;
+	callbacks.resolveShaderAssetPath = [&assetPath](const std::string& shaderId, const std::string& relativePath, std::filesystem::path& resolvedPath, std::string&) {
+		ExpectEquals(shaderId, "solid", "shader asset callback receives shader id");
+		ExpectEquals(relativePath, "ui/controls.js", "shader asset callback receives package-relative asset path");
+		resolvedPath = assetPath;
+		return true;
+	};
+
+	HttpControlServer::HttpRequest request;
+	request.method = "GET";
+	request.path = "/shader-assets/solid/ui/controls.js";
+
+	const HttpControlServer::HttpResponse response = RouteRenderCadenceHttpRequest(request, server, callbacks);
+	ExpectEquals(response.status, "200 OK", "shader asset endpoint serves resolved asset");
+	ExpectEquals(response.contentType, "text/javascript", "shader asset endpoint guesses javascript content type");
+	Expect(response.body.find("solid-controls") != std::string::npos, "shader asset endpoint returns asset body");
+
+	std::filesystem::remove_all(root);
+}
+
+void TestIncompleteShaderAssetEndpointReturns404()
+{
+	using namespace RenderCadenceCompositor;
+
+	HttpControlServer server;
+	HttpControlServer::HttpRequest request;
+	request.method = "GET";
+	request.path = "/shader-assets/solid";
+
+	RenderCadenceHttpRouteCallbacks callbacks;
+	const HttpControlServer::HttpResponse response = RouteRenderCadenceHttpRequest(request, server, callbacks);
+	ExpectEquals(response.status, "404 Not Found", "incomplete shader asset endpoint returns 404");
+}
+
 void TestKnownPostEndpointReturnsActionError()
 {
 	using namespace RenderCadenceCompositor;
@@ -285,6 +332,8 @@ int main()
 	TestNdiSourcesEndpointUsesCallback();
 	TestWebSocketAcceptKey();
 	TestRootServesUiIndex();
+	TestShaderAssetEndpointUsesCallback();
+	TestIncompleteShaderAssetEndpointReturns404();
 	TestKnownPostEndpointReturnsActionError();
 	TestLayerPostEndpointsUseCallbacks();
 	TestGenericPostCallbackHandlesControlRoutes();