provideMockMcpUi

provideMockMcpUi(args?: MockMcpUiArgs): ProvideMockMcpUiResult

provideMockMcpUi() gives you the providers that a widget needs, and the MockAdaptor behind them.

import { provideMockMcpUi } from "ng-mcp-ui/testing";

const { providers, adaptor } = provideMockMcpUi({
  hostContext: { theme: "dark" },
  toolResponses: { cast_vote: { total: 4 } },
});

Returns

Member	Type	Purpose
providers	EnvironmentProviders	Pass to your test injector.
adaptor	MockAdaptor	Drive the host and read the call log.

The arguments are the same as the arguments of MockAdaptor.

A canned response with resultType: "input_required" is refused: callTool rejects with an error. A host never surfaces a multi-round trip to a widget, therefore a tool that a view calls has to finish in one round. Keep an elicitation flow on a chat-path tool.

In a test

The providers work in a bare Angular injector. You need no TestBed, and no Zone.js.

const { providers, adaptor } = provideMockMcpUi({ hostContext: { theme: "dark" } });
const injector = createEnvironmentInjector([providers], parentInjector);

const layout = runInInjectionContext(injector, () => injectLayout());
expect(layout().theme).toBe("dark");

adaptor.pushHostContext("theme", "light");
expect(layout().theme).toBe("light");

Each inject* function needs an injection context, therefore wrap the call in runInInjectionContext.

Why it works

Every inject* function reads the MCP_ADAPTOR token, and none of them reads a global. Therefore one provider override replaces the host for the whole widget.

provideMockMcpUi() is a pure function. It touches no window, so it also runs under SSR and in a plain Node test.

Related

• MockAdaptor
• Testing widgets
• provideMcpUi