storybook-mcp

import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";

const mockStartStdio = vi.fn();
const StorybookMCPServerMock = vi.fn().mockImplementation(() => ({
  startStdio: mockStartStdio,
}));

vi.mock("../src/server.js", () => ({
  StorybookMCPServer: StorybookMCPServerMock,
}));

describe("CLI entrypoint", () => {
  let exitSpy: ReturnType<typeof vi.spyOn>;
  let errorSpy: ReturnType<typeof vi.spyOn>;

  beforeEach(() => {
    vi.resetModules();
    mockStartStdio.mockReset();
    StorybookMCPServerMock.mockClear();
    exitSpy = vi.spyOn(process, "exit").mockImplementation(
      ((code?: number) => {
        return undefined as never;
      }) as never
    );
    errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
  });

  afterEach(() => {
    exitSpy.mockRestore();
    errorSpy.mockRestore();
  });

  it("starts the MCP server successfully", async () => {
    mockStartStdio.mockResolvedValueOnce(undefined);
    await import("../src/index.js");
    expect(StorybookMCPServerMock).toHaveBeenCalledTimes(1);
    expect(mockStartStdio).toHaveBeenCalledTimes(1);
    expect(exitSpy).not.toHaveBeenCalled();
    expect(errorSpy).not.toHaveBeenCalled();
  });

  it("logs and exits when startup fails", async () => {
    const failure = new Error("boom");
    mockStartStdio.mockRejectedValueOnce(failure);
    await import("../src/index.js");
    expect(errorSpy).toHaveBeenCalledWith(
      "Failed to start Storybook MCP Server:",
      failure
    );
    expect(exitSpy).toHaveBeenCalledWith(1);
  });
});