import { describe, expect, it, vi } from "vitest"; import { resolveDesktopBackendPort } from "./backendPort"; describe("resolveDesktopBackendPort", () => {  it("returns the starting port when it is available", async () => {    const canListenOnHost = vi.fn(async (port: number) => port === 3773);     await expect(      resolveDesktopBackendPort({        host: "127.0.0.1",        startPort: 3773,        canListenOnHost,      }),    ).resolves.toBe(3773);     expect(canListenOnHost).toHaveBeenCalledTimes(1);    expect(canListenOnHost).toHaveBeenCalledWith(3773, "127.0.0.1");  });   it("increments sequentially until it finds an available port", async () => {    const canListenOnHost = vi.fn(async (port: number) => port === 3775);     await expect(      resolveDesktopBackendPort({        host: "127.0.0.1",        startPort: 3773,        canListenOnHost,      }),    ).resolves.toBe(3775);     expect(canListenOnHost.mock.calls).toEqual([      [3773, "127.0.0.1"],      [3774, "127.0.0.1"],      [3775, "127.0.0.1"],    ]);  });   it("fails when the scan range is exhausted", async () => {    const canListenOnHost = vi.fn(async () => false);     await expect(      resolveDesktopBackendPort({        host: "127.0.0.1",        startPort: 65534,        maxPort: 65535,        canListenOnHost,      }),    ).rejects.toThrow("No desktop backend port is available on 127.0.0.1 between 65534 and 65535");     expect(canListenOnHost.mock.calls).toEqual([      [65534, "127.0.0.1"],      [65535, "127.0.0.1"],    ]);  });});