import { describe, it, expect, vi, beforeEach } from "vitest";
import { navigateBack } from "./navigation";

const goto = vi.fn();
vi.mock("$app/navigation", () => ({
  goto: (...args: unknown[]) => goto(...args),
}));

describe("navigateBack", () => {
  beforeEach(() => {
    goto.mockClear();
  });

  it("pops real history when there is in-app history to go back to", () => {
    const back = vi.fn();
    vi.spyOn(history, "back").mockImplementation(back);
    vi.spyOn(history, "length", "get").mockReturnValue(3);

    navigateBack("/library");

    expect(back).toHaveBeenCalledOnce();
    expect(goto).not.toHaveBeenCalled();
  });

  it("falls back to the given path on a fresh deep-link (no history)", () => {
    const back = vi.fn();
    vi.spyOn(history, "back").mockImplementation(back);
    vi.spyOn(history, "length", "get").mockReturnValue(1);

    navigateBack("/library/music");

    expect(goto).toHaveBeenCalledWith("/library/music");
    expect(back).not.toHaveBeenCalled();
  });
});