siftlode/frontend/src/components/NavigationProvider.dom.test.tsx

// @vitest-environment jsdom
//
// The navigation actions against the overlay history stack: `setPage` and `openChannel` never push
// under an open overlay — they close it and push once its Back-to-close entry is reclaimed — and
// `setPage`'s same-page guard, which decides whether anything is pushed at all.
//
// The overlay half is what used to live at each call site (Shift+W in App, a toast's "View", the
// palette, the player's channel link) and could be forgotten at any of them; it now lives in the two
// actions, so this file is where it is pinned. The end-to-end gesture — Shift+W over the player,
// then browser Back — is still checked in a real browser: jsdom reproduces history ordering only as
// bookkeeping.
import { describe, it, expect, afterEach, beforeEach, vi } from "vitest";
import { renderHook, act, cleanup } from "@testing-library/react";
import type { ReactNode } from "react";

// Partial: the provider reads `t` AND `i18n.language` (both feed the document-title effect), and the
// import graph pulls in `src/i18n`, which initialises against the real `initReactI18next` — so a
// wholesale mock throws before any test runs.
vi.mock("react-i18next", async (importOriginal) => {
  const actual = await importOriginal<typeof import("react-i18next")>();
  return {
    ...actual,
    useTranslation: () => ({ t: (k: string) => k, i18n: { language: "en" } }),
  };
});

import { NavigationProvider, useNavigation, useNavigationActions } from "./NavigationProvider";
import { useBackToClose } from "../lib/history";

const wrapper = ({ children }: { children: ReactNode }) => (
  <NavigationProvider>{children}</NavigationProvider>
);
const render = () =>
  renderHook(() => ({ ...useNavigation(), ...useNavigationActions() }), { wrapper });

const settle = () =>
  act(async () => {
    await new Promise((r) => setTimeout(r, 0));
  });

/** An open overlay (the player) whose close really unmounts it; its reclaiming back() is stubbed to
 *  land its popstate at once. */
async function openOverlay() {
  const back = vi.spyOn(window.history, "back").mockImplementation(() => {
    window.dispatchEvent(new PopStateEvent("popstate", { state: window.history.state }));
  });
  const holder: { unmount?: () => void } = {};
  const onClose = vi.fn(() => holder.unmount?.());
  const layer = renderHook(() => useBackToClose(onClose));
  holder.unmount = layer.unmount;
  await settle();
  return { back, onClose };
}

beforeEach(() => {
  localStorage.clear();
  sessionStorage.setItem("siftlode.activeAccount", "1"); // account-scoped page memory
  window.history.replaceState({ sfPage: "feed" }, "", "/");
});
// Not automatic: vitest runs without `globals`, so RTL never registers its own afterEach — leaving a
// provider (and its popstate listener) mounted for the next case. Same reason Home.dom.test.tsx does.
afterEach(() => {
  cleanup();
  vi.restoreAllMocks();
});

describe("NavigationProvider · setPage's same-page guard", () => {
  it("pushes an entry for a real page change", () => {
    const { result } = render();
    const push = vi.spyOn(window.history, "pushState");
    act(() => result.current.setPage("plex"));
    expect(push).toHaveBeenCalledTimes(1);
    expect(result.current.page).toBe("plex");
  });

  it("pushes nothing when it is already that page", () => {
    const { result } = render();
    act(() => result.current.setPage("plex"));
    const push = vi.spyOn(window.history, "pushState");
    act(() => result.current.setPage("plex"));
    expect(push).not.toHaveBeenCalled();
  });

  it("still navigates to the current page when a channel page is over it", () => {
    // The nav rail's own module while a channel page is open over it is a real navigation: it closes
    // the channel page. The `&& !channelViewRef.current` half of the guard is what makes it one.
    const { result } = render();
    // The page under test must be the one that is ALREADY current, or the guard's first conjunct is
    // false and this never reaches the clause it is named for — the mistake round 4 caught here: a
    // bare URL with cleared storage lands on "home" (navigationInit's E24 default), not "feed", so
    // asking for "feed" was just an ordinary page change and deleting the clause left it green.
    const current = result.current.page;
    expect(current).toBe("home");
    act(() => result.current.openChannel("UC1", "A channel"));
    expect(result.current.channelView).not.toBeNull();

    const push = vi.spyOn(window.history, "pushState");
    act(() => result.current.setPage(current));
    expect(push).toHaveBeenCalledTimes(1);
    expect(result.current.channelView).toBeNull();
  });
});

describe("NavigationProvider · never under an open overlay", () => {
  it("setPage closes the overlay first and pushes only once its entry is reclaimed", async () => {
    const { result } = render();
    const { back, onClose } = await openOverlay();
    const push = vi.spyOn(window.history, "pushState");

    act(() => result.current.setPage("plex"));
    expect(onClose).toHaveBeenCalledTimes(1);
    expect(push).not.toHaveBeenCalled(); // not while the player's entry is still current

    await settle();
    await settle();
    expect(back).toHaveBeenCalledTimes(1);
    expect(push).toHaveBeenCalledTimes(1);
    expect(result.current.page).toBe("plex");
    expect(window.history.state).toMatchObject({ sfPage: "plex" });
  });

  // Shift+W on Home with the player open (owner decision 2026-09-09): nothing to push, but the player
  // closes, and its entry is reclaimed rather than orphaned under a push that never happened.
  it("setPage to the current page closes the overlay and pushes nothing", async () => {
    const { result } = render();
    const { back, onClose } = await openOverlay();
    const push = vi.spyOn(window.history, "pushState");

    act(() => result.current.setPage(result.current.page));
    await settle();
    await settle();
    expect(onClose).toHaveBeenCalledTimes(1);
    expect(back).toHaveBeenCalledTimes(1);
    expect(push).not.toHaveBeenCalled();
  });

  // The player's channel link and the palette's channel rows.
  it("openChannel closes the overlay first and pushes the channel once its entry is reclaimed", async () => {
    const { result } = render();
    const { back, onClose } = await openOverlay();
    const push = vi.spyOn(window.history, "pushState");

    act(() => result.current.openChannel("UC1", "A channel"));
    expect(onClose).toHaveBeenCalledTimes(1);
    expect(push).not.toHaveBeenCalled();

    await settle();
    await settle();
    expect(back).toHaveBeenCalledTimes(1);
    expect(push).toHaveBeenCalledTimes(1);
    expect(result.current.channelView).toEqual({ id: "UC1", name: "A channel" });
    expect(window.history.state).toMatchObject({ _chan: "UC1" });
  });
});