fix: abort old loads, stale sync state, warn before unsaved edits are lost

src/hooks/useLibrarySync.test.jsx

@@ -0,0 +1,91 @@
+// @vitest-environment jsdom
+import {afterEach, beforeEach, describe, expect, it, vi} from 'vitest';
+import {act, cleanup, renderHook} from '@testing-library/react';
+import useLibrarySync from './useLibrarySync.js';
+import {fetchRoutes, json} from '../test/fetchRoutes.js';
+
+const status = (lastSyncStatus, lastSyncedAt) => json(200, {lastSyncStatus, lastSyncedAt});
+
+beforeEach(() => {
+    vi.useFakeTimers();
+    localStorage.setItem('tbp_session', '1');
+});
+
+afterEach(() => {
+    cleanup();
+    vi.useRealTimers();
+    localStorage.clear();
+});
+
+describe('useLibrarySync', () => {
+    it('shows a sync that runs longer than the poll limit as stale, not as running forever', async () => {
+        const fetch = fetchRoutes({'GET /api/library/sync-status': status('RUNNING', null)});
+        const {result} = renderHook(() => useLibrarySync({enabled: true, onComplete: () => {}}));
+        await act(() => vi.advanceTimersByTimeAsync(0));
+        expect(result.current.isRunning).toBe(true);
+
+        await act(() => vi.advanceTimersByTimeAsync(125_000));
+
+        expect(result.current.isRunning).toBe(false);
+        expect(result.current.stale).toBe(true);
+        const calls = fetch.mock.calls.length;
+        await act(() => vi.advanceTimersByTimeAsync(30_000));
+        expect(fetch.mock.calls.length).toBe(calls);
+    });
+
+    it('after watch() reports the end of a sync once, also when it never saw it running', async () => {
+        let answer = status('OK', '2026-09-30T08:00:00Z');
+        fetchRoutes({'GET /api/library/sync-status': () => answer});
+        const onComplete = vi.fn();
+        const {result} = renderHook(() => useLibrarySync({enabled: true, onComplete}));
+        await act(() => vi.advanceTimersByTimeAsync(0));
+
+        act(() => result.current.watch());
+        await act(() => vi.advanceTimersByTimeAsync(0));
+        // The sync was so fast that the next poll already sees it done.
+        answer = status('OK', '2026-09-30T08:05:00Z');
+        await act(() => vi.advanceTimersByTimeAsync(3_000));
+        await act(() => vi.advanceTimersByTimeAsync(30_000));
+
+        expect(onComplete).toHaveBeenCalledTimes(1);
+    });
+
+    it('reports the end of a running sync once', async () => {
+        let answer = status('RUNNING', '2026-09-30T08:00:00Z');
+        fetchRoutes({'GET /api/library/sync-status': () => answer});
+        const onComplete = vi.fn();
+        const {result} = renderHook(() => useLibrarySync({enabled: true, onComplete}));
+        await act(() => vi.advanceTimersByTimeAsync(0));
+
+        answer = status('FAILED', '2026-09-30T08:01:00Z');
+        await act(() => vi.advanceTimersByTimeAsync(3_000));
+        await act(() => vi.advanceTimersByTimeAsync(30_000));
+
+        expect(onComplete).toHaveBeenCalledTimes(1);
+        expect(result.current.status).toBe('FAILED');
+    });
+
+    it('fires onComplete only once when expectInitialSync flips after the watched run ended', async () => {
+        let answer = status('OK', '2026-09-30T08:00:00Z');
+        fetchRoutes({'GET /api/library/sync-status': () => answer});
+        const onComplete = vi.fn();
+        const {result, rerender} = renderHook(
+            ({expectInitialSync}) => useLibrarySync({enabled: true, expectInitialSync, onComplete}),
+            {initialProps: {expectInitialSync: false}});
+        await act(() => vi.advanceTimersByTimeAsync(0));
+
+        act(() => result.current.watch());
+        await act(() => vi.advanceTimersByTimeAsync(0));
+        answer = status('OK', '2026-09-30T08:05:00Z');
+        await act(() => vi.advanceTimersByTimeAsync(3_000));
+        expect(onComplete).toHaveBeenCalledTimes(1);
+
+        // onComplete loads the list: isLoading goes true and back to false, and with 0 games expectInitialSync follows.
+        rerender({expectInitialSync: true});
+        await act(() => vi.advanceTimersByTimeAsync(0));
+        rerender({expectInitialSync: false});
+        await act(() => vi.advanceTimersByTimeAsync(0));
+
+        expect(onComplete).toHaveBeenCalledTimes(1);
+    });
+});