refactor: item 29 cleanup

F16 F17 F18 F19 F20 F21: import polling backs off and pauses in a hidden tab, one date format module, fake timers in the import tests, error codes instead of raw messages, one safe storage wrapper, dead code.

src/pages/ImportPage.test.jsx

@@ -1,6 +1,6 @@
 // @vitest-environment jsdom
 import {afterEach, beforeEach, describe, expect, it, vi} from 'vitest';
-import {cleanup, fireEvent, render, screen, waitFor, within} from '@testing-library/react';
+import {act, cleanup, fireEvent, render, screen, waitFor, within} from '@testing-library/react';
 import {MemoryRouter, Route, Routes} from 'react-router-dom';
 import {toast} from 'sonner';
 import ImportPage from './ImportPage.jsx';
@@ -49,13 +49,17 @@ function renderPage(routes, entry = '/import') {
 }
 
 const posted = (method, path) => fetch.mock.calls.find(([url, init]) => init?.method === method && url.endsWith(path));
+const polls = (path) => fetch.mock.calls.filter(([url, init]) => !init?.method && url.endsWith(path)).length;
+const wait = (ms) => act(() => vi.advanceTimersByTimeAsync(ms));
 
 beforeEach(() => {
+    vi.useFakeTimers({shouldAdvanceTime: true});
     localStorage.setItem('tbp_session', '1');
 });
 
 afterEach(() => {
     cleanup();
+    vi.useRealTimers();
     localStorage.clear();
     vi.clearAllMocks();
 });
@@ -138,7 +142,8 @@ describe('ImportPage', () => {
         });
 
         expect(await screen.findByText('IMPORT.MATCHING')).toBeTruthy();
-        expect(await screen.findByText('IMPORT.LINE: Hades', {}, {timeout: 3000})).toBeTruthy();
+        await wait(2000);
+        expect(await screen.findByText('IMPORT.LINE: Hades')).toBeTruthy();
     });
 
     it('preselects the favorite, checks only sure matches, and saves the checked lines', async () => {
@@ -240,8 +245,10 @@ describe('ImportPage', () => {
             'GET /5': () => (++polls > 1 ? json(200, ready) : json(200, matching)),
         });
 
-        expect(await screen.findByText('IMPORT.LINE: Hades', {}, {timeout: 4000})).toBeTruthy();
-    }, 10000);
+        await screen.findByText('IMPORT.MATCHING');
+        await wait(2000);
+        expect(await screen.findByText('IMPORT.LINE: Hades')).toBeTruthy();
+    });
 
     it('keeps polling after a 502 while Core restarts', async () => {
         let calls = 0;
@@ -251,8 +258,51 @@ describe('ImportPage', () => {
                 total: 4, matched: 1, chosen: 0, saved: 0, added: 0, ahead: null, attempts: 0})),
         }, '/import?id=8');
 
-        expect(await screen.findByText('IMPORT.MATCHING', {}, {timeout: 4000})).toBeTruthy();
-    }, 10000);
+        await waitFor(() => expect(polls('/8')).toBe(1));
+        await wait(4000);
+        expect(await screen.findByText('IMPORT.MATCHING')).toBeTruthy();
+    });
+
+    it('stops polling after repeated 500', async () => {
+        renderPage({'GET ': json(200, {imports: []}), 'GET /8': json(500, null)}, '/import?id=8');
+
+        await waitFor(() => expect(polls('/8')).toBe(1));
+        await wait(10 * 30_000);
+        expect(screen.getByText('IMPORT.LOAD_FAILED')).toBeTruthy();
+        expect(polls('/8')).toBe(10);
+        await wait(60_000);
+        expect(polls('/8')).toBe(10);
+    });
+
+    it('doubles the delay after each failure', async () => {
+        renderPage({'GET ': json(200, {imports: []}), 'GET /8': json(503, null)}, '/import?id=8');
+
+        await waitFor(() => expect(polls('/8')).toBe(1));
+        await wait(3500);
+        expect(polls('/8')).toBe(1);
+        await wait(1000);
+        expect(polls('/8')).toBe(2);
+        await wait(7000);
+        expect(polls('/8')).toBe(2);
+        await wait(1500);
+        expect(polls('/8')).toBe(3);
+    });
+
+    it('pauses polling in a hidden tab and goes on when it is visible again', async () => {
+        const hidden = vi.spyOn(document, 'hidden', 'get').mockReturnValue(true);
+        renderPage({'GET ': json(200, {imports: []}), 'GET /9': json(200, {id: 9, source: 'TEXT', status: 'MATCHING',
+            total: 2, matched: 1})}, '/import?id=9');
+
+        await screen.findByText('IMPORT.MATCHING');
+        await wait(20_000);
+        expect(polls('/9')).toBe(1);
+
+        hidden.mockReturnValue(false);
+        await act(async () => document.dispatchEvent(new Event('visibilitychange')));
+        expect(polls('/9')).toBe(2);
+        await wait(2000);
+        expect(polls('/9')).toBe(3);
+    });
 });
 
 describe('review findings', () => {
@@ -271,7 +321,7 @@ describe('review findings', () => {
             </MemoryRouter>,
         );
 
-        expect(await screen.findByLabelText('IMPORT.LINE: Hades', {}, {timeout: 2000})).toBeTruthy();
+        expect(await screen.findByLabelText('IMPORT.LINE: Hades')).toBeTruthy();
     });
 });