test: data router, one render helper, fetchRoutes in every test

src/pages/StatsPage.test.jsx

@@ -4,10 +4,11 @@ import {cleanup, fireEvent, render, screen, waitFor} from '@testing-library/reac
 import {MemoryRouter} from 'react-router-dom';
 import StatsPage from './StatsPage.jsx';
 import {PreferencesProvider} from '../context/PreferencesContext.jsx';
+import {fetchRoutes, json} from '../test/fetchRoutes.js';
 
 vi.mock('react-i18next', () => import('../test/i18n-mock.js'));
 
-const json = (body, status = 200) => ({ok: status < 400, status, json: async () => body});
+const answerStats = (answer) => fetchRoutes({'GET /api/library/stats': answer});
 
 const stats = (extra = {}) => ({
     overview: {totalGames: 12, totalPlaytimeMinutes: 6000, playedGames: 8, neverStarted: 4,
@@ -38,7 +39,7 @@ describe('StatsPage', () => {
     });
 
     it('asks for every group once and shows each of them', async () => {
-        globalThis.fetch = vi.fn(async () => json(stats()));
+        answerStats(json(200, stats()));
         renderPage();
 
         expect(await screen.findByText('STATS.OVERVIEW.TITLE')).toBeTruthy();
@@ -56,7 +57,7 @@ describe('StatsPage', () => {
 
     it('shows the empty texts of a new library', async () => {
         const empty = stats();
-        globalThis.fetch = vi.fn(async () => json({
+        answerStats(json(200, {
             ...empty,
             pile: {...empty.pile, paceWeeks: null, oldestUnplayed: null},
             topGames: {mostPlayed: [], mostLoyal: null},
@@ -77,7 +78,7 @@ describe('StatsPage', () => {
     });
 
     it('offers a retry when the stats could not be loaded', async () => {
-        globalThis.fetch = vi.fn(async () => json({}, 500));
+        answerStats(json(500, {}));
         renderPage();
 
         fireEvent.click(await screen.findByRole('button', {name: /DASHBOARD.RETRY/}));