Merge pull request 'fix(search): stop replaying a failed LA-averages request forever' (#178) from fix/la-average-cached-failure into main

Reviewed-on: #178

nextjs-app/__tests__/components/HomeView.staleFetch.test.tsx

@@ -1,6 +1,6 @@
 import { act, fireEvent, render, screen } from '@testing-library/react';
 import { HomeView } from '@/components/HomeView';
-import { fetchSchools } from '@/lib/api';
+import { fetchLAaverages, fetchSchools } from '@/lib/api';
 import { primaryFixture } from '../support/schoolFixtures';
 import type { SchoolsResponse, School } from '@/lib/types';
 
@@ -84,3 +84,23 @@ test('failed map requests can be retried by reopening the map', async () => {
   expect(fetchSchools).toHaveBeenCalledTimes(2);
   expect(screen.getByTestId('map')).toHaveTextContent('Retry result');
 });
+
+test('LA averages are not fetched with force-cache, so one failure is not replayed for good', async () => {
+  // force-cache serves any stored response, however old, without asking the
+  // server. A request that failed once (a staging deploy restart, the July
+  // proxy outage) was stored and replayed on every later visit, and the
+  // "vs LA avg" delta vanished from every secondary row in that browser.
+  // The default mode honours the API's Cache-Control and never reuses an
+  // error.
+  params = new URLSearchParams('search=high');
+  const secondary: SchoolsResponse = {
+    ...response('Alpha High'),
+    schools: [{ ...primaryFixture.schoolInfo, school_name: 'Alpha High', phase: 'Secondary', attainment_8_score: 50 }],
+  };
+  render(<HomeView initialSchools={secondary} filters={filters} />);
+  await act(async () => {});
+  expect(fetchLAaverages).toHaveBeenCalled();
+  for (const [options] of jest.mocked(fetchLAaverages).mock.calls) {
+    expect(options?.cache).not.toBe('force-cache');
+  }
+});