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

e2e/tests/journeys.spec.ts

@@ -410,6 +410,29 @@ test('search and the school page agree on how many pupils a secondary has', asyn
   expect(school.total_pupils).toBe(detail.school_info.total_pupils);
 });
 
+test('a secondary search row compares its Attainment 8 with the LA average', async ({ page }) => {
+  // The comparison vanished unnoticed: the averages were fetched with
+  // force-cache, so one stored failure hid it in that browser for good.
+  // Playwright disables the HTTP cache when it intercepts requests, so this
+  // guards the comparison itself; the unit test pins the cache mode.
+  const la = await (await page.request.get('/api/la-averages')).json();
+  const averages: Record<string, number> = la.secondary?.attainment_8_by_la ?? {};
+  const res = await page.request.get('/api/schools?search=school&phase=secondary&page_size=50');
+  expect(res.ok()).toBeTruthy();
+  const school = ((await res.json()).schools ?? []).find(
+    (s: { attainment_8_score?: number | null; local_authority?: string; school_type?: string }) =>
+      s.attainment_8_score != null && s.local_authority != null && averages[s.local_authority] != null
+      && !/special|pupil referral|alternative provision/i.test(s.school_type ?? ''));
+  test.skip(!school, 'no mainstream secondary with an LA average here');
+
+  await searchByName(page, school.school_name);
+  const link = page.locator(`a[href^="/school/${school.urn}-"]`).first();
+  await expect(link).toBeVisible({ timeout: 15_000 });
+  const stats = link.locator('xpath=ancestor::div[contains(@class, "__rowContent")][1]')
+    .locator('[class*="__line3"]');
+  await expect(stats.getByText(/vs LA avg/)).toBeVisible();
+});
+
 test('a phase outside primary/secondary filters to that phase, not to everything', async ({ page }) => {
   // The search page offers every GIAS phase, but the API only knew the grouped
   // ones and silently dropped the rest — so "Nursery" returned primaries.

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');
+  }
+});

nextjs-app/components/HomeView.tsx

@@ -358,10 +358,14 @@ export function HomeView({ initialSchools, filters, totalSchools, howItWorks, ed
     return () => controller.abort();
   }, [resultsView, searchParams, initialSchools.schools]);
 
-  // Fetch LA averages when secondary or mixed schools are visible
+  // Fetch LA averages when secondary or mixed schools are visible. Default
+  // cache mode, never force-cache: force-cache replays any stored response
+  // without asking the server, so one failed request (a deploy restart) hid
+  // every "vs LA avg" delta in that browser for good. The API's Cache-Control
+  // already lets the browser reuse a good answer for five minutes.
   useEffect(() => {
     if (!isSecondaryView && !isMixedView) return;
-    fetchLAaverages({ cache: 'force-cache' })
+    fetchLAaverages()
       .then(data => setLaAverages(data.secondary.attainment_8_by_la))
       .catch(() => {});
   }, [isSecondaryView, isMixedView]);