Show configured metrics retention (Refs #141)

tests/unit/metrics-refresh.test.ts

@@ -12,6 +12,7 @@ const emptyMatches = {
 };
 const report = (days: number) => ({
     days,
+    metricsKeepDays: 31,
     now: 1000,
     since: 0,
     summary: totals,
@@ -80,6 +81,13 @@ function setup(fetcher: typeof fetch) {
 }
 
 describe('metrics background refresh', () => {
+    it.each([90, 1, 0])('accepts configured retention of %i days', async (metricsKeepDays) => {
+        const value = { ...report(7), metricsKeepDays };
+        const refresh = setup(vi.fn().mockResolvedValue(Response.json(value)));
+        await refresh.refresh();
+        expect(refresh.onData).toHaveBeenLastCalledWith(value);
+    });
+
     it.each([
         null,
         { ...report(7).autoscaling, added: -1 },
@@ -297,6 +305,10 @@ describe('metrics background refresh', () => {
                 maps: [{ ...value.maps[0], running: { average: 1, peak: 1, capturedHours: null } }]
             },
             { ...value, autoscalingPaused: undefined },
+            ...[undefined, null, '90', -1, 1.5].map((metricsKeepDays) => ({
+                ...value,
+                metricsKeepDays
+            })),
             { ...value, running: undefined },
             { ...value, previous: { ...value.previous, running: undefined } },
             { ...value, maps: [{ ...value.maps[0], policy: { id: 'moon' } }] },

tests/unit/metrics.test.ts

@@ -439,6 +439,23 @@ describe('historical metrics', () => {
         expect(result.summary.playerHours * 3600).toBeCloseTo(30);
     });
 
+    it('updates retention in page loads and refreshes without new samples or cache expiry', async () => {
+        const { fleetSettings, saveFleetSettings } =
+            await import('../../src/lib/server/settings.js');
+        const { GET } = await import('../../src/routes/api/metrics/+server.js');
+        const { load } = await import('../../src/routes/metrics/+page.server.js');
+        vi.spyOn(Date, 'now').mockReturnValue(Date.UTC(2026, 9, 10, 12));
+        const url = new URL('http://localhost/metrics?days=7');
+        const pageData = () => load({ url } as Parameters<typeof load>[0]);
+        expect(await pageData()).toMatchObject({ metricsKeepDays: 31 });
+        for (const metricsKeepDays of [90, 0, 1]) {
+            saveFleetSettings({ ...fleetSettings(), metricsKeepDays });
+            const payload = await (await GET({ url })).json();
+            expect(payload.metricsKeepDays).toBe(metricsKeepDays);
+            expect(payload).toEqual(await pageData());
+        }
+    });
+
     it('shares the range parser and response contract between SSR and the uncached refresh endpoint', async () => {
         const { recordMetrics } = await import('../../src/lib/server/fleet/metrics.js');
         const { GET } = await import('../../src/routes/api/metrics/+server.js');

tests/unit/ui-metrics-page.test.ts

@@ -54,6 +54,7 @@ function report(): MetricsData {
     const summary = { observed: 10, active: 5, idle: 5, unknown: 2, playerHours: 20 };
     return {
         days: 7,
+        metricsKeepDays: 31,
         since: now - 7 * 86400000,
         now,
         firstRetainedSampleAt: now - 14 * 86400000,
@@ -116,6 +117,25 @@ function scope(search: string, stateSearch?: string) {
 }
 beforeEach(() => scope(''));
 
+it.each([
+    [31, 'for 31 days'],
+    [90, 'for 90 days'],
+    [1, 'for 1 day'],
+    [0, 'indefinitely']
+] as const)(
+    'shows configured occupancy retention of %i days in About this report',
+    (metricsKeepDays, expected) => {
+        const body = render(MetricsPage, {
+            props: { data: { ...report(), metricsKeepDays, user: null, setupRequired: false } }
+        })
+            .body.replace(/<!--[\s\S]*?-->/g, '')
+            .replace(/\s+/g, ' ');
+        const about = body.slice(body.indexOf('About this report'));
+        expect(about).toContain(`Occupancy history is retained ${expected};`);
+        expect(about).toContain('saved match retention is configured separately');
+    }
+);
+
 it('shows Provisioning outcomes and readiness with a policy link, even without occupancy', () => {
     const data = report();
     const section = render(MetricsAutoscaling, { props: { metrics: data.autoscaling } }).body;