feat: alert operators on stale data

test/fetch-utils.test.mjs

@@ -1,6 +1,7 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
 import { safeFetch, safeFetchText, getFetchMetrics } from '../apis/utils/fetch.mjs';
+import { formatStaleAlert, shouldSendStaleAlert } from '../lib/stale-alerts.mjs';
 
 test('safeFetch reports HTML as degraded JSON response', async () => {
   const originalFetch = globalThis.fetch;
@@ -34,3 +35,60 @@ test('safeFetchText returns text and byte count', async () => {
     globalThis.fetch = originalFetch;
   }
 });
+
+test('stale alert is skipped for fresh health and resets active key', () => {
+  const state = { lastStaleAlertKey: 'old', lastStaleAlertAt: 100 };
+  const decision = shouldSendStaleAlert({ stale: false }, state, { now: 200 });
+  assert.equal(decision.send, false);
+  assert.equal(decision.reason, 'not_stale');
+  assert.equal(state.lastStaleAlertKey, null);
+});
+
+test('stale alert sends once and deduplicates during cooldown', () => {
+  const state = {};
+  const health = {
+    stale: true,
+    lastSuccessfulSweep: '2026-05-17T08:00:00.000Z',
+    lastSweepError: 'network timeout',
+    sourcesFailed: 2,
+    sourcesDegraded: 1,
+  };
+
+  const first = shouldSendStaleAlert(health, state, { now: 1_000, cooldownMs: 60_000 });
+  const second = shouldSendStaleAlert(health, state, { now: 2_000, cooldownMs: 60_000 });
+
+  assert.equal(first.send, true);
+  assert.equal(second.send, false);
+  assert.equal(second.reason, 'cooldown');
+});
+
+test('stale alert repeats after cooldown', () => {
+  const state = {};
+  const health = { stale: true, lastSuccessfulSweep: 'a', lastSweepError: 'timeout', sourcesFailed: 1 };
+
+  assert.equal(shouldSendStaleAlert(health, state, { now: 1_000, cooldownMs: 60_000 }).send, true);
+  assert.equal(shouldSendStaleAlert(health, state, { now: 62_000, cooldownMs: 60_000 }).send, true);
+});
+
+test('stale alert message includes operator context and affected sources', () => {
+  const message = formatStaleAlert({
+    status: 'stale',
+    stale: true,
+    dataAgeSeconds: 7200,
+    lastSuccessfulSweep: '2026-05-17T08:00:00.000Z',
+    lastSweep: '2026-05-17T10:00:00.000Z',
+    lastSweepError: 'GDELT timeout',
+    sourcesOk: 20,
+    sourcesDegraded: 3,
+    sourcesFailed: 2,
+    sourceHealth: [
+      { name: 'GDELT', status: 'degraded', error: 'timeout' },
+      { name: 'Reddit', status: 'no_credentials' },
+    ],
+  }, { dashboardUrl: 'https://terminal.example.test', context: 'failed sweep' });
+
+  assert.match(message, /CRUCIX STALE DATA ALERT/);
+  assert.match(message, /Data age: 120 minutes/);
+  assert.match(message, /GDELT: degraded \(timeout\)/);
+  assert.match(message, /Dashboard: https:\/\/terminal\.example\.test/);
+});