feat(blog): limit rapid repeat views

www/tools/counters.test.mjs

@@ -5,10 +5,12 @@ import test from 'node:test';
 import fg from 'fast-glob';
 import matter from 'gray-matter';
 import {
+  articleViewCooldownMs,
   bindLiveCounters,
   fetchCounterStats,
   readLikedSlugs,
   reportArticleView,
+  reserveArticleView,
   updateLike,
 } from '../src/scripts/likes-views.ts';
 
@@ -139,6 +141,41 @@ test('one article navigation increments once while cards only retrieve statistic
   assert.deepEqual([...readLikedSlugs(storage)], []);
 });
 
+test('a short per-tab cooldown suppresses back-navigation duplicates and then expires', async () => {
+  const likeStorage = new FakeStorage();
+  const viewStorage = new FakeStorage();
+  const calls = [];
+  const fetcher = async (url) => {
+    calls.push(url);
+    return response(url.endsWith('/views')
+      ? { views: 21 }
+      : { 'shared-slug': { likes: 4, views: 20 } });
+  };
+
+  await bindLiveCounters(new FakeRoot([new FakeCounter('shared-slug', { trackView: true })]), fetcher, likeStorage, viewStorage);
+  await bindLiveCounters(new FakeRoot([new FakeCounter('shared-slug', { trackView: true })]), fetcher, likeStorage, viewStorage);
+  assert.equal(calls.filter((url) => url.endsWith('/views')).length, 1);
+
+  const clockStorage = new FakeStorage();
+  assert.equal(reserveArticleView('shared-slug', clockStorage, 10_000), true);
+  assert.equal(reserveArticleView('shared-slug', clockStorage, 10_000 + articleViewCooldownMs - 1), false);
+  assert.equal(reserveArticleView('shared-slug', clockStorage, 10_000 + articleViewCooldownMs), true);
+  assert.equal(reserveArticleView('different-slug', clockStorage, 10_000 + articleViewCooldownMs), true);
+});
+
+test('invalid or unavailable session storage fails open without persisting an identifier', () => {
+  const corrupt = new FakeStorage();
+  corrupt.setItem('aia-view-cooldowns-v1', '{broken');
+  assert.equal(reserveArticleView('article', corrupt, 10_000), true);
+  assert.deepEqual(JSON.parse(corrupt.getItem('aia-view-cooldowns-v1')), { article: 10_000 });
+
+  const blocked = {
+    getItem() { throw new Error('blocked'); },
+    setItem() { throw new Error('blocked'); },
+  };
+  assert.equal(reserveArticleView('article', blocked, 10_000), true);
+});
+
 test('API failures preserve rendering and expose localized inline status', async () => {
   const counter = new FakeCounter('article', { trackView: true, lang: 'ar' });
   const root = new FakeRoot([counter]);