From 90177f1645bf886a2e4f84f4db287ba379f01773 Mon Sep 17 00:00:00 2001 From: Claude Date: Tue, 17 Feb 2026 16:35:56 +0000 Subject: fix: store sentinel IntersectionObserver in module-level variable to prevent GC MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The load-more sentinel observer was assigned to a local `const observer` that fell out of scope after renderItems() returned. Without a persistent JS reference, engines can garbage-collect the observer, silently breaking infinite scroll (no more items loaded on scroll). Fix: assign to the existing module-level `itemObserver` variable, which is already disconnected/replaced at the top of each renderItems() call. Add three regression tests in regression.test.ts that use a class-based IntersectionObserver mock to capture the callback and verify: - sentinel visible → loadMore fires - sentinel visible while loading → loadMore suppressed - hasMore=false → no sentinel rendered, no loadMore https://claude.ai/code/session_01DpWhB9uGGMBnzqS28HxnuV --- frontend-vanilla/src/main.ts | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'frontend-vanilla/src/main.ts') diff --git a/frontend-vanilla/src/main.ts b/frontend-vanilla/src/main.ts index 5f8056c..bdd0e97 100644 --- a/frontend-vanilla/src/main.ts +++ b/frontend-vanilla/src/main.ts @@ -270,15 +270,15 @@ export function renderItems() { // Use the actual scroll container as IntersectionObserver root const scrollRoot = document.getElementById('main-content'); - // Setup infinite scroll + // Setup infinite scroll — stored in itemObserver so it has a GC root and won't be collected const sentinel = document.getElementById('load-more-sentinel'); if (sentinel) { - const observer = new IntersectionObserver((entries) => { + itemObserver = new IntersectionObserver((entries) => { if (entries[0].isIntersecting && !store.loading && store.hasMore) { loadMore(); } }, { root: scrollRoot, threshold: 0.1 }); - observer.observe(sentinel); + itemObserver.observe(sentinel); } // Scroll listener for reading items -- cgit v1.2.3