keep state of aritcle/list view

vue/src/composables/__tests__/useFeeds.spec.js

@@ -13,7 +13,7 @@ class FakeIntersectionObserver {
 vi.stubGlobal('IntersectionObserver', FakeIntersectionObserver)
 
 describe('useFeeds', () => {
-  const { feeds, allItems, feedFilter, feedTitles, unreadCount, setFeedFilter, showMessage, message, showModal, fetchData, sync, getReadable, setInitialLoad, handleIntersection, markAllRead } = useFeeds()
+  const { feeds, allItems, feedFilter, feedTitles, unreadCount, setFeedFilter, showMessage, message, showModal, fetchData, sync, getReadable, setInitialLoad, handleIntersection, markAllRead, setupIntersectionObserver } = useFeeds()
 
   beforeEach(() => {
     localStorage.setItem('user-token', 'test-token')
@@ -119,6 +119,39 @@ describe('useFeeds', () => {
     setInitialLoad(false)
   })
 
+  it('ignores the initial observer snapshot on connect so a scrolled-down reconnect cannot mass-mark', async () => {
+    feeds.value = [
+      { id: 201, title: 'First' },
+      { id: 202, title: 'Second' },
+    ]
+    setInitialLoad(true)
+    axios.put.mockResolvedValue({ status: 200 })
+
+    // A .observe node must exist for setupIntersectionObserver to arm the skip.
+    const node = document.createElement('div')
+    node.className = 'observe'
+    document.body.appendChild(node)
+    setupIntersectionObserver()
+
+    // First callback after connect is the initial snapshot — must be dropped
+    // even though both entries look "scrolled past" (above the topbar).
+    await handleIntersection([
+      { isIntersecting: false, boundingClientRect: { y: -10 }, target: { id: '0' } },
+      { isIntersecting: false, boundingClientRect: { y: -5 }, target: { id: '1' } },
+    ])
+    expect(axios.put).not.toHaveBeenCalled()
+    expect(feeds.value).toHaveLength(2)
+
+    // A genuine later scroll-past still marks read.
+    await handleIntersection([
+      { isIntersecting: false, boundingClientRect: { y: -10 }, target: { id: '0' } },
+    ])
+    expect(axios.put).toHaveBeenCalledWith('/api/v1/article/read/201', null, expect.anything())
+
+    document.body.removeChild(node)
+    setInitialLoad(false)
+  })
+
   describe('feed filter', () => {
     const twoFeedsResponse = {
       data: {

vue/src/composables/useFeeds.js

@@ -34,12 +34,21 @@ const unreadCount = computed(() => {
 })
 const message = ref('')
 const showModal = ref(false)
-const viewMode = ref('list') // 'list' | 'article' — toggled from the hamburger menu
+const viewMode = ref(localStorage.getItem('viewMode') || 'list') // 'list' | 'article' — toggled from the hamburger menu, persisted per device
 const currentIndex = ref(0)
 const layout = ref(localStorage.getItem('layout') || 'list') // 'list' | 'cards' — list-view display style, toggled from the hamburger menu
 
 let observer; // Declare observer outside the setup function
 let initialLoad = false
+// An IntersectionObserver always delivers an initial snapshot for every element
+// it starts observing. If the observer (re)connects while the page is scrolled
+// down — e.g. leaving a scrolled article view, an HMR module reload, or the
+// post-splice re-setup in handleIntersection — that snapshot reports every
+// article above the viewport as "not intersecting / scrolled past" and would
+// mark them all read at once. So each setupIntersectionObserver() sets this and
+// handleIntersection() drops exactly the first callback after a connect; only
+// genuine scroll-driven exits mark read after that.
+let skipNextObservation = false
 
 // Timestamp (performance.now()) of the most recent programmatic scroll / list
 // mutation that moves the page without user intent — currently the list-view
@@ -282,14 +291,25 @@ function setupIntersectionObserver() {
   });
 
   const observedDivs = document.querySelectorAll(".observe");
-  if (observedDivs.length > 0) {
+  // Arm the skip only when we actually observe nodes: an observe() batch fires
+  // an initial snapshot to drop (a connect while scrolled down would otherwise
+  // mass-mark everything above the viewport), but with nothing observed there's
+  // no snapshot — and assigning unconditionally clears any stale flag from a
+  // prior no-op setup (e.g. one run in article view, which has no .observe nodes).
+  skipNextObservation = observedDivs.length > 0
   observedDivs.forEach(observedDiv => {
     observer.observe(observedDiv);
   })
 }
-}
 
 function handleIntersection(entries, topbarHeight = 0) {
+  // Drop the initial snapshot fired on (re)connect — see skipNextObservation.
+  // The old observer is disconnected before this new one observes, so only the
+  // latest observer's initial callback reaches here; one skip is enough.
+  if (skipNextObservation) {
+    skipNextObservation = false
+    return
+  }
   // Resolve all affected feeds before touching feeds.value — the target.id
   // indices are render-time positions that shift once we splice the array.
   const readFeeds = entries
@@ -386,6 +406,7 @@ async function leaveArticleView() {
   allItems.value = allItems.value.filter(feed => !feed.read)
   currentIndex.value = 0
   viewMode.value = 'list'
+  localStorage.setItem('viewMode', viewMode.value)
   // The v-if on the list container tears down and recreates all .observe DOM
   // nodes when switching views, so the intersection observer must be
   // re-pointed at the new elements after Vue has finished rendering.
@@ -405,6 +426,7 @@ function toggleViewMode() {
       observer = null
     }
     viewMode.value = 'article'
+    localStorage.setItem('viewMode', viewMode.value)
     currentIndex.value = 0
     markCurrentArticleRead()
   }