fix(threads): viewing a room no longer reads threads you don't follow (#314)

A passive read (just looking at the room) sent a threaded receipt for
every unread thread you don't follow, so the Threads panel's Unread
filter and Mark all read only ever worked for followed threads.
Decision (2026-10-19): leave them unread until opened, but stop
counting unfollowed threads toward the room's unread dot
(getUnreadInfo subtracts them like muted threads; a mention makes a
thread followed, so highlights are never hidden). isThreadFollowed
moves to utils/room. Adds a Playwright regression.

Fixes #314

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

e2e/local-homeserver.spec.ts

@@ -265,6 +265,46 @@ test.describe('local homeserver regression', () => {
     await expect.poll(threadUnread).toBe(false);
   });
 
+  test("a thread I don't follow stays unread while I view the room (#314)", async ({ page }) => {
+    const room = await createRoom(alice, 'Unfollowed Thread Room', { invite: [bob.userId] });
+    await joinRoom(bob, room);
+    const inThread = (root: string) => ({
+      'm.relates_to': {
+        rel_type: 'm.thread',
+        event_id: root,
+        is_falling_back: true,
+        'm.in_reply_to': { event_id: root },
+      },
+    });
+    const root = await sendText(bob, room, "bob's thread root");
+    await loginUI(page, alice);
+    await openRoom(page, room);
+    await sendText(bob, room, 'reply in bob thread', inThread(root));
+    await sendText(bob, room, 'newer main message 314');
+    await expect(page.getByText('newer main message 314')).toBeVisible();
+    const threadUnread = async () => {
+      const filter = {
+        room: {
+          rooms: [room],
+          timeline: { limit: 1, unread_thread_notifications: true, not_types: [uniq('x.')] },
+        },
+      };
+      const sync = await api<{
+        rooms: {
+          join: Record<string, { unread_thread_notifications?: Record<string, unknown> }>;
+        };
+      }>(
+        'GET',
+        `/_matrix/client/v3/sync?timeout=0&filter=${enc(JSON.stringify(filter))}`,
+        alice.token,
+      );
+      return root in (sync.rooms.join[room]?.unread_thread_notifications ?? {});
+    };
+    await page.waitForTimeout(2000); // let any receipt the room view would send go out
+    // Viewing the room used to read every thread you don't follow (#314).
+    expect(await threadUnread()).toBe(true);
+  });
+
   test('timeline image opens the gallery lightbox (#219) @webkit', async ({ page }) => {
     const room = await createRoom(alice, 'Lightbox Room');
     const png = Buffer.from(

src/app/utils/notifications.test.ts

@@ -169,7 +169,7 @@ test('private receipt flag uses ReadPrivate', async () => {
 // follows unread; an explicit mark-as-read still clears everything.
 const sender = (userId: string) => ({ getSender: () => userId });
 
-test('passive: a thread I replied in stays unread; main receipt is scoped to main', async () => {
+test('passive: threads stay unread, followed or not; main receipt is scoped to main (#314)', async () => {
   const mine = thread('$mine', evt('$r1'), { hasCurrentUserParticipated: true });
   const other = thread('$other', evt('$r2'));
   const { mx, calls } = setup({
@@ -181,10 +181,9 @@ test('passive: a thread I replied in stays unread; main receipt is scoped to mai
   await markAsRead(mx, '!r:server', false, { passive: true });
   assert.deepEqual(
     calls.map((c) => [c.eventId, c.unthreaded]),
-    [
-      ['b', false], // main-scoped: unthreaded would also read $mine's reply
-      ['$r2', false],
-    ],
+    // main-scoped (unthreaded would read the threads' replies), and no thread
+    // receipts: [Gitea #314] unfollowed threads used to be read silently.
+    [['b', false]],
   );
 });
 
@@ -203,7 +202,7 @@ test('passive: threads I started or was mentioned in stay unread', async () => {
   assert.equal(calls.length, 0);
 });
 
-test('passive: no followed thread unread → main receipt stays unthreaded', async () => {
+test('passive: an unfollowed unread thread is left unread too (#314)', async () => {
   const other = thread('$other', evt('$r2'), { rootEvent: sender('@bob:server') });
   const { mx, calls } = setup({
     timeline: [evt('a'), evt('b')],
@@ -214,10 +213,16 @@ test('passive: no followed thread unread → main receipt stays unthreaded', asy
   await markAsRead(mx, '!r:server', false, { passive: true });
   assert.deepEqual(
     calls.map((c) => [c.eventId, c.unthreaded]),
-    [
-      ['b', true],
-      ['$r2', false],
-    ],
+    [['b', false]],
+  );
+});
+
+test('passive: no thread unread → main receipt stays unthreaded', async () => {
+  const { mx, calls } = setup({ timeline: [evt('a'), evt('b')], readUpTo: 'a', threads: [] });
+  await markAsRead(mx, '!r:server', false, { passive: true });
+  assert.deepEqual(
+    calls.map((c) => [c.eventId, c.unthreaded]),
+    [['b', true]],
   );
 });
 
@@ -249,9 +254,10 @@ test('passive: the thread open in the panel is left to the panel', async () => {
     threadUnread: { $open: 1, $other: 1 },
   });
   await markAsRead(mx, '!r:server', false, { passive: true, openThreadId: '$open' });
+  // The open thread is left to the panel, and [#314] the other one stays unread.
   assert.deepEqual(
     calls.map((c) => c.eventId),
-    ['$r2'],
+    [],
   );
 });
 

src/app/utils/notifications.ts

@@ -1,27 +1,19 @@
-import { MatrixClient, NotificationCountType, ReceiptType, Room, Thread } from 'matrix-js-sdk';
+import { MatrixClient, NotificationCountType, ReceiptType, Thread } from 'matrix-js-sdk';
 import { getSettings } from '../state/settings';
 import { readMarkedUnread, setMarkedUnread } from '../state/room/markedUnread';
+import { isThreadFollowed } from './room';
 
-/**
- * [Gitea #217] Threads the user is following: they started it, replied in it,
- * or were mentioned in it. `hasCurrentUserParticipated` comes from the server's
- * thread bundle and lags a reply we just sent, so our own loaded events count too.
- */
-export function isThreadFollowed(room: Room, thread: Thread, userId: string | null): boolean {
-  if (thread.hasCurrentUserParticipated) return true;
-  if (userId && thread.rootEvent?.getSender() === userId) return true;
-  if (userId && thread.timeline?.some((e) => e.getSender() === userId)) return true;
-  return (
-    (room.getThreadUnreadNotificationCount(thread.id, NotificationCountType.Highlight) ?? 0) > 0
-  );
-}
+// isThreadFollowed lives in utils/room (getUnreadInfo needs it too).
+export { isThreadFollowed };
 
 export type MarkAsReadOptions = {
   /**
    * [Gitea #217] The read comes from simply looking at the room (timeline at
-   * the bottom and focused), not an explicit "mark as read". Threads the user
-   * follows stay unread until their panel is opened, like Slack and Discord;
-   * the rest are cleared so they don't keep the room dot lit forever.
+   * the bottom and focused), not an explicit "mark as read". Threads stay
+   * unread until opened (or "Mark all read"), like Slack and Discord.
+   * [Gitea #314] That includes threads you don't follow; those no longer
+   * count toward the room's unread dot (see getUnreadInfo), so leaving them
+   * unread doesn't keep the room lit.
    */
   passive?: boolean;
   /**
@@ -66,7 +58,9 @@ export async function markAsRead(
   const threads = room.getThreads();
   const threadUnread = (thread: Thread) =>
     room.getThreadUnreadNotificationCount(thread.id, NotificationCountType.Total) ?? 0;
-  const keepThread = (thread: Thread) => passive && isThreadFollowed(room, thread, mx.getUserId());
+  // [Gitea #314] A passive read leaves every thread's state alone (it used to
+  // silently read every thread you don't follow).
+  const keepThread = (_thread: Thread) => passive;
   // [Gitea #217] An unthreaded receipt also reads every thread reply older than
   // it, so a passive read while a followed thread is unread must stay scoped
   // to the main timeline or the next main message would clear that thread.

src/app/utils/room.test.ts

@@ -928,3 +928,42 @@ test('getAllVersionsRoomCreator returns empty set when no create event', () => {
 test('EventTimeline.FORWARDS constant is available', () => {
   assert.equal(typeof EventTimeline.FORWARDS, 'string');
 });
+
+test('getUnreadInfo: unfollowed threads do not light the room; followed and mentioned do (#314)', () => {
+  const threads = [
+    { id: '$followed', hasCurrentUserParticipated: true },
+    { id: '$other' },
+    { id: '$mention' },
+  ];
+  const counts: Record<string, { total: number; highlight: number }> = {
+    $followed: { total: 2, highlight: 0 },
+    $other: { total: 3, highlight: 0 },
+    $mention: { total: 1, highlight: 1 },
+  };
+  const room = {
+    roomId: '!r:x',
+    // Server room totals include thread counts: 2 + 3 + 1 thread, 0 main.
+    getUnreadNotificationCount: (type: NotificationCountType) =>
+      type === NotificationCountType.Total ? 6 : 1,
+    getThreads: () => threads,
+    getThreadUnreadNotificationCount: (id: string, type: NotificationCountType) =>
+      type === NotificationCountType.Total ? counts[id].total : counts[id].highlight,
+    getEventReadUpTo: () => null,
+    getLiveTimeline: () => ({ getEvents: () => [] }),
+  } as unknown as Room;
+  const me = { getUserId: () => '@me:x' } as unknown as MatrixClient;
+  assert.deepEqual(getUnreadInfo(room, undefined, me), { roomId: '!r:x', highlight: 1, total: 3 });
+  // Only an unfollowed thread is unread: the room isn't lit.
+  counts.$followed.total = 0;
+  counts.$mention = { total: 0, highlight: 0 };
+  const onlyOther = {
+    ...room,
+    getUnreadNotificationCount: (type: NotificationCountType) =>
+      type === NotificationCountType.Total ? 3 : 0,
+  } as unknown as Room;
+  assert.deepEqual(getUnreadInfo(onlyOther, undefined, me), {
+    roomId: '!r:x',
+    highlight: 0,
+    total: 0,
+  });
+});

src/app/utils/room.ts

@@ -18,6 +18,7 @@ import {
   NotificationCountType,
   RelationType,
   Room,
+  Thread,
   RoomMember,
   TimelineEvents,
   IRoomTimelineData,
@@ -418,6 +419,20 @@ export const roomHaveUnread = (mx: MatrixClient, room: Room) => {
   return true;
 };
 
+/**
+ * [Gitea #217] Threads the user is following: they started it, replied in it,
+ * or were mentioned in it. `hasCurrentUserParticipated` comes from the server's
+ * thread bundle and lags a reply we just sent, so our own loaded events count too.
+ */
+export function isThreadFollowed(room: Room, thread: Thread, userId: string | null): boolean {
+  if (thread.hasCurrentUserParticipated) return true;
+  if (userId && thread.rootEvent?.getSender() === userId) return true;
+  if (userId && thread.timeline?.some((e) => e.getSender() === userId)) return true;
+  return (
+    (room.getThreadUnreadNotificationCount(thread.id, NotificationCountType.Highlight) ?? 0) > 0
+  );
+}
+
 export const getUnreadInfo = (
   room: Room,
   mutedThreads?: Set<string>,
@@ -439,6 +454,18 @@ export const getUnreadInfo = (
     if (highlight < 0) highlight = 0;
   }
 
+  // [Gitea #314] Threads you don't follow stay unread in the Threads panel
+  // (viewing the room no longer reads them) but don't light the room's dot.
+  // A mention makes a thread followed, so highlights are never subtracted.
+  if (mx) {
+    room.getThreads().forEach((thread) => {
+      if (mutedThreads?.has(thread.id)) return;
+      if (isThreadFollowed(room, thread, mx.getUserId())) return;
+      total -= room.getThreadUnreadNotificationCount(thread.id, NotificationCountType.Total) ?? 0;
+    });
+    if (total < 0) total = 0;
+  }
+
   const resolvedTotal = highlight > total ? highlight : total;
 
   // Suppress a spurious Total when the room isn't really unread. Two safe cases,