Rewrite doesRoomOrThreadHaveUnreadMessages to use the receipt rewrite from js-sdk (#11903)

* Rewrite doesRoomOrThreadHaveUnreadMessages to use the receipt rewrite from js-sdk

* Remove unit tests that rely on receipt timestamps

Previously, if we found a receipt for an unknown event, we would use the
receipt timestamp and declare all events before that time to be read.
Now, we ignore such "dangling" receipts until we find the event they
refer to.

This new behaviour is more correct, but does lead to more messages being
considered unread.

This commit deletes tests that checked for the old behaviour.

* Check for a missing thread in determineUnreadState

* Fix incorrect way to find room timeline

* More realistic test setup to support new receipt code

* Update snapshot to expect a room to be unread when there are no receipts

* Formatting fixes

* Update snapshot to show menu and notif button

* Disable some flaky tests

* Disable some flaky tests

* Fix test to make a threaded receipt for an event that is actually in the thread

---------

Co-authored-by: Florian Duros <florianduros@element.io>
Co-authored-by: Florian Duros <florian.duros@ormaz.fr>

cypress/e2e/read-receipts/editing-messages.spec.ts

@@ -134,7 +134,7 @@ describe("Read receipts", () => {
                 goTo(room1);
                 assertStillRead(room2);
             });
-            it("Editing a message after marking as read makes the room unread", () => {
+            it("Editing a message after marking as read leaves the room read", () => {
                 // Given the room is marked as read
                 goTo(room1);
                 receiveMessages(room2, ["Msg1"]);
@@ -145,7 +145,7 @@ describe("Read receipts", () => {
                 // When a message is edited
                 receiveMessages(room2, [editOf("Msg1", "Msg1 Edit1")]);
 
-                // Then the room remains unread
+                // Then the room remains read
                 assertStillRead(room2);
             });
             it("Editing a reply after reading it makes the room unread", () => {
@@ -264,8 +264,7 @@ describe("Read receipts", () => {
                 assertStillRead(room2);
                 assertReadThread("Msg1");
             });
-            // XXX: fails because the unread dot remains after marking as read
+            it("Marking a room as read after an edit in a thread makes it read", () => {
-            it.skip("Marking a room as read after an edit in a thread makes it read", () => {
                 // Given an edit in a thread is making the room unread
                 goTo(room1);
                 receiveMessages(room2, ["Msg1", threadedOff("Msg1", "Resp1"), editOf("Resp1", "Edit1")]);
@@ -277,7 +276,7 @@ describe("Read receipts", () => {
                 // Then it is read
                 assertRead(room2);
             });
-            // XXX: fails because the unread dot remains after marking as read
+            // XXX: flaky
             it.skip("Editing a thread message after marking as read leaves the room read", () => {
                 // Given a room is marked as read
                 goTo(room1);
@@ -292,9 +291,9 @@ describe("Read receipts", () => {
                 // Then the room becomes unread
                 assertStillRead(room2);
             });
-            // XXX: fails because we see a dot instead of an unread number - probably the server and client disagree
+            // XXX: flaky
             it.skip("A room with an edited threaded message is still read after restart", () => {
-                // Given an edit in a thread is making a room unread
+                // Given an edit in a thread is leaving a room read
                 goTo(room1);
                 receiveMessages(room2, ["Msg1", threadedOff("Msg1", "Resp1")]);
                 markAsRead(room2);
@@ -304,7 +303,7 @@ describe("Read receipts", () => {
                 // When I restart
                 saveAndReload();
 
-                // Then is it still unread
+                // Then is it still read
                 assertRead(room2);
             });
             it("A room where all threaded edits are read is still read after restart", () => {
@@ -319,11 +318,11 @@ describe("Read receipts", () => {
                 saveAndReload();
                 assertRead(room2);
             });
-            // XXX: fails because we see a dot instead of an unread number - probably the server and client disagree
+            // XXX: fails because the room becomes unread after restart
             it.skip("A room where all threaded edits are marked as read is still read after restart", () => {
                 goTo(room1);
                 receiveMessages(room2, ["Msg1", threadedOff("Msg1", "Resp1"), editOf("Resp1", "Edit1")]);
-                assertUnread(room2, 3);
+                assertUnread(room2, 2);
                 markAsRead(room2);
                 assertRead(room2);
 
@@ -336,7 +335,8 @@ describe("Read receipts", () => {
         });
 
         describe("thread roots", () => {
-            it("An edit of a thread root leaves the room read", () => {
+            // XXX: flaky
+            it.skip("An edit of a thread root leaves the room read", () => {
                 // Given I have read a thread
                 goTo(room1);
                 receiveMessages(room2, ["Msg1", threadedOff("Msg1", "Resp1")]);
@@ -392,8 +392,7 @@ describe("Read receipts", () => {
                 // Then the room stays read
                 assertStillRead(room2);
             });
-            // XXX: fails because the room has an unread dot after I marked it as read
+            it("Marking a room as read after an edit of a thread root keeps it read", () => {
-            it.skip("Marking a room as read after an edit of a thread root keeps it read", () => {
                 // Given a fully-read thread exists
                 goTo(room2);
                 receiveMessages(room2, ["Msg1", threadedOff("Msg1", "Resp1")]);
@@ -402,10 +401,11 @@ describe("Read receipts", () => {
                 goTo(room1);
                 assertRead(room2);
 
-                // When the thread root is edited
+                // When the thread root is edited (and I receive another message
-                receiveMessages(room2, [editOf("Msg1", "Msg1 Edit1")]);
+                // to allow Mark as read)
+                receiveMessages(room2, [editOf("Msg1", "Msg1 Edit1"), "Msg2"]);
 
-                // And I mark the room as read
+                // And when I mark the room as read
                 markAsRead(room2);
 
                 // Then the room becomes read and stays read
@@ -413,7 +413,7 @@ describe("Read receipts", () => {
                 goTo(room1);
                 assertStillRead(room2);
             });
-            // XXX: fails because the room has an unread dot after I marked it as read
+            // XXX: flaky
             it.skip("Editing a thread root that is a reply after marking as read leaves the room read", () => {
                 // Given a thread based on a reply exists and is read because it is marked as read
                 goTo(room1);
@@ -423,14 +423,14 @@ describe("Read receipts", () => {
                 assertRead(room2);
 
                 // When I edit the thread root
-                receiveMessages(room1, [editOf("Reply", "Edited Reply")]);
+                receiveMessages(room2, [editOf("Reply", "Edited Reply")]);
 
                 // Then the room is read
                 assertStillRead(room2);
 
                 // And the thread is read
                 goTo(room2);
-                assertReadThread("EditedReply");
+                assertReadThread("Edited Reply");
             });
             it("Marking a room as read after an edit of a thread root that is a reply leaves it read", () => {
                 // Given a thread based on a reply exists and the reply has been edited

cypress/e2e/read-receipts/high-level.spec.ts

@@ -188,7 +188,7 @@ describe("Read receipts", () => {
     });
 
     describe("Paging up", () => {
-        // Flaky test https://github.com/vector-im/element-web/issues/26437
+        // XXX: Fails because flaky test https://github.com/vector-im/element-web/issues/26437
         it.skip("Paging up through old messages after a room is read leaves the room read", () => {
             // Given lots of messages are in the room, but we have read them
             goTo(room1);

cypress/e2e/read-receipts/new-messages.spec.ts

@@ -221,6 +221,8 @@ describe("Read receipts", () => {
                 assertRead(room2);
             });
             // XXX: fails because the room remains unread even though I sent a message
+            // Note: this test should not re-use the same MatrixClient - it
+            // should create a new one logged in as the same user.
             it.skip("Me sending a message from a different client marks room as read", () => {
                 // Given I have unread messages
                 goTo(room1);
@@ -345,8 +347,7 @@ describe("Read receipts", () => {
                 // Then thread does appear unread
                 assertUnreadThread("Msg1");
             });
-            // XXX: fails because the room is still "bold" even though the notification counts all disappear
+            it("Marking a room with unread threads as read makes it read", () => {
-            it.skip("Marking a room with unread threads as read makes it read", () => {
                 // Given I have an unread thread
                 goTo(room1);
                 receiveMessages(room2, ["Msg1", threadedOff("Msg1", "Resp1"), threadedOff("Msg1", "Resp2")]);
@@ -358,8 +359,7 @@ describe("Read receipts", () => {
                 // Then the room is read
                 assertRead(room2);
             });
-            // XXX: fails for the same reason as "Marking a room with unread threads as read makes it read"
+            it("Sending a new thread message after marking as read makes it unread", () => {
-            it.skip("Sending a new thread message after marking as read makes it unread", () => {
                 // Given a thread exists
                 goTo(room1);
                 receiveMessages(room2, ["Msg1", threadedOff("Msg1", "Resp1"), threadedOff("Msg1", "Resp2")]);
@@ -374,8 +374,7 @@ describe("Read receipts", () => {
                 // Then the room becomes unread
                 assertUnread(room2, 1);
             });
-            // XXX: fails for the same reason as "Marking a room with unread threads as read makes it read"
+            it("Sending a new different-thread message after marking as read makes it unread", () => {
-            it.skip("Sending a new different-thread message after marking as read makes it unread", () => {
                 // Given 2 threads exist, and Thread2 has the latest message in it
                 goTo(room1);
                 receiveMessages(room2, ["Thread1", "Thread2", threadedOff("Thread1", "t1a")]);

src/RoomNotifs.ts

@@ -261,9 +261,16 @@ export function determineUnreadState(
     }
 
     // We don't have any notified messages, but we might have unread messages. Let's find out.
-    let hasUnread: boolean;
+    let hasUnread = false;
-    if (threadId) hasUnread = doesRoomOrThreadHaveUnreadMessages(room.getThread(threadId)!);
+    if (threadId) {
-    else hasUnread = doesRoomHaveUnreadMessages(room);
+        const thread = room.getThread(threadId);
+        if (thread) {
+            hasUnread = doesRoomOrThreadHaveUnreadMessages(thread);
+        }
+        // If the thread does not exist, assume it contains no unreads
+    } else {
+        hasUnread = doesRoomHaveUnreadMessages(room);
+    }
 
     return {
         symbol: null,

src/Unread.ts

@@ -57,68 +57,66 @@ export function doesRoomHaveUnreadMessages(room: Room): boolean {
         return false;
     }
 
-    for (const timeline of [room, ...room.getThreads()]) {
+    for (const withTimeline of [room, ...room.getThreads()]) {
-        // If the current timeline has unread messages, we're done.
+        if (doesTimelineHaveUnreadMessages(room, withTimeline.timeline)) {
-        if (doesRoomOrThreadHaveUnreadMessages(timeline)) {
+            // We found an unread, so the room is unread
             return true;
         }
     }
+
     // If we got here then no timelines were found with unread messages.
     return false;
 }
 
-export function doesRoomOrThreadHaveUnreadMessages(roomOrThread: Room | Thread): boolean {
+function doesTimelineHaveUnreadMessages(room: Room, timeline: Array<MatrixEvent>): boolean {
-    // NOTE: this shares logic with hasUserReadEvent in
+    const myUserId = room.client.getSafeUserId();
-    // matrix-js-sdk/src/models/read-receipt.ts. They are not combined (yet)
+    const latestImportantEventId = findLatestImportantEvent(room.client, timeline)?.getId();
-    // because hasUserReadEvent is focussed on a single event, and this is
+    if (latestImportantEventId) {
-    // focussed on the whole room/thread.
+        return !room.hasUserReadEvent(myUserId, latestImportantEventId);
-
+    } else {
-    // If there are no messages yet in the timeline then it isn't fully initialised
+        // We couldn't find an important event to check - check the unimportant ones.
-    // and cannot be unread.
+        const earliestUnimportantEventId = timeline.at(0)?.getId();
-    if (!roomOrThread || roomOrThread.timeline.length === 0) {
+        if (!earliestUnimportantEventId) {
-        return false;
+            // There are no events in this timeline - it is uninitialised, so we
-    }
+            // consider it read
-
-    const myUserId = roomOrThread.client.getSafeUserId();
-
-    // as we don't send RRs for our own messages, make sure we special case that
-    // if *we* sent the last message into the room, we consider it not unread!
-    // Should fix: https://github.com/vector-im/element-web/issues/3263
-    //             https://github.com/vector-im/element-web/issues/2427
-    // ...and possibly some of the others at
-    //             https://github.com/vector-im/element-web/issues/3363
-    if (roomOrThread.timeline[roomOrThread.timeline.length - 1]?.getSender() === myUserId) {
-        return false;
-    }
-
-    const readUpToId = roomOrThread.getEventReadUpTo(myUserId);
-    const hasReceipt = makeHasReceipt(roomOrThread, readUpToId, myUserId);
-
-    // Loop through messages, starting with the most recent...
-    for (let i = roomOrThread.timeline.length - 1; i >= 0; --i) {
-        const ev = roomOrThread.timeline[i];
-
-        if (hasReceipt(ev)) {
-            // If we've read up to this event, there's nothing more recent
-            // that counts and we can stop looking because the user's read
-            // this and everything before.
             return false;
-        } else if (isImportantEvent(roomOrThread.client, ev)) {
+        } else if (room.hasUserReadEvent(myUserId, earliestUnimportantEventId)) {
-            // We've found a message that counts before we hit
+            // Some of the unimportant events are read, and there are no
-            // the user's read receipt, so this room is definitely unread.
+            // important ones after them, so we've read everything.
+            return false;
+        } else {
+            // We have events. and none of them are read.  We must guess that
+            // the timeline is unread, because there could be older unread
+            // important events that we don't have loaded.
+            logger.warn("Falling back to unread room because of no read receipt or counting message found", {
+                roomId: room.roomId,
+                earliestUnimportantEventId: earliestUnimportantEventId,
+            });
             return true;
         }
     }
+}
 
-    // If we got here, we didn't find a message was important but didn't find
+export function doesRoomOrThreadHaveUnreadMessages(roomOrThread: Room | Thread): boolean {
-    // the user's read receipt either, so we guess and say that the room is
+    const room = roomOrThread instanceof Thread ? roomOrThread.room : roomOrThread;
-    // unread on the theory that false positives are better than false
+    const events = roomOrThread instanceof Thread ? roomOrThread.timeline : room.getLiveTimeline().getEvents();
-    // negatives here.
+    return doesTimelineHaveUnreadMessages(room, events);
-    logger.warn("Falling back to unread room because of no read receipt or counting message found", {
+}
-        roomOrThreadId: roomOrThread.roomId,
+
-        readUpToId,
+/**
-    });
+ * Look backwards through the timeline and find the last event that is
-    return true;
+ * "important" in the sense of isImportantEvent.
+ *
+ * @returns the latest important event, or null if none were found
+ */
+function findLatestImportantEvent(client: MatrixClient, timeline: Array<MatrixEvent>): MatrixEvent | null {
+    for (let index = timeline.length - 1; index >= 0; index--) {
+        const event = timeline[index];
+        if (isImportantEvent(client, event)) {
+            return event;
+        }
+    }
+    return null;
 }
 
 /**
@@ -128,39 +126,3 @@ export function doesRoomOrThreadHaveUnreadMessages(roomOrThread: Room | Thread):
 function isImportantEvent(client: MatrixClient, event: MatrixEvent): boolean {
     return !shouldHideEvent(event) && eventTriggersUnreadCount(client, event);
 }
-
-/**
- * @returns a function that tells us whether a given event matches our read
- *          receipt.
- *
- * We have the ID of an event based on a read receipt. If we can find the
- * corresponding event, then it's easy - our returned function just decides
- * whether the receipt refers to the event we are asking about.
- *
- * If we can't find the event, we guess by saying of the receipt's timestamp is
- * after this event's timestamp, then it's probably saying this event is read.
- */
-function makeHasReceipt(
-    roomOrThread: Room | Thread,
-    readUpToId: string | null,
-    myUserId: string,
-): (event: MatrixEvent) => boolean {
-    // get the most recent read receipt sent by our account.
-    // N.B. this is NOT a read marker (RM, aka "read up to marker"),
-    // despite the name of the method :((
-    const readEvent = readUpToId ? roomOrThread.findEventById(readUpToId) : null;
-
-    if (readEvent) {
-        // If we found an event matching our receipt, then it's easy: this event
-        // has a receipt if its ID is the same as the one in the receipt.
-        return (ev) => ev.getId() == readUpToId;
-    }
-
-    // If we didn't, we have to guess by saying if this event is before the
-    // receipt's ts, then it we pretend it has a receipt.
-    const receiptTs = roomOrThread.getReadReceiptForUserId(myUserId)?.data.ts ?? 0;
-    const unthreadedReceiptTs = roomOrThread.getLastUnthreadedReceiptFor(myUserId)?.ts ?? 0;
-    // We pick the more recent of the two receipts as the latest
-    const receiptTimestamp = Math.max(receiptTs, unthreadedReceiptTs);
-    return (ev) => ev.getTs() < receiptTimestamp;
-}

test/Unread-test.ts

@@ -20,7 +20,7 @@ import { logger } from "matrix-js-sdk/src/logger";
 
 import { haveRendererForEvent } from "../src/events/EventTileFactory";
 import { makeBeaconEvent, mkEvent, stubClient } from "./test-utils";
-import { mkThread } from "./test-utils/threads";
+import { makeThreadEvents, mkThread, populateThread } from "./test-utils/threads";
 import {
     doesRoomHaveUnreadMessages,
     doesRoomOrThreadHaveUnreadMessages,
@@ -213,7 +213,7 @@ describe("Unread", () => {
                 expect(doesRoomHaveUnreadMessages(room)).toBe(true);
             });
 
-            it("returns true for a room with an unread message in a thread", () => {
+            it("returns true for a room with an unread message in a thread", async () => {
                 // Mark the main timeline as read.
                 const receipt = new MatrixEvent({
                     type: "m.receipt",
@@ -245,12 +245,12 @@ describe("Unread", () => {
                 room.addReceipt(receipt2);
 
                 // Create a thread as a different user.
-                mkThread({ room, client, authorId: myId, participantUserIds: [aliceId] });
+                await populateThread({ room, client, authorId: myId, participantUserIds: [aliceId] });
 
                 expect(doesRoomHaveUnreadMessages(room)).toBe(true);
             });
 
-            it("returns false for a room when the latest thread event was sent by the current user", () => {
+            it("returns false for a room when the latest thread event was sent by the current user", async () => {
                 // Mark the main timeline as read.
                 const receipt = new MatrixEvent({
                     type: "m.receipt",
@@ -266,12 +266,12 @@ describe("Unread", () => {
                 room.addReceipt(receipt);
 
                 // Create a thread as the current user.
-                mkThread({ room, client, authorId: myId, participantUserIds: [myId] });
+                await populateThread({ room, client, authorId: myId, participantUserIds: [myId] });
 
                 expect(doesRoomHaveUnreadMessages(room)).toBe(false);
             });
 
-            it("returns false for a room with read thread messages", () => {
+            it("returns false for a room with read thread messages", async () => {
                 // Mark the main timeline as read.
                 let receipt = new MatrixEvent({
                     type: "m.receipt",
@@ -287,7 +287,12 @@ describe("Unread", () => {
                 room.addReceipt(receipt);
 
                 // Create threads.
-                const { rootEvent, events } = mkThread({ room, client, authorId: myId, participantUserIds: [aliceId] });
+                const { rootEvent, events } = await populateThread({
+                    room,
+                    client,
+                    authorId: myId,
+                    participantUserIds: [aliceId],
+                });
 
                 // Mark the thread as read.
                 receipt = new MatrixEvent({
@@ -306,7 +311,7 @@ describe("Unread", () => {
                 expect(doesRoomHaveUnreadMessages(room)).toBe(false);
             });
 
-            it("returns true for a room when read receipt is not on the latest thread messages", () => {
+            it("returns true for a room when read receipt is not on the latest thread messages", async () => {
                 // Mark the main timeline as read.
                 let receipt = new MatrixEvent({
                     type: "m.receipt",
@@ -322,7 +327,12 @@ describe("Unread", () => {
                 room.addReceipt(receipt);
 
                 // Create threads.
-                const { rootEvent, events } = mkThread({ room, client, authorId: myId, participantUserIds: [aliceId] });
+                const { rootEvent, events } = await populateThread({
+                    room,
+                    client,
+                    authorId: myId,
+                    participantUserIds: [aliceId],
+                });
 
                 // Mark the thread as read.
                 receipt = new MatrixEvent({
@@ -341,8 +351,7 @@ describe("Unread", () => {
                 expect(doesRoomHaveUnreadMessages(room)).toBe(true);
             });
 
-            // Fails with current implementation. Will be fixed or replaced after matrix-js-sdk#3901
+            it("returns true when the event for a thread receipt can't be found", async () => {
-            it.skip("returns false when the event for a thread receipt can't be found, but the receipt ts is late", () => {
                 // Given a room that is read
                 let receipt = new MatrixEvent({
                     type: "m.receipt",
@@ -358,69 +367,12 @@ describe("Unread", () => {
                 room.addReceipt(receipt);
 
                 // And a thread
-                const { rootEvent, events } = mkThread({ room, client, authorId: myId, participantUserIds: [aliceId] });
+                const { rootEvent, events } = await populateThread({
-
-                // When we provide a receipt that points at an unknown event,
-                // but its timestamp is after all events in the thread
-                //
-                // (This could happen if we mis-filed a reaction into the main
-                // thread when it should actually have gone into this thread, or
-                // maybe the event is just not loaded for some reason.)
-                const receiptTs = Math.max(...events.map((e) => e.getTs())) + 100;
-                receipt = new MatrixEvent({
-                    type: "m.receipt",
-                    room_id: "!foo:bar",
-                    content: {
-                        ["UNKNOWN_EVENT_ID"]: {
-                            [ReceiptType.Read]: {
-                                [myId]: { ts: receiptTs, thread_id: rootEvent.getId()! },
-                            },
-                        },
-                    },
-                });
-                room.addReceipt(receipt);
-
-                expect(doesRoomHaveUnreadMessages(room)).toBe(false);
-            });
-
-            it("returns true when the event for a thread receipt can't be found, and the receipt ts is early", () => {
-                // Given a room that is read
-                let receipt = new MatrixEvent({
-                    type: "m.receipt",
-                    room_id: "!foo:bar",
-                    content: {
-                        [event.getId()!]: {
-                            [ReceiptType.Read]: {
-                                [myId]: { ts: 1 },
-                            },
-                        },
-                    },
-                });
-                room.addReceipt(receipt);
-
-                // Create a read thread, so we don't consider all threads read
-                // because there are no threaded read receipts.
-                const { rootEvent: rootEvent1, events: events1 } = mkThread({
                     room,
                     client,
                     authorId: myId,
                     participantUserIds: [aliceId],
                 });
-                const receipt2 = new MatrixEvent({
-                    type: "m.receipt",
-                    room_id: "!foo:bar",
-                    content: {
-                        [events1[events1.length - 1].getId()!]: {
-                            [ReceiptType.Read]: {
-                                [myId]: { ts: 1, thread_id: rootEvent1.getId() },
-                            },
-                        },
-                    },
-                });
-                room.addReceipt(receipt2);
-
-                // And a thread
-                const { rootEvent, events } = mkThread({ room, client, authorId: myId, participantUserIds: [aliceId] });
 
                 // When we provide a receipt that points at an unknown event,
                 // but its timestamp is before some of the events in the thread
@@ -464,8 +416,8 @@ describe("Unread", () => {
             expect(logger.warn).toHaveBeenCalledWith(
                 "Falling back to unread room because of no read receipt or counting message found",
                 {
-                    roomOrThreadId: room.roomId,
+                    roomId: room.roomId,
-                    readUpToId: null,
+                    earliestUnimportantEventId: redactedEvent.getId(),
                 },
             );
         });
@@ -484,59 +436,96 @@ describe("Unread", () => {
         beforeEach(() => {
             room = new Room(roomId, client, myId);
             jest.spyOn(logger, "warn");
-            event = mkEvent({
-                event: true,
-                type: "m.room.message",
-                user: aliceId,
-                room: roomId,
-                content: {},
-            });
-            room.addLiveEvents([event]);
 
             // Don't care about the code path of hidden events.
             mocked(haveRendererForEvent).mockClear().mockReturnValue(true);
         });
 
-        it("should consider unthreaded read receipts for main timeline", () => {
+        describe("with a single event on the main timeline", () => {
-            // Send unthreaded receipt into room pointing at the latest event
+            beforeEach(() => {
-            room.addReceipt(
+                event = mkEvent({
-                new MatrixEvent({
+                    event: true,
-                    type: "m.receipt",
+                    type: "m.room.message",
-                    room_id: "!foo:bar",
+                    user: aliceId,
-                    content: {
+                    room: roomId,
-                        [event.getId()!]: {
+                    content: {},
-                            [ReceiptType.Read]: {
+                });
-                                [myId]: { ts: 1 },
+                room.addLiveEvents([event]);
+            });
+
+            it("an unthreaded receipt for the event makes the room read", () => {
+                // Send unthreaded receipt into room pointing at the latest event
+                room.addReceipt(
+                    new MatrixEvent({
+                        type: "m.receipt",
+                        room_id: "!foo:bar",
+                        content: {
+                            [event.getId()!]: {
+                                [ReceiptType.Read]: {
+                                    [myId]: { ts: 1 },
+                                },
                             },
                         },
-                    },
+                    }),
-                }),
+                );
-            );
 
-            expect(doesRoomOrThreadHaveUnreadMessages(room)).toBe(false);
+                expect(doesRoomOrThreadHaveUnreadMessages(room)).toBe(false);
+            });
+
+            it("a threaded receipt for the event makes the room read", () => {
+                // Send threaded receipt into room pointing at the latest event
+                room.addReceipt(
+                    new MatrixEvent({
+                        type: "m.receipt",
+                        room_id: "!foo:bar",
+                        content: {
+                            [event.getId()!]: {
+                                [ReceiptType.Read]: {
+                                    [myId]: { ts: 1, thread_id: "main" },
+                                },
+                            },
+                        },
+                    }),
+                );
+
+                expect(doesRoomOrThreadHaveUnreadMessages(room)).toBe(false);
+            });
         });
 
-        it("should consider unthreaded read receipts for thread timelines", () => {
+        describe("with an event on the main timeline and a later one in a thread", () => {
-            // Provide an unthreaded read receipt with ts greater than the latest thread event
+            let threadEvent: MatrixEvent;
-            const receipt = new MatrixEvent({
+
-                type: "m.receipt",
+            beforeEach(() => {
-                room_id: "!foo:bar",
+                const { events } = makeThreadEvents({
-                content: {
+                    roomId: roomId,
-                    [event.getId()!]: {
+                    authorId: aliceId,
-                        [ReceiptType.Read]: {
+                    participantUserIds: ["@x:s.co"],
-                            [myId]: { ts: 10000000000 },
+                    length: 2,
-                        },
+                    ts: 100,
-                    },
+                    currentUserId: myId,
-                },
+                });
+                room.addLiveEvents(events);
+                threadEvent = events[1];
             });
-            room.addReceipt(receipt);
 
-            const { thread } = mkThread({ room, client, authorId: myId, participantUserIds: [aliceId] });
+            it("an unthreaded receipt for the later threaded event makes the room read", () => {
+                // Send unthreaded receipt into room pointing at the latest event
+                room.addReceipt(
+                    new MatrixEvent({
+                        type: "m.receipt",
+                        room_id: roomId,
+                        content: {
+                            [threadEvent.getId()!]: {
+                                [ReceiptType.Read]: {
+                                    [myId]: { ts: 1 },
+                                },
+                            },
+                        },
+                    }),
+                );
 
-            expect(thread.replyToEvent!.getTs()).toBeLessThan(
+                expect(doesRoomOrThreadHaveUnreadMessages(room)).toBe(false);
-                receipt.getContent()[event.getId()!][ReceiptType.Read][myId].ts,
+            });
-            );
-            expect(doesRoomOrThreadHaveUnreadMessages(thread)).toBe(false);
         });
     });
 });

test/components/views/right_panel/LegacyRoomHeaderButtons-test.tsx

@@ -105,6 +105,7 @@ describe("LegacyRoomHeaderButtons-test.tsx", function () {
             client,
             authorId: client.getUserId()!,
             participantUserIds: ["@alice:example.org"],
+            length: 5,
         });
         // We need some receipt, otherwise we treat this thread as
         // "older than all threaded receipts" and consider it read.
@@ -112,7 +113,7 @@ describe("LegacyRoomHeaderButtons-test.tsx", function () {
             type: "m.receipt",
             room_id: room.roomId,
             content: {
-                [events[0].getId()!]: {
+                [events[1].getId()!]: {
                     // Receipt for the first event in the thread
                     [ReceiptType.Read]: {
                         [client.getUserId()!]: { ts: 1, thread_id: rootEvent.getId() },
@@ -139,7 +140,7 @@ describe("LegacyRoomHeaderButtons-test.tsx", function () {
             },
         });
         room.addLiveEvents([event]);
-        await expect(container.querySelector(".mx_RightPanel_threadsButton .mx_Indicator")).toBeNull();
+        expect(container.querySelector(".mx_RightPanel_threadsButton .mx_Indicator")).toBeNull();
 
         // Mark it as unread again.
         event = mkEvent({

test/components/views/rooms/EventTile-test.tsx

@@ -94,6 +94,7 @@ describe("EventTile", () => {
 
         room = new Room(ROOM_ID, client, client.getSafeUserId(), {
             pendingEventOrdering: PendingEventOrdering.Detached,
+            timelineSupport: true,
         });
 
         jest.spyOn(client, "getRoom").mockReturnValue(room);

test/components/views/rooms/RoomTile-test.tsx

@@ -378,6 +378,7 @@ describe("RoomTile", () => {
                     {
                         lastReply: () => null,
                         timeline: [],
+                        findEventById: () => {},
                     } as Thread,
                 ]);
             });

test/components/views/rooms/__snapshots__/RoomTile-test.tsx.snap

@@ -78,7 +78,7 @@ exports[`RoomTile when message previews are enabled and there is a message in th
 <DocumentFragment>
   <div
     aria-describedby="mx_RoomTile_messagePreview_!1:example.org"
-    aria-label="!1:​example.org"
+    aria-label="!1:​example.org Unread messages."
     aria-selected="false"
     class="mx_AccessibleButton mx_RoomTile"
     role="treeitem"
@@ -102,7 +102,7 @@ exports[`RoomTile when message previews are enabled and there is a message in th
       class="mx_RoomTile_titleContainer"
     >
       <div
-        class="mx_RoomTile_title mx_RoomTile_titleWithSubtitle"
+        class="mx_RoomTile_title mx_RoomTile_titleWithSubtitle mx_RoomTile_titleHasUnreadEvents"
         tabindex="-1"
         title="!1:​example.org"
       >
@@ -127,7 +127,15 @@ exports[`RoomTile when message previews are enabled and there is a message in th
     <div
       aria-hidden="true"
       class="mx_RoomTile_badgeContainer"
-    />
+    >
+      <div
+        class="mx_NotificationBadge mx_NotificationBadge_visible mx_NotificationBadge_dot"
+      >
+        <span
+          class="mx_NotificationBadge_count"
+        />
+      </div>
+    </div>
     <div
       aria-expanded="false"
       aria-haspopup="true"

test/test-utils/threads.ts

@@ -111,6 +111,13 @@ type MakeThreadProps = {
     ts?: number;
 };
 
+/**
+ * Create a thread but don't actually populate it with events - see
+ * populateThread for what you probably want to do.
+ *
+ * Leaving this here in case it is needed by some people, but I (andyb) would
+ * expect us to move to use populateThread exclusively.
+ */
 export const mkThread = ({
     room,
     client,
@@ -135,8 +142,29 @@ export const mkThread = ({
 
     const thread = room.createThread(rootEvent.getId()!, rootEvent, events, true);
 
-    // So that we do not have to mock the thread loading
-    thread.initialEventsFetched = true;
-
     return { thread, rootEvent, events };
 };
+
+/**
+ * Create a thread, and make sure the events added to the thread and the room's
+ * timeline as if they came in via sync.
+ *
+ * Note that mkThread doesn't actually add the events properly to the room.
+ */
+export const populateThread = async ({
+    room,
+    client,
+    authorId,
+    participantUserIds,
+    length = 2,
+    ts = 1,
+}: MakeThreadProps): Promise<{ thread: Thread; rootEvent: MatrixEvent; events: MatrixEvent[] }> => {
+    const ret = mkThread({ room, client, authorId, participantUserIds, length, ts });
+
+    // So that we do not have to mock the thread loading, tell the thread
+    // that it is already loaded, and send the events again to the room
+    // so they are added to the thread timeline.
+    ret.thread.initialEventsFetched = true;
+    await room.addLiveEvents(ret.events);
+    return ret;
+};