Test inserting edit events into the thread timeline "on demand"

spec/test-utils/test-utils.ts

@@ -370,6 +370,37 @@ export function mkReaction(
     );
 }
 
+export function mkEdit(
+    target: MatrixEvent,
+    client: MatrixClient,
+    userId: string,
+    roomId: string,
+    msg?: string,
+    ts?: number,
+) {
+    msg = msg ?? `Edit of ${target.getId()}`;
+    return mkEvent(
+        {
+            event: true,
+            type: EventType.RoomMessage,
+            user: userId,
+            room: roomId,
+            content: {
+                "body": `* ${msg}`,
+                "m.new_content": {
+                    body: msg,
+                },
+                "m.relates_to": {
+                    rel_type: RelationType.Replace,
+                    event_id: target.getId()!,
+                },
+            },
+            ts,
+        },
+        client,
+    );
+}
+
 /**
  * A mock implementation of webstorage
  */

spec/unit/event-timeline-set.spec.ts

@@ -24,13 +24,10 @@ import {
     MatrixClient,
     MatrixEvent,
     MatrixEventEvent,
-    RelationType,
     Room,
-    RoomEvent,
 } from "../../src";
-import { FeatureSupport, Thread } from "../../src/models/thread";
+import { Thread } from "../../src/models/thread";
 import { ReEmitter } from "../../src/ReEmitter";
-import { eventMapperFor } from "../../src/event-mapper";
 
 describe("EventTimelineSet", () => {
     const roomId = "!foo:bar";
@@ -206,88 +203,6 @@ describe("EventTimelineSet", () => {
             expect(liveTimeline.getEvents().length).toStrictEqual(0);
         });
 
-        it("should allow edits to be added to thread timeline", async () => {
-            jest.spyOn(client, "supportsThreads").mockReturnValue(true);
-            jest.spyOn(client, "getEventMapper").mockReturnValue(eventMapperFor(client, {}));
-            Thread.hasServerSideSupport = FeatureSupport.Stable;
-
-            const sender = "@alice:matrix.org";
-
-            const root = utils.mkEvent({
-                event: true,
-                content: {
-                    body: "Thread root",
-                },
-                type: EventType.RoomMessage,
-                sender,
-            });
-            room.addLiveEvents([root]);
-
-            const threadReply = utils.mkEvent({
-                event: true,
-                content: {
-                    "body": "Thread reply",
-                    "m.relates_to": {
-                        event_id: root.getId()!,
-                        rel_type: RelationType.Thread,
-                    },
-                },
-                type: EventType.RoomMessage,
-                sender,
-            });
-
-            root.setUnsigned({
-                "m.relations": {
-                    [RelationType.Thread]: {
-                        count: 1,
-                        latest_event: {
-                            content: threadReply.getContent(),
-                            origin_server_ts: 5,
-                            room_id: room.roomId,
-                            sender,
-                            type: EventType.RoomMessage,
-                            event_id: threadReply.getId()!,
-                            user_id: sender,
-                            age: 1,
-                        },
-                        current_user_participated: true,
-                    },
-                },
-            });
-
-            const editToThreadReply = utils.mkEvent({
-                event: true,
-                content: {
-                    "body": " * edit",
-                    "m.new_content": {
-                        "body": "edit",
-                        "msgtype": "m.text",
-                        "org.matrix.msc1767.text": "edit",
-                    },
-                    "m.relates_to": {
-                        event_id: threadReply.getId()!,
-                        rel_type: RelationType.Replace,
-                    },
-                },
-                type: EventType.RoomMessage,
-                sender,
-            });
-
-            jest.spyOn(client, "paginateEventTimeline").mockImplementation(async () => {
-                thread.timelineSet.getLiveTimeline().addEvent(threadReply, { toStartOfTimeline: true });
-                return true;
-            });
-            jest.spyOn(client, "relations").mockResolvedValue({
-                events: [],
-            });
-
-            const thread = room.createThread(root.getId()!, root, [threadReply, editToThreadReply], false);
-            thread.once(RoomEvent.TimelineReset, () => {
-                const lastEvent = thread.timeline.at(-1)!;
-                expect(lastEvent.getContent().body).toBe(" * edit");
-            });
-        });
-
         describe("non-room timeline", () => {
             it("Adds event to timeline", () => {
                 const nonRoomEventTimelineSet = new EventTimelineSet(

spec/unit/models/thread.spec.ts

@@ -17,12 +17,12 @@ limitations under the License.
 import { mocked } from "jest-mock";
 
 import { MatrixClient, PendingEventOrdering } from "../../../src/client";
-import { Room } from "../../../src/models/room";
+import { Room, RoomEvent } from "../../../src/models/room";
 import { Thread, THREAD_RELATION_TYPE, ThreadEvent, FeatureSupport } from "../../../src/models/thread";
-import { mkThread } from "../../test-utils/thread";
+import { makeThreadEvent, mkThread } from "../../test-utils/thread";
 import { TestClient } from "../../TestClient";
-import { emitPromise, mkMessage, mkReaction, mock } from "../../test-utils/test-utils";
-import { Direction, EventStatus, MatrixEvent } from "../../../src";
+import { emitPromise, mkEdit, mkMessage, mkReaction, mock } from "../../test-utils/test-utils";
+import { Direction, EventStatus, EventType, MatrixEvent } from "../../../src";
 import { ReceiptType } from "../../../src/@types/read_receipts";
 import { getMockClientWithEventEmitter, mockClientMethodsUser } from "../../test-utils/client";
 import { ReEmitter } from "../../../src/ReEmitter";
@@ -474,4 +474,134 @@ describe("Thread", () => {
             return client;
         }
     });
+
+    describe("Editing events", () => {
+        describe("Given server support for threads", () => {
+            let previousThreadHasServerSideSupport: FeatureSupport;
+
+            beforeAll(() => {
+                previousThreadHasServerSideSupport = Thread.hasServerSideSupport;
+                Thread.hasServerSideSupport = FeatureSupport.Stable;
+            });
+
+            afterAll(() => {
+                Thread.hasServerSideSupport = previousThreadHasServerSideSupport;
+            });
+
+            it("Adds edits from sync to the thread timeline and applies them", async () => {
+                // Given a thread
+                const client = createClient();
+                const user = "@alice:matrix.org";
+                const room = "!room:z";
+                const thread = await createThread(client, user, room);
+
+                // When a message and an edit are added to the thread
+                const messageToEdit = createThreadMessage(thread.id, user, room, "Thread reply");
+                const editEvent = mkEdit(messageToEdit, client, user, room, "edit");
+                await thread.addEvent(messageToEdit, false);
+                await thread.addEvent(editEvent, false);
+
+                // Then both events end up in the timeline
+                const lastEvent = thread.timeline.at(-1)!;
+                const secondLastEvent = thread.timeline.at(-2)!;
+                expect(lastEvent).toBe(editEvent);
+                expect(secondLastEvent).toBe(messageToEdit);
+
+                // And the first message has been edited
+                expect(secondLastEvent.getContent().body).toEqual("edit");
+            });
+
+            it("Adds edits fetched on demand to the thread timeline and applies them", async () => {
+                // Given we don't support recursive relations
+                const client = createClient(new Map([[Feature.RelationsRecursion, ServerSupport.Unsupported]]));
+                // And we have a thread
+                const user = "@alice:matrix.org";
+                const room = "!room:z";
+                const thread = await createThread(client, user, room);
+
+                // When a message is added to the thread, and an edit to it is provided on demand
+                const messageToEdit = createThreadMessage(thread.id, user, room, "Thread reply");
+                // (fetchEditsWhereNeeded only applies to encrypted messages for some reason)
+                messageToEdit.event.type = EventType.RoomMessageEncrypted;
+                const editEvent = mkEdit(messageToEdit, client, user, room, "edit");
+                mocked(client.relations).mockImplementation(async (_roomId, eventId) => {
+                    if (eventId === messageToEdit.getId()) {
+                        return { events: [editEvent] };
+                    } else {
+                        return { events: [] };
+                    }
+                });
+                await thread.addEvent(messageToEdit, false);
+
+                // THIS IS THE CORRECT BEHAVIOUR
+                // Then both events end up in the timeline
+                //const lastEvent = thread.timeline.at(-1)!;
+                //const secondLastEvent = thread.timeline.at(-2)!;
+                //expect(lastEvent).toBe(editEvent);
+                //expect(secondLastEvent).toBe(messageToEdit);
+
+                //// And the first message has been edited
+                //expect(secondLastEvent.getContent().body).toEqual("edit");
+
+                // TODO: For now, we incorrecly DON'T add the event to the timeline
+                const lastEvent = thread.timeline.at(-1)!;
+                expect(lastEvent).toBe(messageToEdit);
+                // But the original is edited, as expected
+                expect(lastEvent.getContent().body).toEqual("edit");
+            });
+        });
+    });
 });
+
+/**
+ * Create a message event that lives in a thread
+ */
+function createThreadMessage(threadId: string, user: string, room: string, msg: string): MatrixEvent {
+    return makeThreadEvent({
+        event: true,
+        user,
+        room,
+        msg,
+        rootEventId: threadId,
+        replyToEventId: threadId,
+    });
+}
+
+/**
+ * Create a thread and wait for it to be properly initialised (so you can safely
+ * add events to it and expect them to appear in the timeline.
+ */
+async function createThread(client: MatrixClient, user: string, roomId: string): Promise<Thread> {
+    const root = mkMessage({ event: true, user, room: roomId, msg: "Thread root" });
+    const room = new Room(roomId, client, "@roomcreator:x");
+
+    // Ensure the root is in the room timeline
+    root.setThreadId(root.getId());
+    room.addLiveEvents([root]);
+
+    // Create the thread and wait for it to be initialised
+    const thread = room.createThread(root.getId()!, root, [], false);
+    await new Promise<void>((res) => thread.once(RoomEvent.TimelineReset, () => res()));
+
+    return thread;
+}
+
+/**
+ * Create a MatrixClient that supports threads and has all the methods used when
+ * creating a thread that call out to HTTP endpoints mocked out.
+ */
+function createClient(canSupport = new Map()): MatrixClient {
+    const client = mock(MatrixClient, "MatrixClient");
+    client.reEmitter = mock(ReEmitter, "ReEmitter");
+    client.canSupport = canSupport;
+
+    jest.spyOn(client, "supportsThreads").mockReturnValue(true);
+    jest.spyOn(client, "getEventMapper").mockReturnValue(eventMapperFor(client, {}));
+
+    // Mock methods that call out to HTTP endpoints
+    jest.spyOn(client, "paginateEventTimeline").mockResolvedValue(true);
+    jest.spyOn(client, "relations").mockResolvedValue({ events: [] });
+    jest.spyOn(client, "fetchRoomEvent").mockResolvedValue({});
+
+    return client;
+}

src/models/thread.ts

@@ -499,7 +499,8 @@ export class Thread extends ReadReceipt<EmittedEvents, EventHandlerMap> {
                 events
                     .filter((e) => e.isEncrypted())
                     .map((event: MatrixEvent) => {
-                        if (event.isRelation()) return; // skip - relations don't get edits
+                        // The only type of relation that gets edits is a thread message.
+                        if (event.getThread() === undefined && event.isRelation()) return;
                         return this.client
                             .relations(this.roomId, event.getId()!, RelationType.Replace, event.getType(), {
                                 limit: 1,