Room list: fix *Chat moved* toast appearing when room list is loaded (#34305)

* Fix Chat moved toast appearing when room list is loaded

* Update e2e tests

apps/web/playwright/e2e/left-panel/room-list-panel/room-list-unread-toast.spec.ts

@@ -181,15 +181,6 @@ test.describe("Room list unread activity toast", () => {
             // Wait until the collapsed Chats header has been pushed offscreen (all favourites synced).
             await expect(chatsHeader).not.toBeInViewport();
 
-            // Tagging rooms into the Favourites section raises a transient "Chat moved" toast, which
-            // shares the single toast slot with — and takes precedence over — the unread-activity toast
-            // (see RoomListView). Dismiss it via its close button so the unread toast can surface; by now
-            // all favourites have synced, so it will not re-appear.
-            const chatMovedToast = page.getByText("Chat moved");
-            await expect(chatMovedToast).toBeVisible();
-            await page.getByRole("button", { name: "Close" }).click();
-            await expect(chatMovedToast).not.toBeVisible();
-
             // The collapsed Chats header is offscreen, but its hidden notification raises the toast.
             await expect(getToast(page)).toBeVisible();
 

apps/web/src/stores/room-list-v3/RoomListStoreV3.ts

@@ -272,8 +272,16 @@ export class RoomListStoreV3Class extends AsyncStoreWithClient<EmptyObject> {
             }
 
             case "MatrixActions.Room.tags": {
+                // Re-sort on any tag change, but don't emit ROOM_TAGGED_EVENT here: the js-sdk
+                // re-emits RoomEvent.Tags for every m.tag on every sync, which would show a spurious
+                // "chat moved" toast on load. It is emitted from tagRoom.success below instead.
                 const room = payload.room;
                 this.addRoomAndEmit(room);
+                break;
+            }
+
+            case "RoomListActions.tagRoom.success": {
+                // Tag change initiated by the local user, so surface the "chat moved" toast.
                 this.emit(ROOM_TAGGED_EVENT);
                 break;
             }

apps/web/test/unit-tests/stores/room-list-v3/RoomListStoreV3-test.ts

@@ -13,6 +13,7 @@ import type { MatrixClient } from "matrix-js-sdk/src/matrix";
 import type { RoomNotificationState } from "../../../../src/stores/notifications/RoomNotificationState";
 import {
     LISTS_UPDATE_EVENT,
+    ROOM_TAGGED_EVENT,
     SECTION_CREATED_EVENT,
     RoomListStoreV3Class,
     type Section,
@@ -346,6 +347,19 @@ describe("RoomListStoreV3", () => {
             expect(fn).toHaveBeenCalled();
         });
 
+        it("emits ROOM_TAGGED_EVENT on a local user tag action", async () => {
+            const { store, dispatcher } = await getRoomListStore();
+            const fn = jest.fn();
+            store.on(ROOM_TAGGED_EVENT, fn);
+            dispatcher.dispatch(
+                {
+                    action: "RoomListActions.tagRoom.success",
+                },
+                true,
+            );
+            expect(fn).toHaveBeenCalled();
+        });
+
         it("Room is re-inserted on decryption", async () => {
             const { store, rooms, client, dispatcher } = await getRoomListStore();
             jest.spyOn(client, "getRoom").mockImplementation(() => rooms[10]);