Room list: remove usage of algorithms of old room list store (#33975)

* feat:add missing methods to rls V3

* feat: use rls v3 methods instead of old alrgorithms

* feat: move stabel function to own utils

* feat: use this new moved functions

* test: cleaner test

apps/web/src/components/views/dialogs/AddExistingToSpaceDialog.tsx

@@ -27,7 +27,7 @@ import DMRoomMap from "../../../utils/DMRoomMap";
 import { calculateRoomVia } from "../../../utils/permalinks/Permalinks";
 import StyledCheckbox from "../elements/StyledCheckbox";
 import MatrixClientContext from "../../../contexts/MatrixClientContext";
-import { sortRooms } from "../../../stores/room-list/algorithms/tag-sorting/RecentAlgorithm";
+import { sortRoomsByRecency } from "../../../utils/room/sortRoomsByRecency";
 import ProgressBar from "../elements/ProgressBar";
 import DecoratedRoomAvatar from "../avatars/DecoratedRoomAvatar";
 import QueryMatcher from "../../../autocomplete/QueryMatcher";
@@ -172,7 +172,7 @@ export const AddExistingToSpace: React.FC<IAddExistingToSpaceProps> = ({
         }
 
         const joinRule = space.getJoinRule();
-        return sortRooms(rooms).reduce<[spaces: Room[], rooms: Room[], dms: Room[]]>(
+        return sortRoomsByRecency(rooms, cli.getSafeUserId()).reduce<[spaces: Room[], rooms: Room[], dms: Room[]]>(
             (arr, room) => {
                 if (room.isSpaceRoom()) {
                     if (room !== space && !existingSubspacesSet.has(room)) {
@@ -190,7 +190,7 @@ export const AddExistingToSpace: React.FC<IAddExistingToSpaceProps> = ({
             },
             [[], [], []],
         );
-    }, [visibleRooms, space, lcQuery, existingRoomsSet, existingSubspacesSet]);
+    }, [visibleRooms, space, lcQuery, existingRoomsSet, existingSubspacesSet, cli]);
 
     const addRooms = async (): Promise<void> => {
         setError(false);

apps/web/src/components/views/dialogs/ForwardDialog.tsx

@@ -38,7 +38,7 @@ import DecoratedRoomAvatar from "../avatars/DecoratedRoomAvatar";
 import { StaticNotificationState } from "../../../stores/notifications/StaticNotificationState";
 import NotificationBadge from "../rooms/NotificationBadge";
 import { type RoomPermalinkCreator } from "../../../utils/permalinks/Permalinks";
-import { sortRooms } from "../../../stores/room-list/algorithms/tag-sorting/RecentAlgorithm";
+import { sortRoomsByRecency } from "../../../utils/room/sortRoomsByRecency";
 import QueryMatcher from "../../../autocomplete/QueryMatcher";
 import TruncatedList from "../elements/TruncatedList";
 import { Action } from "../../../dispatcher/actions";
@@ -284,10 +284,11 @@ const ForwardDialog: React.FC<IProps> = ({ matrixClient: cli, event, permalinkCr
 
     let rooms = useMemo(
         () =>
-            sortRooms(
+            sortRoomsByRecency(
                 cli
                     .getVisibleRooms(msc3946DynamicRoomPredecessors)
                     .filter((room) => room.getMyMembership() === KnownMembership.Join && !room.isSpaceRoom()),
+                cli.getSafeUserId(),
             ),
         [cli, msc3946DynamicRoomPredecessors],
     );

apps/web/src/components/views/dialogs/spotlight/SpotlightDialog.tsx

@@ -70,7 +70,7 @@ import SettingsStore from "../../../../settings/SettingsStore";
 import { BreadcrumbsStore } from "../../../../stores/BreadcrumbsStore";
 import { type RoomNotificationState } from "../../../../stores/notifications/RoomNotificationState";
 import { RoomNotificationStateStore } from "../../../../stores/notifications/RoomNotificationStateStore";
-import { RecentAlgorithm } from "../../../../stores/room-list/algorithms/tag-sorting/RecentAlgorithm";
+import { compareRoomsByRecency } from "../../../../utils/room/sortRoomsByRecency";
 import { SdkContextClass } from "../../../../contexts/SDKContext";
 import { getMetaSpaceName, MetaSpace } from "../../../../stores/spaces";
 import SpaceStore from "../../../../stores/spaces/SpaceStore";
@@ -252,8 +252,6 @@ const toMemberResult = (member: Member | RoomMember, alreadyFiltered: boolean):
     query: [member.userId.toLowerCase(), member.name.toLowerCase()].filter(Boolean),
 });
 
-const recentAlgorithm = new RecentAlgorithm();
-
 export const useWebSearchMetrics = (numResults: number, queryLength: number, viaSpotlight: boolean): void => {
     useEffect(() => {
         if (!queryLength) return;
@@ -498,7 +496,6 @@ const SpotlightDialog: React.FC<IProps> = ({ initialText = "", initialFilter = n
         }
 
         // Sort results by most recent activity
-
         const myUserId = cli.getSafeUserId();
         for (const resultArray of Object.values(results)) {
             resultArray.sort((a: Result, b: Result) => {
@@ -507,7 +504,7 @@ const SpotlightDialog: React.FC<IProps> = ({ initialText = "", initialFilter = n
                     if (!isRoomResult(b)) return -1;
                     if (!isRoomResult(a)) return -1;
 
-                    return recentAlgorithm.getLastTs(b.room, myUserId) - recentAlgorithm.getLastTs(a.room, myUserId);
+                    return compareRoomsByRecency(a.room, b.room, myUserId);
                 } else if (isMemberResult(a) || isMemberResult(b)) {
                     // Member results should appear just after room results
                     if (!isMemberResult(b)) return -1;
@@ -520,7 +517,7 @@ const SpotlightDialog: React.FC<IProps> = ({ initialText = "", initialFilter = n
         }
 
         return results;
-    }, [trimmedQuery, filter, cli, possibleResults, userDirectorySearchResults, memberComparator]);
+    }, [cli, trimmedQuery, filter, possibleResults, userDirectorySearchResults, memberComparator]);
 
     const numResults = sum(Object.values(results).map((it) => it.length));
     useWebSearchMetrics(numResults, query.length, true);

apps/web/src/utils/room/sortRoomsByRecency.ts

@@ -0,0 +1,45 @@
+/*
+Copyright 2026 Element Creations Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE files in the repository root for full details.
+*/
+
+import type { Room } from "matrix-js-sdk/src/matrix";
+import { getLastTimestamp } from "../../stores/room-list-v3/skip-list/sorters/utils/getLastTimestamp";
+
+/**
+ * Sort an arbitrary list of rooms by recency (most recent activity first).
+ *
+ * Unlike the main room list sorting, this is a pure recency sort: muted and
+ * low-priority rooms are NOT moved to the bottom. The provided array is not
+ * mutated; a sorted copy is returned. The given list is sorted as-is and is
+ * not filtered by the active space.
+ * @param rooms The rooms to sort.
+ * @param userId The mxId of the current user.
+ */
+export function sortRoomsByRecency(rooms: Room[], userId: string): Room[] {
+    const cache = new Map<string, number>();
+    const ts = (room: Room): number => {
+        let value = cache.get(room.roomId);
+        if (value === undefined) {
+            value = getLastTimestamp(room, userId);
+            cache.set(room.roomId, value);
+        }
+        return value;
+    };
+    return [...rooms].sort((a, b) => ts(b) - ts(a));
+}
+
+/**
+ * Compare two rooms by recency, most recent activity first.
+ *
+ * Intended for sorting mixed result sets where rooms need to be ordered
+ * relative to each other (e.g. spotlight search results).
+ * @param roomA The first room.
+ * @param roomB The second room.
+ * @param userId The mxId of the current user.
+ */
+export function compareRoomsByRecency(roomA: Room, roomB: Room, userId: string): number {
+    return getLastTimestamp(roomB, userId) - getLastTimestamp(roomA, userId);
+}

apps/web/test/unit-tests/utils/room/sortRoomsByRecency-test.ts

@@ -0,0 +1,57 @@
+/*
+Copyright 2026 Element Creations Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE files in the repository root for full details.
+*/
+
+import { type Room } from "matrix-js-sdk/src/matrix";
+
+import { createTestClient } from "../../../test-utils";
+import { getMockedRooms } from "../../stores/room-list-v3/skip-list/getMockedRooms";
+import { DefaultTagID } from "../../../../src/stores/room-list-v3/skip-list/tag";
+import { compareRoomsByRecency, sortRoomsByRecency } from "../../../../src/utils/room/sortRoomsByRecency";
+
+describe("sortRoomsByRecency", () => {
+    let userId: string;
+    let rooms: Room[];
+
+    beforeEach(() => {
+        const client = createTestClient();
+        userId = client.getSafeUserId();
+        rooms = getMockedRooms(client);
+    });
+
+    describe("sortRoomsByRecency", () => {
+        it("sorts an arbitrary list by recency without mutating the input", () => {
+            const input = [rooms[0], rooms[5], rooms[2]];
+            const inputCopy = [...input];
+
+            const sorted = sortRoomsByRecency(input, userId);
+
+            // ts: room5 (6) > room2 (3) > room0 (1)
+            expect(sorted).toEqual([rooms[5], rooms[2], rooms[0]]);
+            // The input array is not mutated.
+            expect(input).toEqual(inputCopy);
+        });
+
+        it("does not move muted or low-priority rooms (pure recency)", () => {
+            const recent = rooms[99]; // highest ts
+            recent.tags = { [DefaultTagID.LowPriority]: { order: 0 } };
+
+            const sorted = sortRoomsByRecency([rooms[0], rooms[50], recent], userId);
+
+            // A pure recency sort keeps the most recent room first even though it is
+            // low priority (the full RecencySorter would sink it).
+            expect(sorted[0]).toBe(recent);
+        });
+    });
+
+    describe("compareRoomsByRecency", () => {
+        it("orders the more recent room first", () => {
+            // rooms[10] (ts 11) is more recent than rooms[3] (ts 4)
+            expect(compareRoomsByRecency(rooms[10], rooms[3], userId)).toBeLessThan(0);
+            expect(compareRoomsByRecency(rooms[3], rooms[10], userId)).toBeGreaterThan(0);
+        });
+    });
+});