Order new search dialog results by recency (#8444)

* Order new search dialog results by recency

* Add getLastTs tests

* Add sort rooms tests

test/stores/room-list/algorithms/RecentAlgorithm-test.ts

@@ -0,0 +1,127 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { Room } from "matrix-js-sdk/src/models/room";
+
+import { stubClient, mkRoom, mkMessage } from "../../../test-utils";
+import { MatrixClientPeg } from "../../../../src/MatrixClientPeg";
+import "../../../../src/stores/room-list/RoomListStore";
+import { RecentAlgorithm } from "../../../../src/stores/room-list/algorithms/tag-sorting/RecentAlgorithm";
+import { EffectiveMembership } from "../../../../src/utils/membership";
+
+describe("RecentAlgorithm", () => {
+    let algorithm;
+    let cli;
+    beforeEach(() => {
+        stubClient();
+        cli = MatrixClientPeg.get();
+        algorithm = new RecentAlgorithm();
+    });
+
+    describe("getLastTs", () => {
+        it("returns the last ts", () => {
+            const room = new Room("room123", cli, "@john:matrix.org");
+
+            const event1 = mkMessage({
+                room: room.roomId,
+                msg: "Hello world!",
+                user: "@alice:matrix.org",
+                ts: 5,
+                event: true,
+            });
+            const event2 = mkMessage({
+                room: room.roomId,
+                msg: "Howdy!",
+                user: "@bob:matrix.org",
+                ts: 10,
+                event: true,
+            });
+
+            room.getMyMembership = () => "join";
+
+            room.addLiveEvents([event1]);
+            expect(algorithm.getLastTs(room, "@jane:matrix.org")).toBe(5);
+            expect(algorithm.getLastTs(room, "@john:matrix.org")).toBe(5);
+
+            room.addLiveEvents([event2]);
+
+            expect(algorithm.getLastTs(room, "@jane:matrix.org")).toBe(10);
+            expect(algorithm.getLastTs(room, "@john:matrix.org")).toBe(10);
+        });
+
+        it("returns a fake ts for rooms without a timeline", () => {
+            const room = mkRoom(cli, "!new:example.org");
+            room.timeline = undefined;
+            expect(algorithm.getLastTs(room, "@john:matrix.org")).toBe(Number.MAX_SAFE_INTEGER);
+        });
+
+        it("works when not a member", () => {
+            const room = mkRoom(cli, "!new:example.org");
+            room.getMyMembership.mockReturnValue(EffectiveMembership.Invite);
+            expect(algorithm.getLastTs(room, "@john:matrix.org")).toBe(Number.MAX_SAFE_INTEGER);
+        });
+    });
+
+    describe("sortRooms", () => {
+        it("orders rooms per last message ts", () => {
+            const room1 = new Room("room1", cli, "@bob:matrix.org");
+            const room2 = new Room("room2", cli, "@bob:matrix.org");
+
+            room1.getMyMembership = () => "join";
+            room2.getMyMembership = () => "join";
+
+            const evt = mkMessage({
+                room: room1.roomId,
+                msg: "Hello world!",
+                user: "@alice:matrix.org",
+                ts: 5,
+                event: true,
+            });
+            const evt2 = mkMessage({
+                room: room2.roomId,
+                msg: "Hello world!",
+                user: "@alice:matrix.org",
+                ts: 2,
+                event: true,
+            });
+
+            room1.addLiveEvents([evt]);
+            room2.addLiveEvents([evt2]);
+
+            expect(algorithm.sortRooms([room2, room1])).toEqual([room1, room2]);
+        });
+
+        it("orders rooms without messages first", () => {
+            const room1 = new Room("room1", cli, "@bob:matrix.org");
+            const room2 = new Room("room2", cli, "@bob:matrix.org");
+
+            room1.getMyMembership = () => "join";
+            room2.getMyMembership = () => "join";
+
+            const evt = mkMessage({
+                room: room1.roomId,
+                msg: "Hello world!",
+                user: "@alice:matrix.org",
+                ts: 5,
+                event: true,
+            });
+
+            room1.addLiveEvents([evt]);
+
+            expect(algorithm.sortRooms([room2, room1])).toEqual([room2, room1]);
+        });
+    });
+});