Don't switch to the home page needlessly after leaving a room (#9477)

Currently, if you leave a room that you're not currently viewing, you'll get sent back to the home page for no reason. This creates needless friction when trying to leave multiple rooms belonging to a space from the room list.

In addition to that fix, this improves the behavior when leaving a subspace, by making it take you to the parent space rather than all the way back home.

src/utils/leave-behaviour.ts

@@ -128,17 +128,32 @@ export async function leaveRoomBehaviour(roomId: string, retry = true, spinner =
         return;
     }
 
-    if (!isMetaSpace(SpaceStore.instance.activeSpace) &&
-        SpaceStore.instance.activeSpace !== roomId &&
-        SdkContextClass.instance.roomViewStore.getRoomId() === roomId
-    ) {
-        dis.dispatch<ViewRoomPayload>({
-            action: Action.ViewRoom,
-            room_id: SpaceStore.instance.activeSpace,
-            metricsTrigger: undefined, // other
-        });
-    } else {
-        dis.dispatch<ViewHomePagePayload>({ action: Action.ViewHomePage });
+    if (SdkContextClass.instance.roomViewStore.getRoomId() === roomId) {
+        // We were viewing the room that was just left. In order to avoid
+        // accidentally viewing the next room in the list and clearing its
+        // notifications, switch to a neutral ground such as the home page or
+        // space landing page.
+        if (isMetaSpace(SpaceStore.instance.activeSpace)) {
+            dis.dispatch<ViewHomePagePayload>({ action: Action.ViewHomePage });
+        } else if (SpaceStore.instance.activeSpace === roomId) {
+            // View the parent space, if there is one
+            const parent = SpaceStore.instance.getCanonicalParent(roomId);
+            if (parent !== null) {
+                dis.dispatch<ViewRoomPayload>({
+                    action: Action.ViewRoom,
+                    room_id: parent.roomId,
+                    metricsTrigger: undefined, // other
+                });
+            } else {
+                dis.dispatch<ViewHomePagePayload>({ action: Action.ViewHomePage });
+            }
+        } else {
+            dis.dispatch<ViewRoomPayload>({
+                action: Action.ViewRoom,
+                room_id: SpaceStore.instance.activeSpace,
+                metricsTrigger: undefined, // other
+            });
+        }
     }
 }
 

test/utils/leave-behaviour-test.ts

@@ -0,0 +1,124 @@
+/*
+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 { mocked, Mocked } from "jest-mock";
+import { MatrixClient } from "matrix-js-sdk/src/client";
+import { Room } from "matrix-js-sdk/src/models/room";
+
+import { MatrixClientPeg } from "../../src/MatrixClientPeg";
+import { mkRoom, resetAsyncStoreWithClient, setupAsyncStoreWithClient, stubClient } from "../test-utils";
+import defaultDispatcher from "../../src/dispatcher/dispatcher";
+import { ViewRoomPayload } from "../../src/dispatcher/payloads/ViewRoomPayload";
+import { Action } from "../../src/dispatcher/actions";
+import { leaveRoomBehaviour } from "../../src/utils/leave-behaviour";
+import { SdkContextClass } from "../../src/contexts/SDKContext";
+import DMRoomMap from "../../src/utils/DMRoomMap";
+import SpaceStore from "../../src/stores/spaces/SpaceStore";
+import { MetaSpace } from "../../src/stores/spaces";
+import { ActionPayload } from "../../src/dispatcher/payloads";
+
+describe("leaveRoomBehaviour", () => {
+    SdkContextClass.instance.constructEagerStores(); // Initialize RoomViewStore
+
+    let client: Mocked<MatrixClient>;
+    let room: Mocked<Room>;
+    let space: Mocked<Room>;
+
+    beforeEach(async () => {
+        stubClient();
+        client = mocked(MatrixClientPeg.get());
+        DMRoomMap.makeShared();
+
+        room = mkRoom(client, "!1:example.org");
+        space = mkRoom(client, "!2:example.org");
+        space.isSpaceRoom.mockReturnValue(true);
+        client.getRoom.mockImplementation(roomId => {
+            switch (roomId) {
+                case room.roomId: return room;
+                case space.roomId: return space;
+                default: return null;
+            }
+        });
+
+        await setupAsyncStoreWithClient(SpaceStore.instance, client);
+    });
+
+    afterEach(async () => {
+        SpaceStore.instance.setActiveSpace(MetaSpace.Home);
+        await resetAsyncStoreWithClient(SpaceStore.instance);
+        jest.restoreAllMocks();
+    });
+
+    const viewRoom = (room: Room) => defaultDispatcher.dispatch<ViewRoomPayload>({
+        action: Action.ViewRoom,
+        room_id: room.roomId,
+        metricsTrigger: undefined,
+    }, true);
+
+    const expectDispatch = async <T extends ActionPayload>(payload: T) => {
+        const dispatcherSpy = jest.fn();
+        const dispatcherRef = defaultDispatcher.register(dispatcherSpy);
+        await new Promise<void>(resolve => setImmediate(resolve)); // Flush the dispatcher
+        expect(dispatcherSpy).toHaveBeenCalledWith(payload);
+        defaultDispatcher.unregister(dispatcherRef);
+    };
+
+    it("returns to the home page after leaving a room outside of a space that was being viewed", async () => {
+        viewRoom(room);
+
+        await leaveRoomBehaviour(room.roomId);
+        await expectDispatch({ action: Action.ViewHomePage });
+    });
+
+    it("returns to the parent space after leaving a room inside of a space that was being viewed", async () => {
+        jest.spyOn(SpaceStore.instance, "getCanonicalParent").mockImplementation(
+            roomId => roomId === room.roomId ? space : null,
+        );
+        viewRoom(room);
+        SpaceStore.instance.setActiveSpace(space.roomId, false);
+
+        await leaveRoomBehaviour(room.roomId);
+        await expectDispatch({
+            action: Action.ViewRoom,
+            room_id: space.roomId,
+            metricsTrigger: undefined,
+        });
+    });
+
+    it("returns to the home page after leaving a top-level space that was being viewed", async () => {
+        viewRoom(space);
+        SpaceStore.instance.setActiveSpace(space.roomId, false);
+
+        await leaveRoomBehaviour(space.roomId);
+        await expectDispatch({ action: Action.ViewHomePage });
+    });
+
+    it("returns to the parent space after leaving a subspace that was being viewed", async () => {
+        room.isSpaceRoom.mockReturnValue(true);
+        jest.spyOn(SpaceStore.instance, "getCanonicalParent").mockImplementation(
+            roomId => roomId === room.roomId ? space : null,
+        );
+        viewRoom(room);
+        SpaceStore.instance.setActiveSpace(room.roomId, false);
+
+        await leaveRoomBehaviour(room.roomId);
+        await expectDispatch({
+            action: Action.ViewRoom,
+            room_id: space.roomId,
+            metricsTrigger: undefined,
+        });
+    });
+});