Wire local room logic (#9078)

* Wire local room logic

* Migrate to testling-lib; update test descriptions

test/utils/localRoom/isLocalRoom-test.ts

@@ -0,0 +1,52 @@
+/*
+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/matrix";
+
+import { LocalRoom, LOCAL_ROOM_ID_PREFIX } from "../../../src/models/LocalRoom";
+import { isLocalRoom } from "../../../src/utils/localRoom/isLocalRoom";
+import { createTestClient } from "../../test-utils";
+
+describe("isLocalRoom", () => {
+    let room: Room;
+    let localRoom: LocalRoom;
+
+    beforeEach(() => {
+        const client = createTestClient();
+        room = new Room("!room:example.com", client, client.getUserId());
+        localRoom = new LocalRoom(LOCAL_ROOM_ID_PREFIX + "test", client, client.getUserId());
+    });
+
+    it("should return false for null", () => {
+        expect(isLocalRoom(null)).toBe(false);
+    });
+
+    it("should return false for a Room", () => {
+        expect(isLocalRoom(room)).toBe(false);
+    });
+
+    it("should return false for a non-local room ID", () => {
+        expect(isLocalRoom(room.roomId)).toBe(false);
+    });
+
+    it("should return true for LocalRoom", () => {
+        expect(isLocalRoom(localRoom)).toBe(true);
+    });
+
+    it("should return true for local room ID", () => {
+        expect(isLocalRoom(LOCAL_ROOM_ID_PREFIX + "test")).toBe(true);
+    });
+});