Prepare utils for local rooms (#9084)

* Prepare utils for local rooms

* Split up direct-messages module

test/utils/dm/findDMForUser-test.ts

@@ -0,0 +1,72 @@
+/*
+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 } from "jest-mock";
+import { MatrixClient, Room } from "matrix-js-sdk/src/matrix";
+
+import { DirectoryMember, ThreepidMember } from "../../../src/utils/direct-messages";
+import { MatrixClientPeg } from "../../../src/MatrixClientPeg";
+import DMRoomMap from "../../../src/utils/DMRoomMap";
+import { createTestClient } from "../../test-utils";
+import { findDMRoom } from "../../../src/utils/dm/findDMRoom";
+import { findDMForUser } from "../../../src/utils/dm/findDMForUser";
+
+jest.mock("../../../src/utils/dm/findDMForUser", () => ({
+    findDMForUser: jest.fn(),
+}));
+
+describe("findDMRoom", () => {
+    const userId1 = "@user1:example.com";
+    const member1 = new DirectoryMember({ user_id: userId1 });
+    const member2 = new ThreepidMember("user2");
+    let mockClient: MatrixClient;
+    let room1: Room;
+    let dmRoomMap: DMRoomMap;
+
+    beforeEach(() => {
+        mockClient = createTestClient();
+        jest.spyOn(MatrixClientPeg, "get").mockReturnValue(mockClient);
+
+        room1 = new Room("!room1:example.com", mockClient, userId1);
+        room1.getMyMembership = () => "join";
+
+        dmRoomMap = {
+            getDMRoomForIdentifiers: jest.fn(),
+            getDMRoomsForUserId: jest.fn(),
+        } as unknown as DMRoomMap;
+        jest.spyOn(DMRoomMap, "shared").mockReturnValue(dmRoomMap);
+    });
+
+    it("should return the room for a single target with a room", () => {
+        mocked(findDMForUser).mockReturnValue(room1);
+        expect(findDMRoom(mockClient, [member1])).toBe(room1);
+    });
+
+    it("should return null for a single target without a room", () => {
+        mocked(findDMForUser).mockReturnValue(null);
+        expect(findDMRoom(mockClient, [member1])).toBeNull();
+    });
+
+    it("should return the room for 2 targets with a room", () => {
+        mocked(dmRoomMap.getDMRoomForIdentifiers).mockReturnValue(room1);
+        expect(findDMRoom(mockClient, [member1, member2])).toBe(room1);
+    });
+
+    it("should return null for 2 targets without a room", () => {
+        mocked(dmRoomMap.getDMRoomForIdentifiers).mockReturnValue(null);
+        expect(findDMRoom(mockClient, [member1, member2])).toBeNull();
+    });
+});