Add slash command to switch to a room's virtual room (#7839)

* Add slash command to switch to a room's virtual room

* Update to new interface

* Return null if no virtual user

* Throw newTranslateableError

* Types

* Disable tovirtual if virtual rooms not supported

src/VoipUserMapper.ts

@@ -42,13 +42,20 @@ export default class VoipUserMapper {
         return results[0].userid;
     }
 
-    public async getOrCreateVirtualRoomForRoom(roomId: string): Promise<string> {
+    private async getVirtualUserForRoom(roomId: string): Promise<string | null> {
         const userId = DMRoomMap.shared().getUserIdForRoomId(roomId);
         if (!userId) return null;
 
         const virtualUser = await this.userToVirtualUser(userId);
         if (!virtualUser) return null;
 
+        return virtualUser;
+    }
+
+    public async getOrCreateVirtualRoomForRoom(roomId: string): Promise<string | null> {
+        const virtualUser = await this.getVirtualUserForRoom(roomId);
+        if (!virtualUser) return null;
+
         const virtualRoomId = await ensureVirtualRoomExists(MatrixClientPeg.get(), virtualUser, roomId);
         MatrixClientPeg.get().setRoomAccountData(virtualRoomId, VIRTUAL_ROOM_EVENT_TYPE, {
             native_room: roomId,
@@ -59,6 +66,17 @@ export default class VoipUserMapper {
         return virtualRoomId;
     }
 
+    /**
+     * Gets the ID of the virtual room for a room, or null if the room has no
+     * virtual room
+     */
+    public async getVirtualRoomForRoom(roomId: string): Promise<Room | null> {
+        const virtualUser = await this.getVirtualUserForRoom(roomId);
+        if (!virtualUser) return null;
+
+        return findDMForUser(MatrixClientPeg.get(), virtualUser);
+    }
+
     public nativeRoomForVirtualRoom(roomId: string): string {
         const cachedNativeRoomId = this.virtualToNativeRoomIdCache.get(roomId);
         if (cachedNativeRoomId) {