fix(realtime): Allow connections for guest users

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

backend/src/realtime/realtime-note/realtime-note.ts

@@ -52,7 +52,7 @@ export class RealtimeNote extends (EventEmitter as TypedEventEmitterConstructor<
    */
   public addClient(client: WebsocketConnection): void {
     this.clients.add(client);
-    this.logger.debug(`User '${client.getUser().username}' connected`);
+    this.logger.debug(`User '${client.getUsername()}' connected`);
   }
 
   /**
@@ -63,7 +63,7 @@ export class RealtimeNote extends (EventEmitter as TypedEventEmitterConstructor<
   public removeClient(client: WebsocketConnection): void {
     this.clients.delete(client);
     this.logger.debug(
-      `User '${client.getUser().username}' disconnected. ${
+      `User '${client.getUsername()}' disconnected. ${
         this.clients.size
       } clients left.`,
     );

backend/src/realtime/realtime-note/test-utils/mock-connection.ts

@@ -18,5 +18,6 @@ export function mockConnection(synced: boolean): WebsocketConnection {
     isSynced: jest.fn(() => synced),
     send: jest.fn(),
     getUser: jest.fn(() => Mock.of<User>({ username: 'mockedUser' })),
+    getUsername: jest.fn(() => 'mocked user'),
   });
 }

backend/src/realtime/realtime-note/websocket-connection.spec.ts

@@ -192,4 +192,26 @@ describe('websocket connection', () => {
 
     expect(sut.getUser()).toBe(mockedUser);
   });
+
+  it('returns the correct username', () => {
+    const mockedUserWithUsername = Mock.of<User>({ username: 'MockUser' });
+
+    const sut = new WebsocketConnection(
+      mockedWebsocket,
+      mockedUserWithUsername,
+      mockedRealtimeNote,
+    );
+
+    expect(sut.getUsername()).toBe('MockUser');
+  });
+
+  it('returns a fallback if no username has been set', () => {
+    const sut = new WebsocketConnection(
+      mockedWebsocket,
+      mockedUser,
+      mockedRealtimeNote,
+    );
+
+    expect(sut.getUsername()).toBe('Guest');
+  });
 });

backend/src/realtime/realtime-note/websocket-connection.ts

@@ -30,7 +30,7 @@ export class WebsocketConnection {
    */
   constructor(
     websocket: WebSocket,
-    private user: User,
+    private user: User | null,
     realtimeNote: RealtimeNote,
   ) {
     const awareness = realtimeNote.getAwareness();
@@ -94,7 +94,11 @@ export class WebsocketConnection {
     return this.controlledAwarenessIds;
   }
 
-  public getUser(): User {
+  public getUser(): User | null {
     return this.user;
   }
+
+  public getUsername(): string {
+    return this.getUser()?.username ?? 'Guest';
+  }
 }