feat(realtime): add disconnect reason

The frontend now doesn't try to reconnect, when the disconnection happened because of a lack of permissions

Signed-off-by: Philip Molares <philip.molares@udo.edu>

backend/src/realtime/websocket/backend-websocket-adapter.spec.ts

@@ -3,9 +3,14 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-import { ConnectionState, Message, MessageType } from '@hedgedoc/commons';
+import {
+  ConnectionState,
+  DisconnectReason,
+  Message,
+  MessageType,
+} from '@hedgedoc/commons';
 import { Mock } from 'ts-mockery';
-import WebSocket, { MessageEvent } from 'ws';
+import WebSocket, { CloseEvent, MessageEvent } from 'ws';
 
 import { BackendWebsocketAdapter } from './backend-websocket-adapter';
 
@@ -29,17 +34,26 @@ describe('backend websocket adapter', () => {
   });
 
   it('can bind and unbind the close event', () => {
-    const handler = jest.fn();
+    const handler = jest.fn((reason?: DisconnectReason) => console.log(reason));
+
+    let modifiedHandler: (event: CloseEvent) => void = jest.fn();
+    jest
+      .spyOn(mockedSocket, 'addEventListener')
+      .mockImplementation((event, handler_) => {
+        modifiedHandler = handler_;
+      });
+
     const unbind = sut.bindOnCloseEvent(handler);
-    expect(mockedSocket.addEventListener).toHaveBeenCalledWith(
-      'close',
-      handler,
+
+    modifiedHandler(
+      Mock.of<CloseEvent>({ code: DisconnectReason.USER_NOT_PERMITTED }),
     );
+    expect(handler).toHaveBeenCalledTimes(1);
+    expect(handler).toHaveBeenCalledWith(DisconnectReason.USER_NOT_PERMITTED);
+
     unbind();
-    expect(mockedSocket.removeEventListener).toHaveBeenCalledWith(
-      'close',
-      handler,
-    );
+
+    expect(mockedSocket.removeEventListener).toHaveBeenCalled();
   });
 
   it('can bind and unbind the connect event', () => {

backend/src/realtime/websocket/backend-websocket-adapter.ts

@@ -3,9 +3,14 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-import { ConnectionState, Message, MessageType } from '@hedgedoc/commons';
+import {
+  ConnectionState,
+  DisconnectReason,
+  Message,
+  MessageType,
+} from '@hedgedoc/commons';
 import type { TransportAdapter } from '@hedgedoc/commons';
-import WebSocket, { MessageEvent } from 'ws';
+import WebSocket, { CloseEvent, MessageEvent } from 'ws';
 
 /**
  * Implements a transport adapter that communicates using a nodejs socket.
@@ -13,10 +18,13 @@ import WebSocket, { MessageEvent } from 'ws';
 export class BackendWebsocketAdapter implements TransportAdapter {
   constructor(private socket: WebSocket) {}
 
-  bindOnCloseEvent(handler: () => void): () => void {
-    this.socket.addEventListener('close', handler);
+  bindOnCloseEvent(handler: (reason?: DisconnectReason) => void): () => void {
+    function callback(event: CloseEvent): void {
+      handler(event.code);
+    }
+    this.socket.addEventListener('close', callback);
     return () => {
-      this.socket.removeEventListener('close', handler);
+      this.socket.removeEventListener('close', callback);
     };
   }
 

backend/src/realtime/websocket/websocket.gateway.ts

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 import {
+  DisconnectReason,
   MessageTransporter,
   NotePermissions,
   userCanEdit,
@@ -66,13 +67,11 @@ export class WebsocketGateway implements OnGatewayConnection {
         note,
       );
       if (notePermission < NotePermission.READ) {
-        //TODO: [mrdrogdrog] inform client about reason of disconnect.
-        // (https://github.com/hedgedoc/hedgedoc/issues/5034)
         this.logger.log(
           `Access denied to note '${note.id}' for user '${username}'`,
           'handleConnection',
         );
-        clientSocket.close();
+        clientSocket.close(DisconnectReason.USER_NOT_PERMITTED);
         return;
       }
 

commons/src/message-transporters/disconnect_reason.ts

@@ -0,0 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+export enum DisconnectReason {
+  USER_NOT_PERMITTED = 4000
+}

commons/src/message-transporters/index.ts

@@ -9,3 +9,4 @@ export * from './message-transporter.js'
 export * from './realtime-user.js'
 export * from './transport-adapter.js'
 export * from './mocked-backend-transport-adapter.js'
+export * from './disconnect_reason.js'

commons/src/message-transporters/message-transporter.ts

@@ -1,17 +1,25 @@
 /*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-import { Message, MessagePayloads, MessageType } from './message.js'
+import {
+  ConnectionStateEvent,
+  Message,
+  MessagePayloads,
+  MessageType
+} from './message.js'
 import { TransportAdapter } from './transport-adapter.js'
 import { EventEmitter2, Listener } from 'eventemitter2'
+import { DisconnectReason } from './disconnect_reason.js'
 
-export type MessageEvents = MessageType | 'connected' | 'disconnected' | 'ready'
+export type AllEvents = MessageType | ConnectionStateEvent
 
 type MessageEventPayloadMap = {
-  [E in MessageEvents]: E extends keyof MessagePayloads
+  [E in AllEvents]: E extends keyof MessagePayloads
     ? (message: Message<E>) => void
+    : E extends ConnectionStateEvent.DISCONNECTED
+    ? (reason?: DisconnectReason) => void
     : () => void
 }
 
@@ -157,14 +165,14 @@ export class MessageTransporter extends EventEmitter2<MessageEventPayloadMap> {
     }
   }
 
-  private bindWebsocketEvents(websocket: TransportAdapter) {
-    this.destroyOnErrorEventHandler = websocket.bindOnErrorEvent(
+  private bindWebsocketEvents(transportAdapter: TransportAdapter) {
+    this.destroyOnErrorEventHandler = transportAdapter.bindOnErrorEvent(
       this.onDisconnecting.bind(this)
     )
-    this.destroyOnCloseEventHandler = websocket.bindOnCloseEvent(
+    this.destroyOnCloseEventHandler = transportAdapter.bindOnCloseEvent(
       this.onDisconnecting.bind(this)
     )
-    this.destroyOnMessageEventHandler = websocket.bindOnMessageEvent(
+    this.destroyOnMessageEventHandler = transportAdapter.bindOnMessageEvent(
       this.receiveMessage.bind(this)
     )
   }
@@ -172,10 +180,10 @@ export class MessageTransporter extends EventEmitter2<MessageEventPayloadMap> {
   protected onConnected(): void {
     this.destroyOnConnectedEventHandler?.()
     this.destroyOnConnectedEventHandler = undefined
-    this.emit('connected')
+    this.emit(ConnectionStateEvent.CONNECTED)
   }
 
-  protected onDisconnecting(): void {
+  protected onDisconnecting(reason?: DisconnectReason): void {
     if (this.transportAdapter === undefined) {
       return
     }
@@ -184,7 +192,7 @@ export class MessageTransporter extends EventEmitter2<MessageEventPayloadMap> {
     this.thisSideReady = false
     this.otherSideReady = false
     this.transportAdapter = undefined
-    this.emit('disconnected')
+    this.emit(ConnectionStateEvent.DISCONNECTED, reason)
   }
 
   /**

commons/src/message-transporters/message.ts

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
@@ -22,6 +22,12 @@ export enum MessageType {
   READY_ANSWER = 'READY_ANSWER'
 }
 
+export enum ConnectionStateEvent {
+  READY = 'ready',
+  CONNECTED = 'connected',
+  DISCONNECTED = 'disconnected'
+}
+
 export interface MessagePayloads {
   [MessageType.NOTE_CONTENT_STATE_REQUEST]: number[]
   [MessageType.NOTE_CONTENT_UPDATE]: number[]

commons/src/message-transporters/transport-adapter.ts

@@ -5,6 +5,7 @@
  */
 import { ConnectionState } from './message-transporter.js'
 import { Message, MessageType } from './message.js'
+import { DisconnectReason } from './disconnect_reason.js'
 
 /**
  * Defines methods that must be implemented to send and receive messages using an {@link AdapterMessageTransporter}.
@@ -18,7 +19,7 @@ export interface TransportAdapter {
 
   bindOnErrorEvent(handler: () => void): () => void
 
-  bindOnCloseEvent(handler: () => void): () => void
+  bindOnCloseEvent(handler: (reason?: DisconnectReason) => void): () => void
 
   disconnect(): void
 

frontend/src/components/editor-page/editor-pane/hooks/yjs/frontend-websocket-adapter.spec.ts

@@ -5,7 +5,7 @@
  */
 import { FrontendWebsocketAdapter } from './frontend-websocket-adapter'
 import type { Message } from '@hedgedoc/commons'
-import { ConnectionState, MessageType } from '@hedgedoc/commons'
+import { ConnectionState, DisconnectReason, MessageType } from '@hedgedoc/commons'
 import { Mock } from 'ts-mockery'
 
 describe('frontend websocket', () => {
@@ -34,11 +34,22 @@ describe('frontend websocket', () => {
 
   it('can bind and unbind the close event', () => {
     mockSocket()
-    const handler = jest.fn()
+    const handler = jest.fn((reason?: DisconnectReason) => console.log(reason))
+
+    let modifiedHandler: (event: CloseEvent) => void = jest.fn()
+    jest.spyOn(mockedSocket, 'addEventListener').mockImplementation((event, handler_) => {
+      modifiedHandler = handler_
+    })
+
     const unbind = adapter.bindOnCloseEvent(handler)
-    expect(addEventListenerSpy).toHaveBeenCalledWith('close', handler)
+
+    modifiedHandler(Mock.of<CloseEvent>({ code: DisconnectReason.USER_NOT_PERMITTED }))
+    expect(handler).toHaveBeenCalledTimes(1)
+    expect(handler).toHaveBeenCalledWith(DisconnectReason.USER_NOT_PERMITTED)
+
     unbind()
-    expect(removeEventListenerSpy).toHaveBeenCalledWith('close', handler)
+
+    expect(removeEventListenerSpy).toHaveBeenCalled()
   })
 
   it('can bind and unbind the connect event', () => {

frontend/src/components/editor-page/editor-pane/hooks/yjs/frontend-websocket-adapter.ts

@@ -3,9 +3,8 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-import type { TransportAdapter } from '@hedgedoc/commons'
+import type { DisconnectReason, Message, MessageType, TransportAdapter } from '@hedgedoc/commons'
 import { ConnectionState } from '@hedgedoc/commons'
-import type { Message, MessageType } from '@hedgedoc/commons'
 
 /**
  * Implements a transport adapter that communicates using a browser websocket.
@@ -13,10 +12,11 @@ import type { Message, MessageType } from '@hedgedoc/commons'
 export class FrontendWebsocketAdapter implements TransportAdapter {
   constructor(private socket: WebSocket) {}
 
-  bindOnCloseEvent(handler: () => void): () => void {
-    this.socket.addEventListener('close', handler)
+  bindOnCloseEvent(handler: (reason?: DisconnectReason) => void): () => void {
+    const callback = (event: CloseEvent): void => handler(event.code)
+    this.socket.addEventListener('close', callback)
     return () => {
-      this.socket.removeEventListener('close', handler)
+      this.socket.removeEventListener('close', callback)
     }
   }
 

frontend/src/components/editor-page/editor-pane/hooks/yjs/use-realtime-connection.ts

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
@@ -10,7 +10,7 @@ import { Logger } from '../../../../../utils/logger'
 import { isMockMode } from '../../../../../utils/test-modes'
 import { FrontendWebsocketAdapter } from './frontend-websocket-adapter'
 import { useWebsocketUrl } from './use-websocket-url'
-import { MessageTransporter, MockedBackendTransportAdapter } from '@hedgedoc/commons'
+import { DisconnectReason, MessageTransporter, MockedBackendTransportAdapter } from '@hedgedoc/commons'
 import type { Listener } from 'eventemitter2'
 import { useCallback, useEffect, useMemo, useRef } from 'react'
 
@@ -28,6 +28,7 @@ export const useRealtimeConnection = (): MessageTransporter => {
   const messageTransporter = useMemo(() => new MessageTransporter(), [])
 
   const reconnectCount = useRef(0)
+  const disconnectReason = useRef<DisconnectReason | undefined>(undefined)
   const establishWebsocketConnection = useCallback(() => {
     if (isMockMode) {
       logger.debug('Creating Loopback connection...')
@@ -57,7 +58,7 @@ export const useRealtimeConnection = (): MessageTransporter => {
   const isConnected = useApplicationState((state) => state.realtimeStatus.isConnected)
 
   useEffect(() => {
-    if (isConnected || reconnectCount.current > 0) {
+    if (isConnected || reconnectCount.current > 0 || disconnectReason.current === DisconnectReason.USER_NOT_PERMITTED) {
       return
     }
     establishWebsocketConnection()
@@ -86,9 +87,16 @@ export const useRealtimeConnection = (): MessageTransporter => {
 
   useEffect(() => {
     const connectedListener = messageTransporter.doAsSoonAsReady(() => setRealtimeConnectionState(true))
-    const disconnectedListener = messageTransporter.on('disconnected', () => setRealtimeConnectionState(false), {
+    const disconnectedListener = messageTransporter.on(
+      'disconnected',
+      (reason?: DisconnectReason) => {
+        disconnectReason.current = reason
+        setRealtimeConnectionState(false)
+      },
+      {
         objectify: true
-    }) as Listener
+      }
+    ) as Listener
 
     return () => {
       connectedListener.off()