feat(rpc): client.transporter.errored subject

With this change it is possible to subscribe to onError events from the transporter and get the actual error object.

packages/rpc-tcp/src/client.ts

@@ -30,6 +30,7 @@ export class RpcTcpClientAdapter implements ClientTransportAdapter {
         });
 
         socket.on('error', (error: any) => {
+            error = error instanceof Error ? error : new Error(String(error));
             connection.onError(error);
         });
 

packages/rpc/src/client/client.ts

@@ -71,7 +71,7 @@ export interface TransportConnectionHooks {
 
     onData(buffer: Uint8Array, bytes?: number): void;
 
-    onError(error: any): void;
+    onError(error: Error): void;
 }
 
 export interface ClientTransportAdapter {
@@ -88,7 +88,7 @@ export interface WritableClient {
             connectionId?: number,
             peerId?: string,
             timeout?: number
-        }
+        },
     ): RpcMessageSubject;
 }
 
@@ -122,19 +122,34 @@ export class RpcClientTransporter {
     public id?: Uint8Array;
 
     /**
-     * true when the connection fully established (after authentication)
+     * When the connection is established (including handshake and authentication).
      */
     public readonly connection = new BehaviorSubject<boolean>(false);
+
+    /**
+     * When the connection was reconnected. This is not called for the very first connection.
+     */
     public readonly reconnected = new Subject<number>();
+
+    /**
+     * When the connection was disconnected (due to error or close).
+     * This increases the connectionId by one.
+     */
     public readonly disconnected = new Subject<number>();
 
+    /**
+     * Triggered for any onError call from the transporter.
+     * Right after this event, onDisconnect is called (and thus connection.next(false) and disconnected.next()).
+     */
+    public readonly errored = new Subject<{ connectionId: number, error: Error }>();
+
     public reader = new RpcMessageReader(
         (v) => this.onMessage(v),
         (id) => {
             if (this.writer) {
                 this.writer.write(createRpcMessage(id, RpcTypes.ChunkAck));
             }
-        }
+        },
     );
 
     public constructor(
@@ -159,7 +174,14 @@ export class RpcClientTransporter {
         return this.connected;
     }
 
-    protected onError() {
+    protected onError(error: Error) {
+        if (this.connected) {
+            // We do not want to call errored if we are not yet connected,
+            // since errors thrown while in connection process are forwarded
+            // to the connection promise (and thus are thrown in connect()
+            // or in any rpc action).
+            this.errored.next({ connectionId: this.connectionId, error });
+        }
         this.onDisconnect();
     }
 
@@ -256,8 +278,8 @@ export class RpcClientTransporter {
                         resolve(undefined);
                     },
 
-                    onError: (error: Event) => {
-                        this.onError();
+                    onError: (error: Error) => {
+                        this.onError(error);
                         reject(new OfflineError(`Could not connect: ${formatError(error)}`));
                     },
 
@@ -315,7 +337,10 @@ export class RpcClientPeer {
 
     }
 
-    public controller<T>(nameOrDefinition: string | ControllerDefinition<T>, options: { timeout?: number, dontWaitForConnection?: true } = {}): RemoteController<T> {
+    public controller<T>(nameOrDefinition: string | ControllerDefinition<T>, options: {
+        timeout?: number,
+        dontWaitForConnection?: true
+    } = {}): RemoteController<T> {
         const controller = new RpcControllerState('string' === typeof nameOrDefinition ? nameOrDefinition : nameOrDefinition.path);
         controller.peerId = this.peerId;
 
@@ -324,7 +349,7 @@ export class RpcClientPeer {
                 return (...args: any[]) => {
                     return this.actionClient.action(controller, propertyName as string, args, options);
                 };
-            }
+            },
         }) as any as RemoteController<T>;
     }
 
@@ -335,8 +360,12 @@ export class RpcClientPeer {
 
 
 export type RpcEventMessage = { id: number, date: Date, type: number, body: any };
-export type RpcClientEventIncomingMessage = { event: 'incoming', composite: boolean, messages: RpcEventMessage[] } & RpcEventMessage;
-export type RpcClientEventOutgoingMessage = { event: 'outgoing', composite: boolean, messages: RpcEventMessage[] } & RpcEventMessage;
+export type RpcClientEventIncomingMessage =
+    { event: 'incoming', composite: boolean, messages: RpcEventMessage[] }
+    & RpcEventMessage;
+export type RpcClientEventOutgoingMessage =
+    { event: 'outgoing', composite: boolean, messages: RpcEventMessage[] }
+    & RpcEventMessage;
 
 export type RpcClientEvent = RpcClientEventIncomingMessage | RpcClientEventOutgoingMessage;
 
@@ -355,7 +384,7 @@ export class RpcBaseClient implements WritableClient {
     public events = new Subject<RpcClientEvent>();
 
     constructor(
-        protected transport: ClientTransportAdapter
+        protected transport: ClientTransportAdapter,
     ) {
         this.transporter = new RpcClientTransporter(this.transport);
         this.transporter.onMessage = this.onMessage.bind(this);
@@ -443,7 +472,7 @@ export class RpcBaseClient implements WritableClient {
             connectionId?: number,
             peerId?: string,
             timeout?: number
-        } = {}
+        } = {},
     ): RpcMessageSubject {
         const resolvedSchema = schema ? resolveReceiveType(schema) : undefined;
         if (body && !schema) throw new Error('Body given, but not type');
@@ -452,15 +481,15 @@ export class RpcBaseClient implements WritableClient {
         const dontWaitForConnection = !!options.dontWaitForConnection;
         // const timeout = options && options.timeout ? options.timeout : 0;
 
-        const continuation = <T>(type: number, body?: T, schema?: ReceiveType<T>,) => {
+        const continuation = <T>(type: number, body?: T, schema?: ReceiveType<T>) => {
             if (connectionId === this.transporter.connectionId) {
                 //send a message with the same id. Don't use sendMessage() again as this would lead to a memory leak
                 // and a new id generated. We want to use the same id.
                 if (this.events.observers.length) {
                     this.events.next({
                         event: 'outgoing',
                         date: new Date,
-                        id, type, body, messages: [], composite: false
+                        id, type, body, messages: [], composite: false,
                     });
                 }
                 const message = createRpcMessage(id, type, body, undefined, schema);
@@ -488,7 +517,7 @@ export class RpcBaseClient implements WritableClient {
                 this.events.next({
                     event: 'outgoing',
                     date: new Date,
-                    id, type, body, messages: [], composite: false
+                    id, type, body, messages: [], composite: false,
                 });
             }
 
@@ -505,14 +534,14 @@ export class RpcBaseClient implements WritableClient {
                         this.events.next({
                             event: 'outgoing',
                             date: new Date,
-                            id, type, body, messages: [], composite: false
+                            id, type, body, messages: [], composite: false,
                         });
                     }
                     this.transporter.send(message, progress?.upload);
                 },
                 (e) => {
                     subject.next(new ErroredRpcMessage(id, e));
-                }
+                },
             );
         }
 
@@ -586,7 +615,7 @@ export class RpcClient extends RpcBaseClient {
                     write: (answer: Uint8Array) => {
                         //should we modify the package?
                         this.transporter.send(answer);
-                    }
+                    },
                 };
 
                 //todo: set up timeout for idle detection. Make the timeout configurable
@@ -614,7 +643,7 @@ export class RpcClient extends RpcBaseClient {
                         },
                         bufferedAmount: () => {
                             return this.transporter.bufferedAmount();
-                        }
+                        },
                     });
                     // Important to disable since transporter.send chunks already,
                     // otherwise data is chunked twice and protocol breaks.
@@ -667,7 +696,7 @@ export class RpcClient extends RpcBaseClient {
             deregister: async () => {
                 await this.sendMessage<rpcPeerDeregister>(RpcTypes.PeerDeregister, { id }).firstThenClose(RpcTypes.Ack);
                 this.registeredAsPeer = undefined;
-            }
+            },
         };
     }
 
@@ -689,7 +718,11 @@ export class RpcClient extends RpcBaseClient {
         return peer;
     }
 
-    public controller<T>(nameOrDefinition: string | ControllerDefinition<T>, options: { timeout?: number, dontWaitForConnection?: true, typeReuseDisabled?: boolean } = {}): RemoteController<T> {
+    public controller<T>(nameOrDefinition: string | ControllerDefinition<T>, options: {
+        timeout?: number,
+        dontWaitForConnection?: true,
+        typeReuseDisabled?: boolean
+    } = {}): RemoteController<T> {
         const controller = new RpcControllerState('string' === typeof nameOrDefinition ? nameOrDefinition : nameOrDefinition.path);
 
         options = options || {};
@@ -702,7 +735,7 @@ export class RpcClient extends RpcBaseClient {
                 return (...args: any[]) => {
                     return this.actionClient.action(controller, propertyName as string, args, options);
                 };
-            }
+            },
         }) as any as RemoteController<T>;
     }
 

packages/rpc/tests/connection.spec.ts

@@ -0,0 +1,50 @@
+import { expect, test } from '@jest/globals';
+import { RpcKernel } from '../src/server/kernel.js';
+import { RpcClient, TransportConnectionHooks } from '../src/client/client.js';
+
+test('connect', async () => {
+    const kernel = new RpcKernel();
+
+    const connections: TransportConnectionHooks[] = [];
+
+    const client = new RpcClient({
+        connect(connection: TransportConnectionHooks) {
+            const kernelConnection = kernel.createConnection({
+                write: (buffer) => connection.onData(buffer),
+                close: () => {
+                    connection.onClose();
+                },
+            });
+
+            connections.push(connection);
+
+            connection.onConnected({
+                clientAddress: () => {
+                    return 'direct';
+                },
+                bufferedAmount(): number {
+                    return 0;
+                },
+                close() {
+                    kernelConnection.close();
+                },
+                send(buffer) {
+                    kernelConnection.feed(buffer);
+                },
+            });
+        },
+    });
+
+    const errors: Error[] = [];
+    client.transporter.errored.subscribe((error) => {
+        errors.push(error.error);
+    });
+
+    await client.connect();
+    expect(client.transporter.isConnected()).toBe(true);
+    expect(connections).toHaveLength(1);
+
+    connections[0].onError(new Error('test'));
+    expect(errors[0].message).toEqual('test');
+    expect(client.transporter.isConnected()).toBe(false);
+});

packages/rpc/tests/custom-message.spec.ts

@@ -56,13 +56,13 @@ test('back controller', async () => {
 
     const client = new DirectClient(kernel);
 
-    // This wait for the server's Ack
+    // This waits for the server's Ack
     const answer = await client
         .sendMessage(MyTypes.QueryAndAnswer)
         .firstThenClose<{ v: string }>(MyTypes.Answer);
     expect(answer.v).toBe('42 is the answer');
 
-    // This wait for the server's Ack
+    // This waits for the server's Ack
     await client
         .sendMessage<{v: string}>(MyTypes.BroadcastWithAck, {v: 'Hi1'})
         .ackThenClose();