Allow to unbind events when closing a WebSocket connection, see #108

Main use case is suppressing further log messages from old WebSocket
connections when the application has already discarded it. The main
problem of #108 remains unresolved (race condition).

Author: lgrahl

saltyrtc-client.d.ts

@@ -236,7 +236,7 @@ declare namespace saltyrtc {
         decryptFromPeer(box: Box): Uint8Array;
 
         connect(): void;
-        disconnect(): void;
+        disconnect(unbind?: boolean): void;
 
         sendApplicationMessage(data: any): void;
 

src/client.ts

@@ -456,10 +456,11 @@ class SaltyRTC implements saltyrtc.SaltyRTC {
      * Both the WebSocket as well as any open task connection will be closed.
      *
      * This method is asynchronous. To get notified when the connection is has
-     * been closed, subscribe to the `connection-closed` event.
+     * been closed, subscribe to the `connection-closed` event. To silence
+     * further events from the underlying connection, set `unbind` to `true`.
      */
-    public disconnect(): void {
-        this.signaling.disconnect();
+    public disconnect(unbind = false): void {
+        this.signaling.disconnect(unbind);
     }
 
     /**

src/signaling/common.ts

@@ -91,7 +91,7 @@ export abstract class Signaling implements saltyrtc.Signaling {
         }
         this.handoverState.onBoth = () => {
             this.client.emit({type: 'handover'});
-            this.ws.close(CloseCode.Handover);
+            this.closeWebsocket(CloseCode.Handover);
         };
     }
 
@@ -161,8 +161,10 @@ export abstract class Signaling implements saltyrtc.Signaling {
 
     /**
      * Disconnect from the signaling server.
+     *
+     * @param unbind Whether to unbind all WebSocket events.
      */
-    public disconnect(): void {
+    public disconnect(unbind = false): void {
         const reason = CloseCode.ClosingNormal;
 
         // Update state
@@ -173,12 +175,8 @@ export abstract class Signaling implements saltyrtc.Signaling {
             this.sendClose(reason);
         }
 
-        // Close WebSocket instance
-        if (this.ws !== null) {
-            console.debug(this.logTag, 'Disconnecting WebSocket');
-            this.ws.close(reason);
-        }
-        this.ws = null;
+        // Close WebSocket instance and unbind all events
+        this.closeWebsocket(reason, undefined, unbind);
 
         // Close task connections
         if (this.task !== null) {
@@ -191,7 +189,45 @@ export abstract class Signaling implements saltyrtc.Signaling {
     }
 
     /**
-     * Return connection path for websocket.
+     * Close the WebSocket connection.
+     *
+     * @param code The close code.
+     * @param reason The close reason.
+     * @param unbind Whether to unbind all events. This will move the Signaling
+     *   instance into the `closed` state.
+     */
+    private closeWebsocket(code?: number, reason?: string, unbind = false): void {
+        if (this.ws !== null) {
+            // Drop internal close codes
+            // see: https://github.com/saltyrtc/saltyrtc-meta/issues/110
+            if (code === undefined || code <= 3000) {
+                code = CloseCode.ClosingNormal;
+            }
+
+            // Disconnect
+            console.debug(this.logTag, `Disconnecting WebSocket, close code: ${code}`);
+            this.ws.close(code, reason);
+
+            // Unbind events?
+            if (unbind) {
+                this.ws.removeEventListener('open', this.onOpen);
+                this.ws.removeEventListener('error', this.onError);
+                this.ws.removeEventListener('close', this.onClose);
+                this.ws.removeEventListener('message', this.onMessage);
+            }
+
+            // Forget instance
+            this.ws = null;
+
+            // Move into closed state (if necessary)
+            if (unbind) {
+                this.setState('closed');
+            }
+        }
+    }
+
+    /**
+     * Return connection path for WebSocket.
      */
     protected abstract getWebsocketPath(): string;
 
@@ -246,30 +282,6 @@ export abstract class Signaling implements saltyrtc.Signaling {
                                       ' (' + explainCloseCode(ev.code) + ')');
             this.setState('closed');
             this.client.emit({type: 'connection-closed', data: ev.code});
-            const logError = (reason: string) => console.error(this.logTag, 'Websocket close reason:', reason);
-            switch (ev.code) {
-                case CloseCode.GoingAway:
-                    logError('Server is being shut down');
-                    break;
-                case CloseCode.NoSharedSubprotocol:
-                    logError('No shared sub-protocol could be found');
-                    break;
-                case CloseCode.PathFull:
-                    logError('Path full (no free responder byte)');
-                    break;
-                case CloseCode.ProtocolError:
-                    logError('Protocol error');
-                    break;
-                case CloseCode.InternalError:
-                    logError('Internal error');
-                    break;
-                case CloseCode.DroppedByInitiator:
-                    logError('Dropped by initiator');
-                    break;
-                case CloseCode.InvalidKey:
-                    logError('Invalid server key');
-                    break;
-            }
         }
     }
 
@@ -915,19 +927,11 @@ export abstract class Signaling implements saltyrtc.Signaling {
      * - Set `this.ws` to `null`
      * - Set `this.status` to `new`
      * - Reset the server combined sequence
+     * - Unbind all events
      */
     public resetConnection(reason?: number): void {
         // Close WebSocket instance
-        if (this.ws !== null) {
-            console.debug(this.logTag, 'Disconnecting WebSocket (close code ' + reason + ')');
-            if (reason === CloseCode.GoingAway) {
-                // See https://github.com/saltyrtc/saltyrtc-meta/pull/111/
-                this.ws.close();
-            } else {
-                this.ws.close(reason);
-            }
-        }
-        this.ws = null;
+        this.closeWebsocket(reason, undefined, true);
 
         // Reset
         this.server = new Server();

tests/integration.spec.ts

@@ -340,11 +340,19 @@ export default () => { describe('Integration Tests', function() {
 
         spec = it('send connection-closed event only once', async (done) => {
             console.info('===> TEST NAME:', spec.getFullName());
+            const initiator = new SaltyRTCBuilder()
+                .connectTo(Config.SALTYRTC_HOST, Config.SALTYRTC_PORT)
+                .withKeyStore(new KeyStore())
+                .usingTasks([new DummyTask()])
+                .withServerKey(Config.SALTYRTC_SERVER_PUBLIC_KEY)
+                .asInitiator();
             let count = 0;
-            this.initiator.on('connection-closed', (ev) => count += 1);
-            this.initiator.connect();
+            initiator.on('connection-closed', (ev) => {
+                count += 1
+            });
+            initiator.connect();
             await sleep(100);
-            this.initiator.signaling.resetConnection(3001);
+            (initiator as any).signaling.closeWebsocket(3001);
             await sleep(100);
             expect(count).toEqual(1);
             done();