chore(web): simplify websocket state machine

2 files changed, 17 insertions, 39 deletions

diff --git a/language-web/src/main/js/editor/XtextClient.ts b/language-web/src/main/js/editor/XtextClient.ts
index 5216154e..39458e93 100644
--- a/language-web/src/main/js/editor/XtextClient.ts
+++ b/language-web/src/main/js/editor/XtextClient.ts
@@ -223,7 +223,7 @@ export class XtextClient {
         this.pendingUpdate = null;
         switch (newStateId) {
           case UpdateAction.ForceReconnect:
-            this.webSocketClient.handleApplicationError();
+            this.webSocketClient.forceReconnectOnError();
             break;
           case UpdateAction.FullTextUpdate:
             await this.updateFullText();
diff --git a/language-web/src/main/js/editor/XtextWebSocketClient.ts b/language-web/src/main/js/editor/XtextWebSocketClient.ts
index 6766029b..489ac03d 100644
--- a/language-web/src/main/js/editor/XtextWebSocketClient.ts
+++ b/language-web/src/main/js/editor/XtextWebSocketClient.ts
@@ -15,12 +15,10 @@ const XTEXT_SUBPROTOCOL_V1 = 'tools.refinery.language.web.xtext.v1';
 
 const WEBSOCKET_CLOSE_OK = 1000;
 
-const RECONNECT_DELAY_MS = [1000, 5000, 30_000];
+const RECONNECT_DELAY_MS = [200, 1000, 5000, 30_000];
 
 const MAX_RECONNECT_DELAY_MS = RECONNECT_DELAY_MS[RECONNECT_DELAY_MS.length - 1];
 
-const MAX_APP_ERROR_COUNT = 1;
-
 const BACKGROUND_IDLE_TIMEOUT_MS = 5 * 60 * 1000;
 
 const PING_TIMEOUT_MS = 10 * 1000;
@@ -33,7 +31,7 @@ type PushHandler = (
   resourceId: string,
   stateId: string,
   service: string,
-  data: unknown
+  data: unknown,
 ) => Promise<void>;
 
 enum State {
@@ -59,8 +57,6 @@ export class XtextWebSocketClient {
 
   state = State.Initial;
 
-  appErrorCount = 0;
-
   reconnectTryCount = 0;
 
   idleTimer = new Timer(() => {
@@ -106,7 +102,7 @@ export class XtextWebSocketClient {
     this.connection.addEventListener('open', () => {
       if (this.connection.protocol !== XTEXT_SUBPROTOCOL_V1) {
         log.error('Unknown subprotocol', this.connection.protocol, 'selected by server');
-        this.handleProtocolError();
+        this.forceReconnectOnError();
       }
       if (document.visibilityState === 'hidden') {
         this.handleTabHidden();
@@ -115,7 +111,6 @@ export class XtextWebSocketClient {
       }
       log.info('Connected to websocket');
       this.nextMessageId = 0;
-      this.appErrorCount = 0;
       this.reconnectTryCount = 0;
       this.pingTimer.schedule();
       this.onReconnect().catch((error) => {
@@ -124,7 +119,7 @@ export class XtextWebSocketClient {
     });
     this.connection.addEventListener('error', (event) => {
       log.error('Unexpected websocket error', event);
-      this.handleProtocolError();
+      this.forceReconnectOnError();
     });
     this.connection.addEventListener('message', (event) => {
       this.handleMessage(event.data);
@@ -136,7 +131,7 @@ export class XtextWebSocketClient {
         return;
       }
       log.error('Websocket closed unexpectedly', event.code, event.reason);
-      this.handleProtocolError();
+      this.forceReconnectOnError();
     });
   }
 
@@ -158,13 +153,13 @@ export class XtextWebSocketClient {
   }
 
   private handleTabHidden() {
-    log.trace('Tab became hidden while websocket is connected');
+    log.debug('Tab hidden while websocket is connected');
     this.state = State.TabHiddenIdle;
     this.idleTimer.schedule();
   }
 
   private handleTabVisibleConnected() {
-    log.trace('Tab became visible while websocket is connected');
+    log.debug('Tab visible while websocket is connected');
     this.state = State.TabVisible;
   }
 
@@ -202,11 +197,11 @@ export class XtextWebSocketClient {
         this.pingTimer.schedule();
       } else {
         log.error('Invalid pong');
-        this.handleProtocolError();
+        this.forceReconnectOnError();
       }
     }).catch((error) => {
       log.error('Error while waiting for ping', error);
-      this.handleProtocolError();
+      this.forceReconnectOnError();
     });
   }
 
@@ -241,7 +236,7 @@ export class XtextWebSocketClient {
   private handleMessage(messageStr: unknown) {
     if (typeof messageStr !== 'string') {
       log.error('Unexpected binary message', messageStr);
-      this.handleProtocolError();
+      this.forceReconnectOnError();
       return;
     }
     log.trace('Incoming websocket message', messageStr);
@@ -250,7 +245,7 @@ export class XtextWebSocketClient {
       message = JSON.parse(messageStr);
     } catch (error) {
       log.error('Json parse error', error);
-      this.handleProtocolError();
+      this.forceReconnectOnError();
       return;
     }
     if (isOkResponse(message)) {
@@ -259,7 +254,7 @@ export class XtextWebSocketClient {
       this.rejectRequest(message.id, new Error(`${message.error} error: ${message.message}`));
       if (message.error === 'server') {
         log.error('Reconnecting due to server error: ', message.message);
-        this.handleApplicationError();
+        this.forceReconnectOnError();
       }
     } else if (isPushMessage(message)) {
       this.onPush(
@@ -272,7 +267,7 @@ export class XtextWebSocketClient {
       });
     } else {
       log.error('Unexpected websocket message', message);
-      this.handleProtocolError();
+      this.forceReconnectOnError();
     }
   }
 
@@ -301,33 +296,16 @@ export class XtextWebSocketClient {
     this.handleWaitingForDisconnect();
   }
 
-  private handleProtocolError() {
+  forceReconnectOnError(): void {
     if (this.isLogicallyClosed) {
       return;
     }
     this.abortPendingRequests();
-    this.closeConnection(1000, 'reconnecting due to protocol error');
-    log.error('Reconnecting after delay due to protocol error');
+    this.closeConnection(1000, 'reconnecting due to error');
+    log.error('Reconnecting after delay due to error');
     this.handleErrorState();
   }
 
-  handleApplicationError(): void {
-    if (this.isLogicallyClosed) {
-      return;
-    }
-    this.abortPendingRequests();
-    this.closeConnection(1000, 'reconnecting due to application error');
-    this.appErrorCount += 1;
-    if (this.appErrorCount <= MAX_APP_ERROR_COUNT) {
-      log.error('Immediately reconnecting due to application error');
-      this.state = State.Initial;
-      this.reconnect();
-    } else {
-      log.error('Reconnecting after delay due to application error');
-      this.handleErrorState();
-    }
-  }
-
   private abortPendingRequests() {
     this.pendingRequests.forEach((request) => {
       request.reject(new Error('Websocket disconnect'));