alternate way of keeping ws up when no active tasks

lib/middleware.js

@@ -192,8 +192,8 @@ module.exports = function(srf, logger) {
       if (0 === app.tasks.length) throw new Error('no application provided');
       next();
     } catch (err) {
-      logger.info({err}, `Error retrieving or parsing application: ${err.message}`);
-      res.send(480, {headers: {'X-Reason': err.message}});
+      logger.info({err}, `Error retrieving or parsing application: ${err?.message}`);
+      res.send(480, {headers: {'X-Reason': err?.message || 'unknown'}});
     }
   }
 

lib/session/call-session.js

@@ -8,6 +8,7 @@ const makeTask = require('../tasks/make_task');
 const normalizeJambones = require('../utils/normalize-jambones');
 const listTaskNames = require('../utils/summarize-tasks');
 const HttpRequestor = require('../utils/http-requestor');
+const WsRequestor = require('../utils/ws-requestor');
 const BADPRECONDITIONS = 'preconditions not met';
 const CALLER_CANCELLED_ERR_MSG = 'Response not sent due to unknown transaction';
 
@@ -291,6 +292,7 @@ class CallSession extends Emitter {
    */
   async exec() {
     this.logger.info({tasks: listTaskNames(this.tasks)}, `CallSession:exec starting ${this.tasks.length} tasks`);
+
     while (this.tasks.length && !this.callGone) {
       const taskNum = ++this.taskIdx;
       const stackNum = this.stackIdx;
@@ -304,13 +306,22 @@ class CallSession extends Emitter {
         this.logger.info(`CallSession:exec completed task #${stackNum}:${taskNum}: ${task.name}`);
       } catch (err) {
         this.currentTask = null;
-        if (err.message.includes(BADPRECONDITIONS)) {
+        if (err.message?.includes(BADPRECONDITIONS)) {
           this.logger.info(`CallSession:exec task #${stackNum}:${taskNum}: ${task.name}: ${err.message}`);
         }
         else {
           this.logger.error(err, `Error executing task  #${stackNum}:${taskNum}: ${task.name}`);
           break;
         }
+
+        if (0 === this.tasks.length && this.hasStableDialog && this.requestor instanceof WsRequestor) {
+          try {
+            await this._awaitCommandsOrHangup();
+          } catch (err) {
+            this.logger.info(err, 'CallSession:exec - error waiting for new commands');
+            break;
+          }
+        }
       }
     }
 
@@ -370,6 +381,10 @@ class CallSession extends Emitter {
       this.currentTask.kill(this);
       this.currentTask = null;
     }
+    if (this.wakeupResolver) {
+      this.wakeupResolver();
+      this.wakeupResolver = null;
+    }
   }
 
   /**
@@ -620,7 +635,7 @@ class CallSession extends Emitter {
   }
 
   _onCommand({msgid, command, queueCommand, data}) {
-    this.logger.info({msgid, command, data}, 'CallSession:_onCommand - received command');
+    this.logger.info({msgid, command, queueCommand, data}, 'CallSession:_onCommand - received command');
     switch (command) {
       case 'redirect':
         if (Array.isArray(data)) {
@@ -665,6 +680,10 @@ class CallSession extends Emitter {
       default:
         this.logger.info(`CallSession:_onCommand - invalid command ${command}`);
     }
+    if (this.wakeupResolver) {
+      this.wakeupResolver();
+      this.wakeupResolver = null;
+    }
   }
 
   _evaluatePreconditions(task) {
@@ -1008,6 +1027,10 @@ class CallSession extends Emitter {
         this.emit('callStatusChange', {callStatus: CallStatus.Completed, duration});
         this.logger.debug('CallSession: call terminated by jambones');
         origDestroy();
+        if (this.wakeupResolver) {
+          this.wakeupResolver();
+          this.wakeupResolver = null;
+        }
       }
     };
   }
@@ -1076,6 +1099,13 @@ class CallSession extends Emitter {
     this.updateCallStatus(Object.assign({}, this.callInfo.toJSON()), this.serviceUrl)
       .catch((err) => this.logger.error(err, 'redis error'));
   }
+
+  _awaitCommandsOrHangup() {
+    assert(!this.wakeupResolver);
+    return new Promise((resolve, reject) => {
+      this.wakeupResolver = resolve;
+    });
+  }
 }
 
 module.exports = CallSession;