Transit to a new state inside a callback using Machina.js

I am using machina.js library in my nodejs server. I run the State Machine when a GET request is done and I use the State Machine to determine the response to provide to the client.

I have not clear how to manage my FSM if in a certain state I have to: 1) wait to get some information from a third party web-server; 2) transit to a new state which will get the data returned by third party web-server.

Look at following code:

const soap = require('./soap-interface');
const machina = require('machina');
var express = require('express');
var app = express();

app.get('/', determine);

app.listen(3000, function () {
  console.log('Example app listening on port 3000!')
});


function determine(req, res) {
  const jsonData = req.body;

  const FSM = new machina.BehavioralFsm({
    namespace: 'action',
    initialState: 'uninitialized',
    states: {
      uninitialized: {
        '*': function (email) {
          this.deferUntilTransition(email);
          this.transition(email, 'checkStatus');
        }
      },
      checkStatus: {
        _onEnter(email) {
          const that = this;
          const action = 'GetStatus';
          const params = [{ paramName: 'invoiceNumber', paramValue: email.InvoiceNumber }];
          // Make request to Soap service and await for callback with results
          soap.request(action, params, (output) => {
            console.log(output);
            // TODO: here I want to transit to a specific state
            if(output.isOverdue)
              that.transition(output, 'isOverdue');
            else
              that.transition(output, 'notOverdue');
          });
        }
      },
      isOverdue: {
        _onEnter(output) {
          const response = { status : 'overdue' };
          res.json(response);
        }
      },
      notOverdue: {
        _onEnter(output) {
          const response = { status : 'not overdue' };
          res.json(response);
        }
      }
    },
    runFSM(email) {
      console.log('============= START FSM =============');
      this.handle(email, '*');
      console.log('============= END FSM =============');
    }
  });

  FSM.runFSM(jsonData);
}

The error that I have got is - of course - the timeout. I mean, I terminate the function 'determine' before sending the json response.

via dventi3