Output for "waitFor" is executed twice

[AviFix]

Hi,

It seems that when I set the output for a "waitFor" step, the output function is being called twice;

Execution log:

Started workflow: c41127b43cef0
Waiting for event...
event function
Publishing event...
Published event
event function
The event data is hi!

The sample code:

const workflow_es = require('workflow-es');

class LogMessage extends workflow_es.StepBody {
  run(context) {
    console.log(this.message);
    return workflow_es.ExecutionResult.next();
  }
}


class EventSample_Workflow {
  constructor() {
    this.id = 'event-sample';
    this.version = 1;
  }

  build(builder) {
    builder
      .startWith(LogMessage)
      .input((step, data) => step.message = 'Waiting for event...')
      .waitFor('myEvent', (data) => '0')
      .output((step, data) => {
        console.log('event function');
        data.externalValue = step.eventData;
      })
      .then(LogMessage)
      .input((step, data) => step.message = 'The event data is ' + data.externalValue);
  }
}

async function main() {
  const config = workflow_es.configureWorkflow();
  const host = config.getHost();

  host.registerWorkflow(EventSample_Workflow);
  await host.start();

  let id = await host.startWorkflow('event-sample', 1, {});
  console.log('Started workflow: ' + id);

  await new Promise(resolve => setTimeout(() => resolve(), 5000));

  console.log('Publishing event...');
  await host.publishEvent('myEvent', '0', 'hi!', new Date());
  console.log('Published event');
}

main();

Thanks