Cloud events incorrectly unmarshalled: first argument is undefined, 2nd argument differs from production

When Pubsub notifications are sent to a locally hosted cloud event function, the first argument is undefined. It should contain the event information. The 2nd argument though present, does not match production signature; rather than containing metadata about the notification, it contains the entire event object, which should be the contents of argument 1 instead.

My dummy cloud events function:

exports.helloEvents = (data, context) => {
  console.log(data);
  console.log(context);
};

Pub/sub notification being sent:

{
  "subscription": "projects/myproj/subscriptions/mysub",
  "message": {
    "data": "...my base 64 encoded data...",
    "messageId": "1",
    "attributes": {}
  }
}

helloEvents log in production:

Argument 1, data, is:

{  
   "subscription":"projects/myproj/subscriptions/mysub",
   "message":{  
      "data":"...my base 64 encoded data...",
      "messageId":"1",
      "attributes":{}
   }
}

Argument 2, context, is:

{  
   "eventId":"12032d95-089a-4663-9be5-8aafd9d4c623",
   "resource":{  
      "service":"pubsub.googleapis.com",
      "name":"projects/myproj/topics/mytopic"
   },
   "eventType":"google.pubsub.topic.publish",
   "timestamp":"2019-06-16T18:39:44.809Z"
}

On local, the results I get is very different.

• Argument 1: undefined
• Argument 2:

{  
   "subscription":"projects/myproj/subscriptions/mysub",
   "message":{  
      "data":"...my base 64 encoded data...",
      "messageId":"1",
      "attributes":{}
   }
}

[grant]

Hey all, thanks for the comments. I know this is an issue. I’m not sure of the exact solution right now.

We’re formally supporting CloudEvents in the Functions Framework spec and will be looking at better, more accurate support for CloudEvents (and legacy events) in the frameworks.

I’ve pinged a colleague to see if we can also improve our docs on cloud.google.com

In any case, this whole section seems to be flat wrong, because following the approach simply doesn’t work.

I’ve removed that section until we have accurate docs.

[mykwillis]

@alexsanzdev the tests pass, but I don’t believe that they are terribly comprehensive. There is no test data that looks anything like the Cloud Pub/Sub request.

Incidentally, there is test data named “GCF legacy event” that looks like this:

      name: 'GCF legacy event',
      body: {
        eventId: 'testEventId',
        timestamp: 'testTimestamp',
        eventType: 'testEventType',
        resource: 'testResource',
        data: { some: 'payload' },
      },
      expectedResource: 'testResource',
    },

So it seems like maybe there should be a test for the PubSub event format, and the associated fix to pull data from correct place, but I’m still stuck scratching my head asking how this works on GCF production.

In any case, this whole section seems to be flat wrong, because following the approach simply doesn’t work.