nodejs gremlin update if exist or else create

Question

I am using nodejs gremlin against AWS neptune, the requirement is to update properties if vertice exist, or else, create a new vertice, i tried below

g.V().has('event','id','1').
  fold().
  coalesce(unfold(),
           addV('event').property('id','1'))

but I got 'unfold is not defined' error, how do I resolve this?

Answer 1

You probably just need to import unfold() properly. Some common imports for working with Gremlin can be found here but in your case I think you just need to do:

const __ = gremlin.process.statics

and then refer to unfold() as __.unfold() - or just import unfold() as a function explicitly to use it as you were using it.