Does anybody know how to validate the document before allowing publication?

Hi!I am using a document workflow based on
https://github.com/sanity-io/demo-custom-workflow .In this the publish action defined in publish.js, publishes via the following line:

ops.publish.execute()

But it seems that this publishes without validating the document at hand.

Does anybody know how to validate the document before allowing publication?

there's also a validation hook iirc

Perfect, just what I was looking for - thanks!