while updating the model getting validationException

[LovikaJ]

I am migrating from vogels to dynogels and while updating the model I am getting this error:
ValidationException: Invalid UpdateExpression: An expression attribute value used in expression is not defined; attribute value: :ip

I debugged it and found that after I use set session.set(token: token, ip:sourceip) and then use session.updateAsync() it throws the mentioned error.

my test case fails only when I am not passing value to ip. this used to work fine in vogels. I checked and found that in models attributes I don't get the field which is undefined but in case of dynogels I am getting it in the model attribute

vogels:
{ createdAt: '2019-02-21T07:05:13.640Z'}

dynogels:
{createdAt: '2019-02-21T10:42:01.958Z',ip: undefined}

[rchl]

I believe it's the update validation. There is PR to remove it (#129) but author of this project is MIA.