Loading collection data...
Collections are a way for you to organize kata so that you can create your own training routines. Every collection you create is public and automatically sharable with other warriors. After you have added a few kata to a collection you and others can train on the kata contained within the collection.
Get started now by creating a new collection.
I am having the same exact issue. I am returning EmptyNode from the tail as tiagorg suggested. I used narve's test specs above with an additional one shown below to make sure it was the empty node from the tail.
Any other ideas about why it might not be passing?