A blank or empty rule assignment is getting creating i.e we are able to create the empty rule assignment without policy name and identity pattern.
Steps to Reproduce:
Login to zanata using admin.
Click on admin tab from left panel.
Select "Role Assignment Rule".
Click on "..." to create new role assignment.
Do not select any policy.
Do not enter anything in identity pattern.
Click on save.
Blank/empty rule assignment is created.
There should be an compulsory fields while adding new rule assignment.
If there fields are optional. then optional should be written in front of them
Attached screen captured for more ref.