According to the current design (when you edit to the same name/ add the same name), duplication is not allowed. So no 2 users should be able to have the same name.
Actual:
Duplicated users are allowed if you edit the JSON.
Steps to reproduce:
Edit the json, copy a person and add a space behind their name.
Startup the app as per normal. Despite the invalid data, the app does not reject it and instead allows the invalid data.
Expected:
Actual:
Steps to reproduce: