/// TEST: Expected error with code and message
/// EXPECT: PASS
/// EXPLAIN: UnaryError
--- ENDPOINT ---
auth.AuthService/Login

--- REQUEST ---
{
  "username": "",
  "password": ""
}

--- ERROR ---
{
  "code": 3,
  "message": "Username and password required"
}

--- ASSERTS ---
.code == 3
.message contains "Username"
