app/views/json/password_attack/users.erb
"password_attack": {
<% unless @users.empty? -%>
<% last_index = @users.size - 1 -%>
<% @users.each_with_index do |user, index| -%>
<%= user.username.to_json %>: {
"password": <%= user.password.to_json %>
}<% unless index == last_index -%>,<% end -%>
<% end -%>
<% end -%>
},