Rails Routes缺少资源发布路由的前缀

Question

I created a new controller and actions for a new model. I have setup the rails routes like below:

namespace :api do
    namespace :v1 do
      resources :universes
    end
  end

I am trying to write up some RSpec tests using the path helpers (ex. get(api_v1_universe_path(universe.id)) ). When I go to look at the post route for invites the route is missing the prefix as shown here:

                                         POST     /api/v1/universes(.:format)                                                                       api/v1/universes#create
                     new_api_v1_universe GET      /api/v1/universes/new(.:format)                                                                   api/v1/universes#new
                    edit_api_v1_universe GET      /api/v1/universes/:id/edit(.:format)                                                              api/v1/universes#edit
                         api_v1_universe GET      /api/v1/universes/:id(.:format)                                                                   api/v1/universes#show

I know I can manually add a line like post "/", to: "universe#create", as: "create" to get a route with a prefix. However, I wanted to know what was causing prefix to be missing from the post route so I can possibly fix that instead?