ActionController::UrlGenerationError:
   No route matches {:action=>"create", :controller=>"user/registrations", :user=>{:name=>"Adriane Koepp", :city=>"Nidiafurt", :address=>"14955 Cormier Viaduct", :country=>"Mozambique", :email=>"moshe@kozey.com", :phone_primary=>"(295) 491-0447 x9108", :phone_secondary=>"536.985.9499 x7264", :postal_code=>"93438-7448", :province=>"South Carolina", :password=>"MaH9R5G8XqB", :pets_attributes=>[{:name=>"Patches", :chip_number=>"149793073311890", :species=>"iusto"}]}}

it 'creates a new User' do
  expect do
    post :create, params: { user: valid_attributes }
  end.to change(User, :count).by(1)
end

devise_for :users, controllers: {
  registration: 'user/registration'
}

1) User::RegistrationsController POST #create with valid params creates a new User
     Failure/Error: post :create, params: { user: valid_attributes }

     AbstractController::ActionNotFound:
       Could not find devise mapping for path "/users".
       This may happen for two reasons:

       1) You forgot to wrap your route inside the scope block. For example:

         devise_scope :user do
           get "/some/route" => "some_devise_controller"
         end

       2) You are testing a Devise controller bypassing the router.
          If so, you can explicitly tell Devise which mapping to use:

          @request.env["devise.mapping"] = Devise.mappings[:user]

# routes.rb
devise_for :users, controllers: {
  registrations: 'user/registrations'
}