Rails same route (POST /users) for different controller actions [Devise] - ruby-on-rails

Question

I have a rails api application where I am using Devise gem for user management. I created a user model off the devise gem. After that, I noticed that I have two same routes listed in the rake routescommand. I want POST (/users) to call api/v1/users#create action first and then call devise/registrations#create.
user_registration POST /users(.:format) devise/registrations#create
api_users POST /users(.:format) api/v1/users#create {:format=>:json}
When I test POST (/users) using users_controller_spec file, api/v1/users#create action is called. However, when I do a POST (/users) using POSTMAN, the logs indicates that devise/registrations#createaction is called instead.
How do I correct this so that the POST (/users) I do using POSTMAN or curl calls api/v1/users#create first to create the user model and then calls devise/registrations#create to register the user?
I am not 100% sure how devise works so any help here would be helpful.
This is my config/routes.rb
Rails.application.routes.draw do
devise_for :users
# Api definition
namespace :api, defaults: { format: :json }, path: '/' do
scope module: :v1, constraints: ApiConstraints.new(version: 1, default: true) do
# We are going to list our resources here
resources :users, only: [:show, :create, :update, :destroy]
resources :sessions, only: [:create, :destroy]
end
end
end

Answer 1

So, the thing with Rails Routes is, when you make a request, routes are checked as they are defined in the routes.rb from top to bottom.
Now, when you make a request via POSTMAN, the /users path matches with a path generated via devise_for, as it is the first line in the file.
Now, when you are writing tests for the controller, you are not really accessing /users, you are just telling the api/v1/users_controller to invoke the create method, which is bound to hit the api/v1/users#create
Now, a way you can resolve this conflict is by changing what devise names its routes. If you do something like this:
Rails.application.routes.draw do
devise_for :users, path: 'customer'
# Api definition
namespace :api, defaults: { format: :json }, path: '/' do
scope module: :v1, constraints: ApiConstraints.new(version: 1, default: true) do
# We are going to list our resources here
resources :users, only: [:show, :create, :update, :destroy]
resources :sessions, only: [:create, :destroy]
end
end
end
This is what the devise routes will be:
new_user_session GET /customer/sign_in(.:format) devise/sessions#new
user_session POST /customer/sign_in(.:format) devise/sessions#create
destroy_user_session DELETE /customer/sign_out(.:format) devise/sessions#destroy
user_password POST /customer/password(.:format) devise/passwords#create
new_user_password GET /customer/password/new(.:format) devise/passwords#new
edit_user_password GET /customer/password/edit(.:format) devise/passwords#edit
...