Use Tag Namespace

Prepare

Add this line to your application’s Gemfile:

group :development do
  gem 'r2-oas'
end

Add the following settings to your rails project’s config/environments/development.rb.

require 'r2-oas'

R2OAS.configure do |config|
 config.use_tag_namespace    = true
end

Command

$ bundle exec rake routes:oas:docs

Example

if there is routing like this:

$ bundle exec  rake routes
          Prefix Verb   URI Pattern                      Controller#Action
     rails_admin        /admin                           RailsAdmin::Engine
    api_v2_posts GET    /api/v2/posts(.:format)          api/v2/posts#index {:format=>:json}
                 POST   /api/v2/posts(.:format)          api/v2/posts#create {:format=>:json}
 new_api_v2_post GET    /api/v2/posts/new(.:format)      api/v2/posts#new {:format=>:json}
edit_api_v2_post GET    /api/v2/posts/:id/edit(.:format) api/v2/posts#edit {:format=>:json}
     api_v2_post GET    /api/v2/posts/:id(.:format)      api/v2/posts#show {:format=>:json}
                 PATCH  /api/v2/posts/:id(.:format)      api/v2/posts#update {:format=>:json}
                 PUT    /api/v2/posts/:id(.:format)      api/v2/posts#update {:format=>:json}
                 DELETE /api/v2/posts/:id(.:format)      api/v2/posts#destroy {:format=>:json}
    api_v1_posts GET    /api/v1/posts(.:format)          api/v1/posts#index
                 POST   /api/v1/posts(.:format)          api/v1/posts#create
 new_api_v1_post GET    /api/v1/posts/new(.:format)      api/v1/posts#new
edit_api_v1_post GET    /api/v1/posts/:id/edit(.:format) api/v1/posts#edit
     api_v1_post GET    /api/v1/posts/:id(.:format)      api/v1/posts#show
                 PATCH  /api/v1/posts/:id(.:format)      api/v1/posts#update
                 PUT    /api/v1/posts/:id(.:format)      api/v1/posts#update
                 DELETE /api/v1/posts/:id(.:format)      api/v1/posts#destroy
    api_v1_tasks GET    /api/v1/tasks(.:format)          api/v1/tasks#index
                 POST   /api/v1/tasks(.:format)          api/v1/tasks#create
 new_api_v1_task GET    /api/v1/tasks/new(.:format)      api/v1/tasks#new
edit_api_v1_task GET    /api/v1/tasks/:id/edit(.:format) api/v1/tasks#edit
     api_v1_task GET    /api/v1/tasks/:id(.:format)      api/v1/tasks#show
                 PATCH  /api/v1/tasks/:id(.:format)      api/v1/tasks#update
                 PUT    /api/v1/tasks/:id(.:format)      api/v1/tasks#update
                 DELETE /api/v1/tasks/:id(.:format)      api/v1/tasks#destroy
           tasks GET    /tasks(.:format)                 tasks#index
                 POST   /tasks(.:format)                 tasks#create
        new_task GET    /tasks/new(.:format)             tasks#new
       edit_task GET    /tasks/:id/edit(.:format)        tasks#edit
            task GET    /tasks/:id(.:format)             tasks#show
                 PATCH  /tasks/:id(.:format)             tasks#update
                 PUT    /tasks/:id(.:format)             tasks#update
                 DELETE /tasks/:id(.:format)             tasks#destroy
           users GET    /users(.:format)                 users#index
                 POST   /users(.:format)                 users#create
        new_user GET    /users/new(.:format)             users#new
       edit_user GET    /users/:id/edit(.:format)        users#edit
            user GET    /users/:id(.:format)             users#show
                 PATCH  /users/:id(.:format)             users#update
                 PUT    /users/:id(.:format)             users#update
                 DELETE /users/:id(.:format)             users#destroy

Routes for RailsAdmin::Engine:
  dashboard GET         /                                      rails_admin/main#dashboard
      index GET|POST    /:model_name(.:format)                 rails_admin/main#index
        new GET|POST    /:model_name/new(.:format)             rails_admin/main#new
     export GET|POST    /:model_name/export(.:format)          rails_admin/main#export
bulk_delete POST|DELETE /:model_name/bulk_delete(.:format)     rails_admin/main#bulk_delete
bulk_action POST        /:model_name/bulk_action(.:format)     rails_admin/main#bulk_action
       show GET         /:model_name/:id(.:format)             rails_admin/main#show
       edit GET|PUT     /:model_name/:id/edit(.:format)        rails_admin/main#edit
     delete GET|DELETE  /:model_name/:id/delete(.:format)      rails_admin/main#delete
show_in_app GET         /:model_name/:id/show_in_app(.:format) rails_admin/main#show_in_app

Generate like this:

oas_docs
├── schema
│   ├── components
│   │   └── schemas
│   │       ├── api
│   │       │   ├── v1
│   │       │   │   ├── post.yml
│   │       │   │   └── task.yml
│   │       │   └── v2
│   │       │       └── post.yml
│   │       ├── rails_admin
│   │       │   ├── engine.yml
│   │       │   └── main.yml
│   │       ├── task.yml
│   │       └── user.yml
│   ├── externalDocs.yml
│   ├── info.yml
│   ├── openapi.yml
│   ├── paths
│   │   ├── api
│   │   │   ├── v1
│   │   │   │   ├── post.yml
│   │   │   │   └── task.yml
│   │   │   └── v2
│   │   │       └── post.yml
│   │   ├── rails_admin
│   │   │   ├── engine.yml
│   │   │   └── main.yml
│   │   ├── task.yml
│   │   └── user.yml
│   ├── servers.yml
│   └── tags.yml

Do not Use Tag Namespace

Prepare

require 'r2-oas'

R2OAS.configure do |config|
   config.use_tag_namespace = false
end

Command

$ bundle exec rake routes:oas:docs

Generate like this:

oas_docs
├── schema
    ├── components
    │   └── schemas
    │       ├── api
    │       │   ├── v1
    │       │   │   ├── post.yml
    │       │   │   └── task.yml
    │       │   └── v2
    │       │       └── post.yml
    │       ├── rails_admin
    │       │   ├── engine.yml
    │       │   └── main.yml
    │       ├── task.yml
    │       └── user.yml
    ├── externalDocs.yml
    ├── info.yml
    ├── openapi.yml
    ├── paths
    │   ├── engine.yml
    │   ├── main.yml
    │   ├── post.yml
    │   ├── task.yml
    │   └── user.yml
    ├── servers.yml
    └── tags.yml