Rails controller actions ordering convention

Rails scaffold generates the controller actions in this order:

index
show
new
edit
create
update
destroy

GET requests are before the non-GET ones. Not a strict CRUD order but I find it intuitive and easy to follow. (Check the source code.)

Some people (including me) also prefer pairing new and create, edit and update together as they are more related to each other.

index
show
new
create
edit
update
destroy

I also like to apply either of this order to places where we need to specify some of the actions, such as routes and before_actions.

For example:

# 🙅 Bad
resources :follow, only: %i[destroy create]
namespace :admin do
  resources :posts, only: %i[show index update]
end

# 👍 Good
resources :follow, only: %i[create destroy]
namespace :admin do
  resources :posts, only: %i[index show update]
end

# 🙅 Bad
before_action :require_login, only: %i[update destroy edit]

# 👍 Good
before_action :require_login, only: %i[edit update destroy]

Is there a Rubocop to ensure the action order?

I've seen many codebases don't have any sort of ordering conventions. Sometimes I encounter a destroy and then create. Lacking consistensy makes it hard to navigate the codebase. So I was wondering if there is a Rubocop that checks the controller actions ordering.

Turns out there is a PR https://github.com/rubocop/rubocop-rails/pull/547! 🎉

As of the time of writing (Jan 2022), it's still not merged yet but seems promising. 🙂

Looking at its current implementation, this cop Rubocop::Cop::Rails::ActionOrder will be disabled by default, understandably. The default order follows Rails scaffold and is also configurable. Nice!

Looking forward to that PR gets merged. 😄