Purpose

Quick-reference material for Rails development.

These references are intended for lookup rather than learning. For in-depth explanations, see the referenced guides and handbooks.

Rails Conventions

Concept	Convention	Example
Model	Singular, CamelCase	UserAccount
Table	Plural, snake_case	user_accounts
Controller	Plural, CamelCase with Controller	UserAccountsController
Route	Resourceful, snake_case	resources :users
Migration	Descriptive snake_case	add_email_to_users
Service	Named after operation	RegisterUser

Common Generators

Command	Creates
rails generate model User email:string	Model, migration, factory
rails generate controller Api::V1::Users	Controller, routes, specs
rails generate migration add_email_to_users	Migration file
rails generate resource Product name:string	Model, controller, routes,
	migration, factory

Testing Commands

Command	Purpose
bundle exec rspec	Run full test suite.
bundle exec rspec spec*models*	Run model specs.
bundle exec rspec spec*requests*	Run request specs.
bundle exec rspec spec*system*	Run system specs.
bundle exec rspec spec*models*user_spec.rb:5	Run a single test by line.

Key Gems

Gem	Purpose
Devise	Authentication
Pundit	Authorization
RSpec-Rails	Testing framework
FactoryBot	Test data factories
Sidekiq	Background job processing
Bullet	N+1 query detection
RuboCop	Style linting
Rack::Attack	Rate limiting

Rails Error Codes

HTTP Code	Rails Helper	When to Use
200	:ok	Successful GET request.
201	:created	Successful POST (resource
		created).
204	:no_content	Successful DELETE or PUT with
		no response body.
400	:bad_request	Malformed request parameters.
401	:unauthorized	Authentication required.
403	:forbidden	Authenticated but not
		authorized.
404	:not_found	Resource does not exist.
422	:unprocessable_entity	Validation failure.
429	:too_many_requests	Rate limit exceeded.

Related Documents

• Rails Engineering Handbook
• Rails Glossary
• Service Objects Guide
• Testing Rails Applications Guide
• Architecture References