Specify an :inverse_of
option. Open
has_many :subscriptions, class_name: ScheduledReport, foreign_key: :report_id
- Read upRead up
- Exclude checks
This cop looks for has(one|many) and belongsto associations where
ActiveRecord can't automatically determine the inverse association
because of a scope or the options used. This can result in unnecessary
queries in some circumstances. :inverse_of
must be manually specified
for associations to work in both ways, or set to false
to opt-out.
Example:
# good
class Blog < ApplicationRecord
has_many :posts
end
class Post < ApplicationRecord
belongs_to :blog
end
Example:
# bad
class Blog < ApplicationRecord
has_many :posts, -> { order(published_at: :desc) }
end
class Post < ApplicationRecord
belongs_to :blog
end
# good
class Blog < ApplicationRecord
has_many(:posts,
-> { order(published_at: :desc) },
inverse_of: :blog
)
end
class Post < ApplicationRecord
belongs_to :blog
end
# good
class Blog < ApplicationRecord
with_options inverse_of: :blog do
has_many :posts, -> { order(published_at: :desc) }
end
end
class Post < ApplicationRecord
belongs_to :blog
end
Example:
# bad
class Picture < ApplicationRecord
belongs_to :imageable, polymorphic: true
end
class Employee < ApplicationRecord
has_many :pictures, as: :imageable
end
class Product < ApplicationRecord
has_many :pictures, as: :imageable
end
# good
class Picture < ApplicationRecord
belongs_to :imageable, polymorphic: true
end
class Employee < ApplicationRecord
has_many :pictures, as: :imageable, inverse_of: :imageable
end
class Product < ApplicationRecord
has_many :pictures, as: :imageable, inverse_of: :imageable
end
Example:
# bad
# However, RuboCop can not detect this pattern...
class Physician < ApplicationRecord
has_many :appointments
has_many :patients, through: :appointments
end
class Appointment < ApplicationRecord
belongs_to :physician
belongs_to :patient
end
class Patient < ApplicationRecord
has_many :appointments
has_many :physicians, through: :appointments
end
# good
class Physician < ApplicationRecord
has_many :appointments
has_many :patients, through: :appointments
end
class Appointment < ApplicationRecord
belongs_to :physician, inverse_of: :appointments
belongs_to :patient, inverse_of: :appointments
end
class Patient < ApplicationRecord
has_many :appointments
has_many :physicians, through: :appointments
end
@see http://guides.rubyonrails.org/association_basics.html#bi-directional-associations @see http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html#module-ActiveRecord::Associations::ClassMethods-label-Setting+Inverses
Specify a :dependent
option. Open
has_many :subscriptions, class_name: ScheduledReport, foreign_key: :report_id
- Read upRead up
- Exclude checks
This cop looks for has_many
or has_one
associations that don't
specify a :dependent
option.
It doesn't register an offense if :through
option was specified.
Example:
# bad
class User < ActiveRecord::Base
has_many :comments
has_one :avatar
end
# good
class User < ActiveRecord::Base
has_many :comments, dependent: :restrict_with_exception
has_one :avatar, dependent: :destroy
has_many :patients, through: :appointments
end
Models should subclass ApplicationRecord
. Open
class Report < ActiveRecord::Base
- Read upRead up
- Exclude checks
This cop checks that models subclass ApplicationRecord with Rails 5.0.
Example:
# good class Rails5Model < ApplicationRecord # ... end
# bad class Rails4Model < ActiveRecord::Base # ... end
Prefer to_s
over string interpolation. Open
"#{client_query}"
- Read upRead up
- Exclude checks
This cop checks for strings that are just an interpolated expression.
Example:
# bad
"#{@var}"
# good
@var.to_s
# good if @var is already a String
@var