Specify an :inverse_of
option. Open
has_many :observations, -> { where(observations: {type: 'Observation::Continuous'}) }, foreign_key: :descriptor_id
- Read upRead up
- Exclude checks
This cop looks for has(one|many) and belongsto associations where
Active Record can't automatically determine the inverse association
because of a scope or the options used. Using the blog with order scope
example below, traversing the a Blog's association in both directions
with blog.posts.first.blog
would cause the blog
to be loaded from
the database twice.
:inverse_of
must be manually specified for Active Record to use the
associated object in memory, or set to false
to opt-out. Note that
setting nil
does not stop Active Record from trying to determine the
inverse automatically, and is not considered a valid value for this.
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
# good
# When you don't want to use the inverse association.
class Blog < ApplicationRecord
has_many(:posts,
-> { order(published_at: :desc) },
inverse_of: false)
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 https://guides.rubyonrails.org/association_basics.html#bi-directional-associations @see https://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html#module-ActiveRecord::Associations::ClassMethods-label-Setting+Inverses
Prefer single-quoted strings when you don't need string interpolation or special symbols. Open
message: "%{value} is not a valid unit" }, allow_nil: true
- Read upRead up
- Exclude checks
Checks if uses of quotes match the configured preference.
Example: EnforcedStyle: single_quotes (default)
# bad
"No special symbols"
"No string interpolation"
"Just text"
# good
'No special symbols'
'No string interpolation'
'Just text'
"Wait! What's #{this}!"
Example: EnforcedStyle: double_quotes
# bad
'Just some text'
'No special chars or interpolation'
# good
"Just some text"
"No special chars or interpolation"
"Every string in #{project} uses double_quotes"