class RuboCop::Cop::Rails::PluckInWhere
This cop identifies places where `pluck` is used in `where` query methods and can be replaced with `select`.
Since `pluck` is an eager method and hits the database immediately, using `select` helps to avoid additional database queries.
This cop has two different enforcement modes. When the EnforcedStyle is conservative (the default) then only calls to `pluck` on a constant (i.e. a model class) in the `where` is used as offenses.
When the EnforcedStyle is aggressive then all calls to `pluck` in the `where` is used as offenses. This may lead to false positives as the cop cannot replace to `select` between calls to `pluck` on an `ActiveRecord::Relation` instance vs a call to `pluck` on an `Array` instance.
@example
# bad Post.where(user_id: User.active.pluck(:id)) # good Post.where(user_id: User.active.select(:id)) Post.where(user_id: active_users.select(:id))
@example EnforcedStyle: conservative (default)
# good Post.where(user_id: active_users.pluck(:id))
@example EnforcedStyle: aggressive
# bad Post.where(user_id: active_users.pluck(:id))
Constants
- MSG
- RESTRICT_ON_SEND
Public Instance Methods
# File lib/rubocop/cop/rails/pluck_in_where.rb, line 45 def on_send(node) return unless in_where?(node) return if style == :conservative && !root_receiver(node)&.const_type? range = node.loc.selector add_offense(range) do |corrector| corrector.replace(range, 'select') end end
Private Instance Methods
# File lib/rubocop/cop/rails/pluck_in_where.rb, line 58 def root_receiver(node) receiver = node.receiver if receiver&.send_type? root_receiver(receiver) else receiver end end