An error occurred while Style/IfUnlessModifier cop was inspecting a <Rails model with a scope>

[goulvench]

My (working) Rails code seems to be causing the IfUnlessModifier cop to choke.

Actual behavior

$ rubocop --debug app/models/user.rb
An error occurred while Style/IfUnlessModifier cop was inspecting app/models/user.rb:28:60.
undefined method `last_argument' for #<RuboCop::AST::Node:0x00007f9fe625a890>
Did you mean?  last_line

/Users/goulven/.rbenv/versions/2.5.8/lib/ruby/gems/2.5.0/gems/rubocop-1.13.0/lib/rubocop/cop/style/if_unless_modifier.rb:71:in `autocorrect'
/Users/goulven/.rbenv/versions/2.5.8/lib/ruby/gems/2.5.0/gems/rubocop-1.13.0/lib/rubocop/cop/style/if_unless_modifier.rb:62:in `block in on_if'
/Users/goulven/.rbenv/versions/2.5.8/lib/ruby/gems/2.5.0/gems/rubocop-1.13.0/lib/rubocop/cop/base.rb:342:in `correct'
/Users/goulven/.rbenv/versions/2.5.8/lib/ruby/gems/2.5.0/gems/rubocop-1.13.0/lib/rubocop/cop/base.rb:127:in `add_offense'
/Users/goulven/.rbenv/versions/2.5.8/lib/ruby/gems/2.5.0/gems/rubocop-1.13.0/lib/rubocop/cop/style/if_unless_modifier.rb:61:in `on_if'

Steps to reproduce the problem

class User < ApplicationRecord
  scope :subscribed, -> { where(subscribed: true) }
  scope :unsubscribed, -> { where(subscribed: false) }
  scope :with_subscription_status, ->(subscription = nil) { (subscription == 'true' ? subscribed : unsubscribed) unless subscription.blank? }
end

RuboCop version

$ [bundle exec] rubocop -V
1.13.0 (using Parser 3.0.1.0, rubocop-ast 1.4.1, running on ruby 2.5.8 x86_64-darwin19)

[koic]

This issue is a dup with #9729 and resolved by #9730. Please update to the latest RuboCop 1.14. Thank you.