WillPaginate customizes attributes of link_to (html a)

will_paginate.rb

#Add in your project in config/initializers/will_paginate.rb

#in my case I'm adding the attribute page_number with value of target

WillPaginate::ActionView::LinkRenderer.class_eval do
  def link(text, target, attributes = {})
    attributes.merge!(page_number: "#{target}")
    super text, target, attributes
  end
end

#please let me know if this helped someone