opal/opal

# frozen_string_literal: true

require 'opal/nodes/base'

module Opal
  module Nodes
    module Args
      # This node is responsible for extracting a single
      # splat keyword argument from $kwargs
      #
      # $kwargs always exist (as argument when inlining is possible
      # and as a local variable when it's not)
      #
      class ExtractKwrestarg < Base
        handle :extract_kwrestarg
        children :name

        def compile
          # def m(**)
          # arguments are assigned to `$kw_rest_arg` for super call
          name = self.name || '$kw_rest_arg'

          add_temp name

          helper :kwrestargs

          push "#{name} = $kwrestargs($kwargs, #{used_kwargs})"
        end

        def used_kwargs
          args = scope.used_kwargs.map do |arg_name|
            "'#{arg_name}': true"
          end

          "{#{args.join ','}}"
        end
      end
    end
  end
end