refinement builder class

refinement_builder.rb

module CoreExt; end

module CoreExt::RefinementBuilder

  def build_refinement(class_name, namespace: Object, refines: Object, &blk)
    const = namespace.const_set class_name, Module.new(&blk)
    const.instance_methods(false).each do |method_name|
      orig_method = const.instance_method method_name
      const.send :define_method, method_name do |*args, **keywords, &blk|
        if eql?(const)
          if keywords.empty?
            orig_method.bind(const).call *args, &blk
          else
            orig_method.bind(const).call *args, **keywords, &blk
          end
        else
          if keywords.empty?
            const.send method_name, *args, &blk
          else
            const.send method_name, *args, **keywords, &blk
          end
        end
      end
      const.send :module_function, method_name
      const.send(:refine, refines) { include const }
    end
  end

  module_function :build_refinement

  refine Object do
    include CoreExt::RefinementBuilder
  end

end

usage.rb

using CoreExt::RefinementBuilder

build_refinement "Util" do

  def a
    1
  end

  def b
    a
  end

end

# The above definitiomn enables all the following usages:

# 1. Use the methods as a refinement
#    By default they are patched onto Object but this can be changed
#    by supplying a refines: <class> option to build_refinement.
class Foo
  using Util
  puts b # => 1
  puts a => 1
end

# 2. Use the methods statically
puts Util.a # => 1
puts Util.b # => 2

# 3. Use as a typical module via include
include Util
puts b # => 1
puts a # => 1