Synvert::Rewriter.new "convert_rspec_its_to_it", "RSpec converts its to it" do
  gem_spec 'rspec', '2.99.0'

  [:should, :should_not].each do |message|
    within_files 'spec/**/*.rb' do
      # describe 'example' do
      #   subject { { foo: 1, bar: 2 } }
      #   its(:size) { should == 2 }
      #   its([:foo]) { should == 1 }
      #   its('keys.first') { should == :foo }
      # end
      # =>
      # describe 'example' do
      #   subject { { foo: 1, bar: 2 } }
      #
      #   describe '#size' do
      #     subject { super().size }
      #     it { should == 2 }
      #   end
      #
      #   describe '[:foo]' do
      #     subject { super()[:foo] }
      #     it { should == 1 }
      #   end
      #
      #   describe '#keys' do
      #     subject { super().keys }
      #     describe '#first' do
      #       subject { super().first }
      #       it { should == :foo }
      #     end
      #   end
      # end
      with_node type: 'block', caller: {message: 'its'} do
        if node.body.length == 1
          its_arg = node.caller.arguments.first.source(self)
          its_arg = its_arg[1...-1] if its_arg =~ /^['"].*['"]$/
          its_arg = its_arg[1..-1] if its_arg[0] == ':'
          rewritten_code = ""
          args = its_arg.split(".")
          args.each_with_index do |arg, index|
            describe_name = arg[0] =~ /^[a-z]/ ? '#' + arg : arg
            message_name = arg[0] =~ /^[a-z]/ ? '.' + arg : arg
            rewritten_code << "#{'  ' * index}describe '#{describe_name}' do\n"
            rewritten_code << "#{'  ' * (index + 1)}subject { super()#{message_name} }\n"
            rewritten_code << "#{'  ' * (index + 1)}it { {{body}} }\n" if index + 1 == args.length
          end
          args.length.times do |i|
            rewritten_code << "#{'  ' * (args.length - 1 - i)}end\n"
          end
          replace_with rewritten_code
        end
      end
    end
  end
end