Rubocop configs linter.

lint_rubocop_config.rake

namespace :lint do
  task :rubocop_config do
    errors = []

    Dir[File.expand_path("../../../config/rubocop/*.yml", __dir__)].each do |f|
      config = Psych.parse_file(f)&.children&.first

      unless config.is_a? Psych::Nodes::Mapping
        errors << "Invalid config: #{f}"
        next
      end

      keys = config.children.grep(Psych::Nodes::Scalar).map(&:value)
      next if keys.sort == keys

      errors << "Invalid sort of keys: #{f}"
    end

    unless errors.empty?
      errors = errors.map { |e| "  - #{e}" }.join("\n")
      abort "Found invalid configs:\n\n#{errors}"
    end
  end
end