Gem::Commands::ContentsCommand#files_in_default_gem

# File tmp/rubies/ruby-4.0.0/lib/rubygems/commands/contents_command.rb, line 104
def files_in_default_gem(spec)
  spec.files.filter_map do |file|
    if file.start_with?("#{spec.bindir}/")
      [RbConfig::CONFIG["bindir"], file.delete_prefix("#{spec.bindir}/")]
    else
      gem spec.name, spec.version

      require_path = spec.require_paths.find do |path|
        file.start_with?("#{path}/")
      end

      requirable_part = file.delete_prefix("#{require_path}/")

      resolve = $LOAD_PATH.resolve_feature_path(requirable_part)&.last
      next unless resolve

      [resolve.delete_suffix(requirable_part), requirable_part]
    end
  end
end