# File lib/sprockets/utils.rb, line 11
      def self.read_unicode(pathname, external_encoding = Encoding.default_external)
        pathname.open("r:#{external_encoding}") do |f|
          f.read.tap do |data|
            # Eager validate the file's encoding. In most cases we
            # expect it to be UTF-8 unless `default_external` is set to
            # something else. An error is usually raised if the file is
            # saved as UTF-16 when we expected UTF-8.
            if !data.valid_encoding?
              raise EncodingError, "#{pathname} has a invalid " +
                "#{data.encoding} byte sequence"

            # If the file is UTF-8 and theres a BOM, strip it for safe concatenation.
            elsif data.encoding.name == "UTF-8" && data =~ UTF8_BOM_PATTERN
              data.sub!(UTF8_BOM_PATTERN, "")
            end
          end
        end
      end