def haml_file?(file)
      return false unless ::FileTest.file?(file)

      VALID_EXTENSIONS.include?(::File.extname(file))
    end
def haml_file?(file)
      return false unless ::FileTest.file?(file)

      VALID_EXTENSIONS.include?(::File.extname(file))
    end
Whether the given file should be treated as a Haml file.

 @param file [String]
 @return [Boolean]