validate

# File lib/rubygems/specification.rb, line 2680
  def validate packaging = true
    @warnings = 0
    require 'rubygems/user_interaction'
    extend Gem::UserInteraction
    normalize

    nil_attributes = self.class.non_nil_attributes.find_all do |attrname|
      instance_variable_get("@#{attrname}").nil?
    end

    unless nil_attributes.empty? then
      raise Gem::InvalidSpecificationException,
        "#{nil_attributes.join ', '} must not be nil"
    end

    if packaging and rubygems_version != Gem::VERSION then
      raise Gem::InvalidSpecificationException,
            "expected RubyGems version #{Gem::VERSION}, was #{rubygems_version}"
    end

    @@required_attributes.each do |symbol|
      unless self.send symbol then
        raise Gem::InvalidSpecificationException,
              "missing value for attribute #{symbol}"
      end
    end

    if !name.is_a?(String) then
      raise Gem::InvalidSpecificationException,
            "invalid value for attribute name: \"#{name.inspect}\" must be a string"
    elsif name !~ /[a-zA-Z]/ then
      raise Gem::InvalidSpecificationException,
            "invalid value for attribute name: #{name.dump} must include at least one letter"
    elsif name !~ VALID_NAME_PATTERN then
      raise Gem::InvalidSpecificationException,
            "invalid value for attribute name: #{name.dump} can only include letters, numbers, dashes, and underscores"
    end

    if raw_require_paths.empty? then
      raise Gem::InvalidSpecificationException,
            'specification must have at least one require_path'
    end

    @files.delete_if            { |x| File.directory?(x) && !File.symlink?(x) }
    @test_files.delete_if       { |x| File.directory?(x) && !File.symlink?(x) }
    @executables.delete_if      { |x| File.directory?(File.join(@bindir, x)) }
    @extra_rdoc_files.delete_if { |x| File.directory?(x) && !File.symlink?(x) }
    @extensions.delete_if       { |x| File.directory?(x) && !File.symlink?(x) }

    non_files = files.reject { |x| File.file?(x) || File.symlink?(x) }

    unless not packaging or non_files.empty? then
      raise Gem::InvalidSpecificationException,
            "[\"#{non_files.join "\", \""}\"] are not files"
    end

    if files.include? file_name then
      raise Gem::InvalidSpecificationException,
            "#{full_name} contains itself (#{file_name}), check your files list"
    end

    unless specification_version.is_a?(Integer)
      raise Gem::InvalidSpecificationException,
            'specification_version must be an Integer (did you mean version?)'
    end

    case platform
    when Gem::Platform, Gem::Platform::RUBY then # ok
    else
      raise Gem::InvalidSpecificationException,
            "invalid platform #{platform.inspect}, see Gem::Platform"
    end

    self.class.array_attributes.each do |field|
      val = self.send field
      klass = case field
              when :dependencies
                Gem::Dependency
              else
                String
              end

      unless Array === val and val.all? { |x| x.kind_of?(klass) } then
        raise(Gem::InvalidSpecificationException,
              "#{field} must be an Array of #{klass}")
      end
    end

    [:authors].each do |field|
      val = self.send field
      raise Gem::InvalidSpecificationException, "#{field} may not be empty" if
        val.empty?
    end

    unless Hash === metadata
      raise Gem::InvalidSpecificationException,
              'metadata must be a hash'
    end

    validate_metadata

    licenses.each { |license|
      if license.length > 64
        raise Gem::InvalidSpecificationException,
          "each license must be 64 characters or less"
      end

      if !Gem::Licenses.match?(license)
        suggestions = Gem::Licenses.suggestions(license)
        message = license value '#{license}' is invalid.  Use a license identifier fromhttp://spdx.org/licenses or '#{Gem::Licenses::NONSTANDARD}' for a nonstandard license.
        message += "Did you mean #{suggestions.map { |s| "'#{s}'"}.join(', ')}?\n" unless suggestions.nil?
        warning(message)
      end
    }

    warning licenses is empty, but is recommended.  Use a license identifier fromhttp://spdx.org/licenses or '#{Gem::Licenses::NONSTANDARD}' for a nonstandard license. if licenses.empty?

    validate_permissions

    # reject lazy developers:

    lazy = '"FIxxxXME" or "TOxxxDO"'.gsub(/xxx/, '')

    unless authors.grep(/FI XME|TO DO/).empty? then
      raise Gem::InvalidSpecificationException, "#{lazy} is not an author"
    end

    unless Array(email).grep(/FI XME|TO DO/).empty? then
      raise Gem::InvalidSpecificationException, "#{lazy} is not an email"
    end

    if description =~ /FI XME|TO DO/ then
      raise Gem::InvalidSpecificationException, "#{lazy} is not a description"
    end

    if summary =~ /FI XME|TO DO/ then
      raise Gem::InvalidSpecificationException, "#{lazy} is not a summary"
    end

    # Make sure a homepage is valid HTTP/HTTPS URI
    if homepage and not homepage.empty?
      begin
        homepage_uri = URI.parse(homepage)
        unless [URI::HTTP, URI::HTTPS].member? homepage_uri.class
          raise Gem::InvalidSpecificationException, "\"#{homepage}\" is not a valid HTTP URI"
        end
      rescue URI::InvalidURIError
        raise Gem::InvalidSpecificationException, "\"#{homepage}\" is not a valid HTTP URI"
      end
    end

    # Warnings

    ]author homepage summary files].each do |attribute|
      value = self.send attribute
      warning "no #{attribute} specified" if value.nil? or value.empty?
    end

    if description == summary then
      warning 'description and summary are identical'
    end

    # TODO: raise at some given date
    warning "deprecated autorequire specified" if autorequire

    executables.each do |executable|
      executable_path = File.join(bindir, executable)
      shebang = File.read(executable_path, 2) == '#!'

      warning "#{executable_path} is missing #! line" unless shebang
    end

    files.each do |file|
      next unless File.symlink?(file)
      warning "#{file} is a symlink, which is not supported on all platforms"
    end

    validate_dependencies

    true
  ensure
    if $! or @warnings > 0 then
      alert_warning "See http://guides.rubygems.org/specification-reference/ for help"
    end
  end