class Capybara::Selector::XPathBuilder

def attribute_conditions(attributes)
  attributes.map do |attribute, value|
    case value
    when XPath::Expression
      XPath.attr(attribute)[value]
    when Regexp
      XPath.attr(attribute)[regexp_to_xpath_conditions(value)]
    when true
      XPath.attr(attribute)
    when false, nil
      !XPath.attr(attribute)
    else
      XPath.attr(attribute) == value.to_s
    end
  end.reduce(:&)
end

def class_conditions(classes)
  case classes
  when XPath::Expression
    XPath.attr(:class)[classes]
  when Regexp
    XPath.attr(:class)[regexp_to_xpath_conditions(classes)]
  else
    Array(classes).map do |klass|
      if klass.start_with?('!')
        !XPath.attr(:class).contains_word(klass.slice(1..-1))
      else
        XPath.attr(:class).contains_word(klass)
      end
    end.reduce(:&)
  end
end

def regexp_to_xpath_conditions(regexp)
  condition = XPath.current
  condition = condition.uppercase if regexp.casefold?
  Selector::RegexpDisassembler.new(regexp).substrings.map do |str|
    condition.contains(str)
  end.reduce(:&)
end