Rspec :have_tag matcher

RSpecHtmlMatcher.rb

require 'rspec/expectations'

RSpec::Matchers.define :have_tag do |html_tag|
  match do |html_string|
    @doc = Nokogiri::HTML.fragment(html_string)
    @html_tag = html_tag

    if @class_names.nil? && @content.nil?
      have_html_tag?(html_tag)
    elsif @class_names && @content.nil?
      have_html_tag?(html_tag) && have_class_name?(html_tag)
    elsif @content
      have_html_tag?(html_tag) && have_content?(html_tag)
    end
  end

  chain :with_class do |class_names|
    @class_names = class_names
  end

  chain :with_content do |content|
    @content = content
  end

  def have_html_tag?(html_tag)
    @doc.search(html_tag).any?
  end

  def have_class_name?(html_tag)
    doc_class_names = @doc.at(html_tag).attributes['class'].value.split(' ').sort
    doc_class_names.include?(@class_names) || doc_class_names == @class_names.split(' ').sort
  end

  def have_content?(html_tag)
    @doc.at(html_tag).text.strip == @content.strip
  end
end

RSpec.describe "<p class='style fa'>Teste</p>" do
  it { is_expected.to have_tag('p') } # should pass
  it { is_expected.to_not have_tag('a') } # should pass
  it { is_expected.to have_tag('p').with_class('style') } # should pass
  it { is_expected.to have_tag('p').with_class('fa stas')} # should fail
  it { is_expected.to have_tag('p').with_content('Teste') } # should pass
  it { is_expected.to have_tag('p').with_content('Teste1') } # should fail
end


RSpec::Matchers.define :have_class_name_at do |class_name, html_tag|
  match do |html_string|
    doc = Nokogiri::HTML.fragment(html_string)
    class_names = doc.at(html_tag).attributes['class'].value.split(' ')
    class_names.include?(class_name)
  end
end

RSpec::Matchers.define :have_content_at do |content, html_tag|
  match do |html_string|
    doc = Nokogiri::HTML.fragment(html_string)
      doc.at(html_tag).text.strip == content.strip
  end
end