RSpec: compare rendered text like HTML or XML (use diffchecker.com for comparison of expected and got text if example fails)

example.html.erb_spec.rb

describe 'example.html.erb' do
  it 'renders HTML like this' do
    render
    
    compare_texts rendered, 'example.html'
  end
end

helper_methods.rb

def compare_texts(got_string, expected_fixture_path, preview = false)
  if preview
    absolute_path = File.join(File.dirname(__FILE__), "../fixtures/#{expected_fixture_path.split('/')[0..-2].join('/')}")
    FileUtils::mkdir_p absolute_path
    File.open("#{absolute_path}/#{expected_fixture_path.split('/')[-1]}", 'w') { |file| file.write(got_string) }
    puts "#{expected_fixture_path} created."
  else
    expect(strip_text(got_string)).to be == strip_text(load_fixture(expected_fixture_path))
  end
end

def load_fixture(path)
  path = File.join(File.dirname(__FILE__), "../fixtures/#{path}")
  File.open(path).read
end

def strip_text(text, remove_empty_lines = true)
  text = text.strip.split("\n").map(&:strip)
  
  text.delete_if{|line| line == '' } if remove_empty_lines
  
  text.join("")
end