Evaluation with selector

gistfile1.rb

def evaluate_css(property, selector = 'body')
  page.evaluate_script("(typeof jQuery !== 'undefined') && $('#{selector}').css('#{property}')")
end

def expect_css(property, values)
  values.each do |selector, value|
    begin
      wait_until { evaluate_css(property, selector) == value}
    rescue Capybara::TimeoutError
      evaluate_css(property, selector).should == value
    end
  end
end

Won't work. You want to have

expect_css "body", "color" => "#fff"

So you need to do

def expect_css(selector, styles)
  styles.each do |property, expected_value|
    begin
      wait_until { evaluate_css(selector, property) == expected_value }
    rescue Capybara::TimeoutError
      evaluate_css(selector, property).should == expected_value
  end
end

You are calling evaluate_css(selector, property) inverted?