Check image is displayed with selenium

You want to check if image is displayed with selenium but selenium API doesn’t really gives you any helpers to do that , so we can implement a small helper to check image is displayed with selenium.

We can actually check if the service returns the proper mime types in the Content-Type HTTP header. Here you can find a list with mime types.

To check the Content-Type header for image in ruby using Net::HTTP, you should use the following code:

 def image_exist?(url)
      url = URI.parse(url)
        http = Net::HTTP.new(url.host, url.port)
        http.use_ssl = (url.scheme == "https")
        http.start do |http|
          return http.head(url.request_uri)['Content-Type'].start_with? 'image'
       end
end

This piece of code will return true of false if the content type it’s an image so you can check it using mini test assertions :

# should be present
assert_true(image_exist?(url)

# should not be present
assert_false(image_exist?(url)

There are also alternatives using xpath to check :

assert_true(find(:xpath,"//header[@src='logo.png']").visible?)

Happy Testing!