AttributeError: 'WebElement' object has no attribute 'get_screenshot'

[mzbedat]

Hi,
I started looking into needle (instead of ApliTools) and trying to create a test but facing an issue with this command:
element.get_screenshot().save(baseline_file)
In compareScreenshot() method cases.py file

File "C:\Python27\lib\site-packages\needle\cases.py", line 238, in compareScreenshot
element.get_screenshot().save(output_file)
AttributeError: 'WebElement' object has no attribute 'get_screenshot'

My guess that the driver that am referring to is the selenium web driver, but the one used in cases.py is the needle driver!

My code:

from needle.cases import NeedleTestCase

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

from time import sleep

class NebulaTest(NeedleTestCase):
def init(self):
self.output_directory = "C:\screenshots"
self.baseline_directory = "C:\screenshots\baseline"
#self.engine_class = 'needle.engines.perceptualdiff_engine.Engine'
#engine_class = 'needle.engines.imagemagick_engine.Engine'

    self.driver = webdriver.Chrome()
    self.test_feedback()
    
def test_feedback(self):
    
    #self.set_viewport_size(width=1024, height=768)
    
    self.driver.get('https://kampyle25.tumblr.com/')
    
    sleep(5)
    #try:
    #    WebDriverWait(self.driver, 10).until(EC.presence_of_element_located((By.CSS_SELECTOR, "div.kampyle_button-text")))
    #finally:
    #    self.driver.quit()
    
    self.assertScreenshot('div.kampyle_button-text', 'feedback')

NebulaTest()

Thanks in advance.

[mzbedat]

I switched to Needle Driver:
self.driver = self.get_web_driver()

But now I'm getting:

File "C:\Python27\lib\site-packages\needle\cases.py", line 241, in compareScreenshot
self.engine.assertSameFiles(output_file, baseline_file, threshold)
AttributeError: 'NebulaTest' object has no attribute 'engine'

This command line:
self.engine.assertSameFiles(output_file, baseline_file, threshold)

From this link I can see that I need to download and install PerceptualDiff:
http://the-creative-tester.github.io/Python-Visual-Regression-Testing/

that's require:

1. CMake (https://cmake.org/download/)
2. FreeImage (https://sourceforge.net/projects/freeimage/?source=typ_redirect)

But these aren't regular installations, the FreeImage for example is a dll... I have a feeling that am going in a wrong direction.
Can you please give more insights on it

[mzbedat]

calling from my Test class:
self.setUpClass()
did the trick.

I still have one question regarding saving the base-line image....
by running: nosetests Needle.py --with-save-baseline I'm getting

c:\workspace_medalia\robotautomation\Galil-RF\RobotFramework\Libraries\VisualTesting>nosetests Needle.py --with-save-baseline
E
======================================================================
ERROR: Failure: IOError (The baseline screenshot C:\VisualTesting\screenshots\baseline\feedback.png does not exist. You might want to re-run this test in baseline-saving mode.)

---

I order to come over it, I had overridden the save_base_line in my test class:
self.save_baseline = True

Isn't there an option to pass it as parameter? the --with-save-baseline was suppose to deal with it, no?!

[jeremyqa]

I had a similar problem at first but I believe I figured out what I was doing wrong. You need to use the driver object that has the NeedleWebDriverMixin. You're using regular chrome when you do

self.driver = webdriver.Chrome()

To do use the one with the Needle mixin, I overrode get_web_driver.

from needle.cases import NeedleTestCase
from needle.driver import NeedleChrome


class ExampleTest(NeedleTestCase):
    @classmethod
    def get_web_driver(cls):
        return NeedleChrome()


    def test_example(self):
        self.driver.get('http://example.com')
        self.assertScreenshot('body', 'example-body')

That came mostly from https://needle.readthedocs.io/en/latest/#selecting-a-webdriver