Functional Testing using Selenium and PhantomJS with Python

You may have a project requirement to improve performance of a test automation script within a short time period.It is not a good practice to go for a big code change at this kind of situation.To do that, one option is use headless browser instead of your ordinary web browser.Headless browser is a browser which doesn’t have GUI.When do headless browser testing we don’t see any GUI but program runs in background.because of that no need to wait until browser opens and load the web content to perform actions on web elements.Therefore you can save lot of test execution time.
PhantomJs is one of the widely used headless driver.This helps to run a bunch of test cases  without ever having to open a web browser.You can take screen shots of each step while test case is executing even though user doesn’t see the GUI


Following few steps explain you how to do functional testing using Selenium and PhantomJs with Pyhton.

• Open  Visual Studio IDE.
• Go to NuGet Packages and install PhantomJs.

• In windows add PhantomJs.exe location as environment  PATH variable.
• Create new python project and do coding.
• In following example  first create instance of phantomjs driver and moves to google search page,at this point take a screenshot of google search page(testimg1.png). Then verify “I’m Feeling Lucky” button available on the page. If the button available, click on the button.Another screen shot taken after button click step(testimg2.png). After that verify the page title of the new page that navigate after click on “I’m Feeling Lucky” button.

import unittest
from selenium import webdriver
from selenium.webdriver.support.wait import WebDriverWait
from selenium.webdriver.common.by import By
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.common.keys import Keys

class PythonApplication1(unittest.TestCase): 
    def test_case1(self):
        driver=webdriver.PhantomJS()        
        driver.get('https://www.google.lk/') 
        driver.save_screenshot("testimg1.png")
        wait=WebDriverWait(driver,60)
        feelingBtn=wait.until(EC.element_to_be_clickable((By.NAME,"btnI")))
        assert True,feelingBtn        
        feelingBtn.click()   
        driver.save_screenshot("testimg2.png")         
        self.assertEqual(True,wait.until(EC.title_contains("Google Doodles")))       
        driver.quit()

• Test script can be run by right click inside the test case method and select “Run Tests” or using test explorer.

• While you execute above test case you can find screenshots within project folder.These are the screen shots of above test case.

testimg1.png                                                                  testimg2.png

To check the performance improvement, I execute same test case on same windows machine with chrome,IE and PhantomJs.According to the following results you can see there is a performance improvement when use headless browser.

Browser Run time(average of 5 runs) Chrome 18.4 seconds IE 11.4 seconds PhantomJs 9.2 seconds