Unit Testing With Python

Unit Test Framework
Selenium is used for Web UI automation ,
To write and to maintain test cases a framework is required.
Here in this case  Unitest is used for this purpose

About Unittest

• Unittest module started life as the third-party module PyUnit.
• Unittest support fixtures,test suites and a test runner to enable automated testing.

Core Class of unittest

1. TestCase 
2. TestSuite
3. TestLoader
4. TextTestRunner
5. TestResults

TestCase

• TestCase is a one of the core classes of unittest module.
• TestCase has to be inherited from unittest module
• All the test routines or methods must start with "test".
•  Only then will they be executed, Test case can be in a different file,if so the module to be tested must be imported.

  #We need to import the unittest module import unittest #Testcase class TestLoginPage(unittest.TestCase): """We are testing the loginpage""" def test_case_1(self): print ("I am test case no 1") def test_case_2(self): print ("I am test example 2") def test_case_3(self): print ("I am test example 3") #To execute the unittest if __name__ == "__main__": unittest.main(exit=False) #Parameter for exit is set as False since this code is executed in IDLE

Example 1
#Save the below code in lowercasevowel.py def count_lower_case_vowels(s): """(str) -> number Return the number of lower case vowels found in the input string s """ no_of_vowels = 0 for vowels in s: if vowels in "aeiou": no_of_vowels +=1 return no_of_vowels

Unit test for lowercasevowel.py #Save the below code in unit_for_lowercasevowel.py #import the required modules import lowercasevowel import unittest #Testcase class TestingLowerCaseVowels(unittest.TestCase): """We are testing the lowercasevowel.py""" def test_case_1(self): actual = lowercasevowel.count_lower_case_vowels("b") expected = 0 self.assertEqual(actual,expected) def test_case_2(self): actual = lowercasevowel.count_lower_case_vowels("aeiou") expected = 5 self.assertEqual(actual,expected) def test_case_3(self): actual = lowercasevowel.count_lower_case_vowels("jude") expected = 2 self.assertEqual(actual,expected) #To execute the unittest if __name__ == "__main__": unittest.main(exit=False) #Parameter for exit is set as False since this code is executed in IDLE


Output

>>> ... ---------------------------------------------------------------------- Ran 3 tests in 0.047s OK >>>
Note: each "." represents testcase successfully executed ,if test case fails "F" instead of "."
F ====================================================================== FAIL: test_google_search (__main__.GoogleSearch) ---------------------------------------------------------------------- Traceback (most recent call last): File "D:\coursera\selenium\google.py", line 21, in test_google_search self.assertIn(self.browser.title,"Go") AssertionError: 'Google' not found in 'Go' ---------------------------------------------------------------------- Ran 1 test in 28.112s FAILED (failures=1) >>>

Structure of TestCase Class of unittest 

1. setUp() where pre-condition for executing the test case are written down.
2. tearDown() here clean up ,which is required after each test case is written down.
3. skipTest() will skip the current test.
4. fail() will fail the test explicitly ie..It will fail the test an raise AssertionError.
5. id() Return a string containing the name of the TestCase object and of the test method.
6. shortDescription() Return the Docstring present in the Test case method.

Note:setUp() get executed before all the test_case() method and tearDown() after each test_case()
methods.

Example 2
 Let us use the setUp() and tearDown() methods

#General test case Template #imports import unittest from selenium import webdriver #Test case class class GeneralTemplate(unittest.TestCase): def setUp(self): """Here we create browser object and access a url if needed""" print("I am setUp") def tearDown(self): """Here we close the browser ie..clean up process after the test case """ print("I am Tear down") def test_caseNo1(self): """Here the code is written for the testing the Web UI """ print("I am test case no1")


Example 3
 Let us use the setUp() and tearDown() id() & shortDescription() methods


import unittest class LearningUnittest(unittest.TestCase): def setUp(self): testName = self.shortDescription() if testName == "test case 1": print("start of test case 1") elif testName == "test case 2": print("start of test case 2") elif testName == "test case 3": print("start of test case 3") else: print("unknown test case starting") def tearDown(self): testName = self.shortDescription() if testName == "test case 1": print("stop of test case 1") elif testName == "test case 2": print("stop of test case 2") elif testName == "test case 3": print("start of test case 3") else: print("unknown test case stop") def test_case_1(self): """test case 1""" print("hello here i am 1") def test_case_2(self): """test case 2""" print("hello here i am 2") def test_case_3(self): """test case 3 """ self.fail("test case 3 fail") if __name__ == "__main__": unittest.main()

Problem 1
Search for a python tutorial on youtube ?

Answer

1. Open a browser (firefox)
#we need to create webdriver object #To do that we need to import webdriver from selenium from selenium import webdriver #Now we create a webdriver browser = webdriver.Firefox()
2. Nagivate to "http://www.youtube.com"
#To nagivate any web-page in the browser we can use the get command browser.get("http://www.youtube.com")
3. Verify that youtube page is opened
#we use assert if the assert fails #The execution will stop at the assert point in the test case #An AssertionError is raised, but the tearDown method is always called. assertIn("YouTube",browser.title)
4. Locate the search Box and type in Python Tutorials
#Let us locate search box using id #Using Firebug we can inspect the search box's id searchElement = browser.find_element_by_id("masthead-search-term") #Let us enter "python tutorials" searchElement.send_keys("python tutorials") #Press the enter key searchElement.send_keys(Keys.RETURN)
5. To take a screenshot
browser.screenshot('YoutubeSearch.png') #The screenshot is stored as YoutubeSearch.png #In the same directory as youtube.py

The complete solution with unittest as Framework

 #Save the below code in youtube.py import unittest from selenium import webdriver from selenium.webdriver.common.keys import Keys class YoutubeSearch(unittest.TestCase): def setUp(self): print("-----Starting setup------") self.browser = webdriver.Firefox() self.browser.get("http://www.youtube.com") print("-----setup complete-----") def tearDown(self): print("-----starting teardown------") self.browser.screenshot('YouTubeSearch.png') self.browser.quit() print("----teardown complete-------") def test_youtube_search(self): print("-----in the test------") self.assertIn("YouTube",self.browser.title) searchElement = self.browser.find_element_by_id("masthead-search-term") searchElement.send_keys("python tutorials") searchElement.send_keys(Keys.RETURN) print("----test case complete----") if __name__ == "__main__": unittest.main(exit=False,warnings = 'ignore') #Parameter for exit is set as False since this code is executed in IDLE


Output

================================ RESTART ================================ >>> -----Starting setup------ -----setup complete----- -----in the test------ ----test case complete---- -----starting teardown------ ----teardown complete------- . ---------------------------------------------------------------------- Ran 1 test in 46.460s OK >>>