Unittest is a popular testing framework in Python that allows developers to write test cases for their code. It provides a set of tools and assertions to validate the correctness of the code’s behavior.

리그레션 테스팅이란 개발 중인 소프트웨어에 수정이 가해질 때, 변경 내용이 기존의 기능에 영향을 주는지 확인하는 것을 말합니다. 이전에 제대로 작동하던 기능이 수정 사항으로 인해 오작동하는 경우, 리그레션 테스팅을 통해 이를 감지하고 조치할 수 있습니다.

이번 블로그 포스트에서는 Unittest를 사용하여 자동화된 리그레션 테스트를 구현하는 방법에 대해 알아보겠습니다.

Installing Unittest

Unittest is built-in with Python, so you don’t need to install any additional packages. You can start writing and running unit tests right away.

Writing Test Cases

To write test cases using Unittest, you need to create a test class and define individual test methods inside that class. Each test method should start with the name “test_”. This naming convention allows Unittest to identify the methods to be run as tests.

Here’s an example of a test class with two test methods:

import unittest

class MyTestCase(unittest.TestCase):
    def test_addition(self):
        result = 2 + 2
        self.assertEqual(result, 4, "Addition failed")

    def test_subtraction(self):
        result = 5 - 3
        self.assertEqual(result, 2, "Subtraction failed")

if __name__ == '__main__':
    unittest.main()

In the above example, we have a MyTestCase class that inherits from unittest.TestCase. It contains two test methods: test_addition() and test_subtraction(). In each test method, we perform a calculation and use the assertEqual() method to validate the result.

Running Test Cases

To run the test cases, we execute the test file. This can be done by running the Python script directly or using a test runner command like python -m unittest test_file.py. The test runner will discover all test cases and execute them.

When the tests run, Unittest will display the results on the console. It will indicate whether each test passed or failed, along with any error messages or traceback information.

Automating Regression Testing

To automate regression testing using Unittest, you can create test suites that contain multiple test cases. A test suite allows you to group related tests together and run them as a single entity.

Here’s an example of a test suite with multiple test cases:

import unittest
from my_module import MyTestCase

if __name__ == '__main__':
    suite = unittest.TestLoader().loadTestsFromTestCase(MyTestCase)
    unittest.TextTestRunner().run(suite)

In the above example, we import the MyTestCase class from the my_module module and load it into a test suite using TestLoader(). We then run the test suite using TextTestRunner(). This will execute all the test cases inside the MyTestCase class.

By automating the regression testing process with Unittest, you can easily verify that your code continues to function correctly even after modifications or updates.

Conclusion

Unittest is a powerful testing framework in Python that enables developers to automate regression testing. By writing test cases and running them using Unittest, you can verify the correctness of your code and ensure that changes and updates do not introduce new bugs or issues.

Automating regression testing with Unittest helps in maintaining code quality, improving stability, and catching issues early in the development cycle.

I hope this blog post has provided you with an overview of using Unittest for automated regression testing in Python. Happy testing!