Regression Testing Basics

Tutorial 4 of 5

Regression Testing Basics

1. Introduction

1.1 Brief explanation of the tutorial's goal

This tutorial aims to provide a comprehensive introduction to the basics of Regression Testing. By the end of this tutorial, you should have a clear understanding of what Regression Testing is, why it's crucial, and how to implement it.

1.2 What the user will learn

The concept of Regression Testing
Steps to perform Regression Testing
Best practices for conducting Regression Testing
Practical coding examples of Regression Testing

1.3 Prerequisites

Basic understanding of Software Testing is beneficial but not required.

2. Step-by-Step Guide

2.1 Detailed explanation of concepts

Regression Testing is a type of software testing that verifies that previously developed and tested software still performs as expected after changes such as updates or patches. It helps to catch bugs that could be introduced when the codebase is modified.

2.2 Clear examples with comments

Let's assume that you have a module in your application that performs mathematical operations. You modify this module to add a new operation. Regression testing in this scenario would involve testing all the original operations to ensure they still work as expected.

2.3 Best practices and tips

Always keep the test cases up-to-date with software changes.
Automate regression tests where possible to save time.
Prioritize test cases based on the impact of the part of the application being changed.

3. Code Examples

This section provides examples of how regression testing might look in practice. Note that actual implementation would depend significantly on the specific software and testing framework used.

3.1 Code Snippet

# This is your original function
def add(a, b):
    return a + b

# Test case for original function
def test_add():
    assert add(2, 3) == 5

# You modify the function to subtract instead
def add(a, b):
    return a - b

# Regression test case
def test_add():
    assert add(2, 3) == -1

3.2 Explanation

In the example above, we first define an add function and a test case for it. Then we modify the add function to perform subtraction instead of addition. Finally, we update our test case to reflect the change in the function's behavior.

3.3 Expected Output

The expected output of the test case after modification should be True, indicating that the function is working as expected.

4. Summary

4.1 Key points covered

Understanding of Regression Testing
How to perform Regression Testing
Best practices in Regression Testing

4.2 Next steps for learning

To further your understanding of Regression Testing, consider learning about automated testing tools like Selenium, Junit, TestNG, etc.

4.3 Additional resources

5. Practice Exercises

5.1 Exercise 1

Write a function that calculates the factorial of a number. Write a test case for it. Then modify the function to return the square of the number instead. Update your test case to reflect this change.

5.2 Exercise 2

Write a function that sorts a list of numbers in ascending order. Write a test case for it. Then modify the function to sort the list in descending order. Update your test case to reflect this change.

5.3 Tips for further practice

Try to find more complex functions in your projects that you can modify and write regression tests for.