A Complete Guide to Regression Testing
Tags: regression, testing
Published: 2023-08-17 14:45:52

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As a software developer, you know that testing is essential to the development process. One type of testing that’s particularly important is regression tests. In this guide, we’ll walk you through everything you need about regression testing, including what it is, why it’s important, and how to develop a comprehensive strategy.

**What is Regression Testing**?

Regression testing involves testing a software system to ensure that upgrades or changes to the system have not resulted in any new flaws or problems. This is crucial because even little modifications to software systems may have unforeseen effects that lead to bugs or other problems.

**The Importance of Regression Testing**

Regression analysis holds significant importance for multiple reasons. It mostly aids in ensuring that the software system keeps working properly after changes have been made. This is crucial because even little modifications to software systems may have unforeseen effects that lead to bugs or other problems.

Regression testing helps lower the chance of introducing new bugs or issues into the system and assuring that the software system continues to operate appropriately. After changes have been made, tests should be done to identify any potential issues before they become significant difficulties.

**The Regression Testing Process**
Regression testing often involves several steps. The specific software system being tested dictates the variability of these steps; however, in general, they consists of the following:

**Step 1: Identify the Test Cases**
Finding the test cases that will be used to test the software system is the first stage in the regression testing process. These test cases cover every software system feature and are built to catch any potential problems in advance.

**Step 2: Automate the Test Cases**
Once the test cases have been identified, the next step is to automate them. This involves writing scripts that can be used to run the tests automatically. Automation is important because it allows the tests to be run quickly and easily every time a change is made to the software system.

**Step 3: Run the Test Cases**
Running the test cases is the next step. This involves executing the automated scripts and verifying that the software system functions correctly. In case any problems arise during the testing process, they ought to be recorded and dealt with.

**Step 4: Analyse the Results**
The outcomes of the test cases should be examined after they have been run. This involves reviewing the logs to identify any issues during the testing process. If any issues were identified, they should be addressed before moving on to the next step.

**Step 5: Repeat the Process**
Finally, the regression testing process should be repeated every time a change is made to the software system. This helps ensure that the system continues functioning correctly and that new bugs or issues are not introduced.

**When Should Regression Testing be performed**?

Regression testing should ideally be conducted regularly throughout the software development and maintenance process. Some specific scenarios that warrant regression testing include:

**Addition of new features**: When new functionality is added to the software, regression testing can help identify any issues or conflicts with existing features, ensuring a seamless integration of the new feature.

**Updates to existing features**: Changes or updates to existing features can potentially impact the software’s overall functionality. Regression testing can help verify that these updates have no adverse impact on the system.

**Bug fixes**: When bugs are fixed, there is a possibility that the fix might introduce new issues or affect other parts of the software. Regression testing helps ensure that the bug fix does not adversely impact the system’s functionality.

**Types of Regression Testing**

There are several types of regression testing, each designed to address specific aspects of the software maintenance process. Here, we will discuss seven common types of regression testing:

1. **Corrective Regression Testing**

This type of regression testing is employed when there are no changes to the software’s specifications and the existing test cases can be reused. Corrective regression testing focuses on verifying that the software continues to function as expected after bug fixes or minor updates.

2. **Retest-All Regression Testing**

Retest-all regression testing involves re-running all the test cases for the software, regardless of whether they were directly affected by the changes made during maintenance. This approach is typically used when other types of regression testing have failed to identify issues, or when there is a high degree of uncertainty about the potential impact of the changes.

3. **Selected Regression Testing**

Selected regression testing involves re-running a subset of the original test cases, specifically targeting the areas of the software that were affected by the changes made during maintenance. This approach can help reduce the time and effort required for regression testing by focusing on the areas most likely to be impacted by the updates.

4. **Progressive Regression Testing**

Progressive regression testing involves creating new test cases specifically for the changes made to the software during maintenance. This approach can provide more detailed information about the impact of the updates and help ensure that no issues were introduced during the maintenance process.

5. **Complete Regression Testing**

Complete regression testing is applied when the software has undergone significant updates or changes. These types of testing aims to identify any issues that may have gone unnoticed during the development process and ensure that the final product is free from bugs and defects.

6. **Partial Regression Testing**

Partial regression testing is performed to verify the impact of new code additions on the existing functionality of the software. By focusing on the areas affected by the new code, partial regression testing helps ensure that the system continues to function as intended after the updates.

7. **Unit Regression Testing**

Unit regression testing is a focused form of regression testing that targets specific code units, such as functions or methods. This type of testing is typically conducted independently, without any dependencies or interactions with other parts of the software, to help identify issues at the individual code unit level.

**Conclusion**

Test automation software is an essential part of the software development process. Opkey is an excellent example of test automation software that can be used as a part of the software development process. By following the steps outlined in this guide and utilising Opkey’s advanced features for regression testing. You can develop a comprehensive testing strategy that will help ensure that your software system functions correctly and that new bugs or issues are not introduced.