Learn About Regression Testing Types & Methods to Execute Test Cases

Every year thousands of updates are released in the market. We keep hearing news about breaches in private data, surveillance or disruptions because of common bugs in applications that are released into the market. Even after thorough testing, such instances keep happening that hugely impact the safety of the users of an application making their data vulnerable to malicious attackers.

Imagine you are building a house. You cannot close up the walls with sheetrock or plaster until the building inspector had signed off on the electrical and plumbing work and provides you with a certificate. Now imagine after the complete layering for your apartment walls you suddenly realise one of your walls are chipping off from moisture. Here you will need to tear the walls open to fix the issue. The earlier you would have identified it the easier it would have been to fix it. The biggest issue with bugs found ages after the product has been released into the market is that it needs to be backdated and fixed such that it fits back into the system exactly like it was. More like fixing, plastering and painting the walls of your apartment as if nothing happened. That is where regression testing services come into the picture.

What is Regression Testing?

Regression testing is a black-box testing technique used to determine if the application or software is crash resistant and fully functional after the minutest changes in your code. The ideal way to proceed is by re-executing a set of test cases. Software testing professionals check the functionality of the entire system in which the minutest feature has been modified to ensure that these modifications do not impact the functionality of your system. There could be various alterations to an application be it new functionality enhancements, interfaces, patches, etc. Many development engineers insist that as long as essential functions are tested and can deliver results as per requirements, it would be sufficient, hence proving the requirement for initial software testing. On the other hand, some professionals argue that regression testing can prove more beneficial at the later stages because instead of just testing the basic functionality, it ensures thorough testing to avoid any leakages in the end.

Even the most irrelevant modifications in an application can end up in a complete functionality breakdown. Software testing companies use automated test suits that help cut down on testing cost and the amount of time required for regression testing. This allows them to maintain higher precision, and reducing human errors as well as run uninterrupted testing 24/7.

Applications of Regression Testing

Below mentioned are some of the basic applications of regression testing and its uses throughout the application testing life cycle:

Bug Regression: Check if the bug has been merely fixed or eliminated.
General Functional Regression: To check for code destabilisation on all areas of the app
Conversion and Port Testing: To check if that application has been successfully ported
Localisation Testing service: To check the performance of an interface and if the application follow new cultural norms.
Build Verification Testing: A series of small testing processes to verify if the build is worth fixing or not. In case the test fails, that build would be straight away rejected.

What are the Different Types of Regression Tests?

Below mentioned are the various types of regression tests:

1. Corrective Regression Testing

Conducted on existing test cases that involve minimum to zero code changes. It’s repetitive and takes comparatively less time in detecting bugs.

2. Progressive Regression Testing

Mostly done after the product had undergone few changes. While developing new test scenarios progressive testing allows you to test the updated functionalities without having to touch your basic code.

3. Retest All Regression Testing

These tests are conducted to identify any bugs in the entire system even when the code changes have been made in certain parts of the code only. Therefore, it’s one of the most time-consuming processes of all.

4. Selective Regression Testing

In this only selected test cases with changes from a module are processed. You can save a lot of time from running an entire test case with this. Other benefits of selective regression testing include:

Ability to analyse the outcome of your original code
Analyse the results of both updated and old test codes simultaneously
Common elements like functions variables and other elements are included in the application
The process isn’t hampered and quick results can be identified

5. Complete Regression Testing

This form of testing involves the examination of existing codes and features before initiating the test. It’s mostly done when the current code undergoes a lot of changes and it allows you to restore any changes that happen during the process. It’s the most favoured test amongst any software testing services providers because of its ability to find bugs in the short period possible.

6. Partial Regression Testing

This testing involves focussing on the modules that may have been affected by the changes in the code. It mostly happens when an additional feature is requested by a client and a code needs to be added here and there. This way only that segment would be tested and not the entire test case.

Certain benefits of partial regression testing include
Easy bugs detection
Saves time
Allows testing without hampering the original code

7. Unit Regression Testing

Unit testing is the most essential component of regression testing. Every time code changes are complete within a unit, the tester again runs all the previous positive test scenarios. Because it focuses on the code in a single unit, it usually conducts it in isolation.

How to Conduct Regression Testing?

Developing a strategy before initiating a testing process is a better way to approach regression testing. Below mentioned are the steps that most QA specialists take to get started.

Steps for Regression Testing

Smoke Test
Collect Tests to Execute
Estimate Time
Identify the Processes to be Automated
Prioritise
Use the Right Tools
Define Entry & Exit Criteria

Step 1: Smoke Testing

Mostly done to check the stability of a system, this check is done to ensure that the system is running as per set requirements. The aim of smoke testing to check if the system is stable even before the testing process is initiated.

Step 2: Collect Tests for Execution

Next, you collect all test cases that you intend to re-execute. As starters, you must include test from error-prone areas of the program as they are likely to be most vulnerable, include a test case that checks the main functions of your product and includes complex cases to check the overall functionality of your application.

Step 3: Estimate Time

Next, you need to identify the amount of time that may be required to test every chosen feature in the above test. You also need to add a buffer period where your testers would take time to identify which tools to use in the process. Additionally, you would need time to create test data, plan and reviewing test cases.

Step 4: Identify the Processes to be Automated

It’s pretty obvious, software test automation services take less time and deliver better-quality results with a limited number of resources. They are more reliable and preferred over manual cases because these test cases can be reused for your next project. This helps you improve the efficiency of your overall software maintenance.

However, in cases of more complex software segments, manual testing is a better option. So, your quality analysts need to establish this segregation on which scripts to be tested manually and which ones to be automated at the beginning of the test.

Step 5: Prioritize

Next, you must identify which sections of your applications are most important and need to be tested first. Below we have divided our tests into three scale priority that can be used to identify which tests to execute first.

P1: All smoke test cases to be tested here

P2: Crucial but not core features to be tested here

P3: Less value test cases necessary to avoid tech debt and further complication to be tested towards the end.

Step 6: Use the Right Tools

After prioritizing, next, you need to identify the right tools for regression testing that may help your analysts to handle planning, preparation and reporting.

Below mentioned are some tools that are most commonly used in the process.

Selenium for Automation
Micro Focus UFT
Watir
IBM Rational Functional Tester

Step 7: Define Entry & Exit Criteria

Last but not the least, you need to define entry and exit criteria to ensure your test objective is aligned with your projects requirements and smoothen the entire process.

Concluding

Regression testing helps ensure your application are free of bugs. It’s important for analysts to ensure regression testing is aligned with the application development process as the test cases used in this can be crucial in determining the quality of your application. We at ImpactQA ensure we deliver the best codes postcode enhancements are implemented. Our team of certified professionals understand your project requirements and deliver the best solution for your projects that aligns with your business goals.

Get in touch with our QA experts for your next testing project.