How to Write Regression Test Cases?

Every company wants to ship reliable and stable software solutions – web or mobile applications. But when the company’s employees work on the product, they develop new functionality or features and of course, make changes in the code. This may increase the risk of introducing bugs into the apps.

Definitely, it is not a good thing when external customers find bugs before your team does. Is it right? 🥴

💪 With regression tests at hand, the team can ensure that new code modifications do not disrupt the existing functionalities of your software products. In this article, we will help you understand what regression testing is across the different testing types, why you need a regression test plan and how to write regression test cases.

Regression Testing: What It Is And When We Need It

Regression testing, as a quality assurance practice, a type of software testing is designed for software and testing teams to re-run types of tests to catch bugs in a software app after code changes, updates, or upgrades have been implemented. However, it is more than just rerunning previous test cases. Teams conduct regression testing generally before the application goes to production, aiming to make sure that newly implemented functions are correct, without new bugs or errors and do not cause them in existing system functionality.

As a rule, the testing teams carry out regression testing in the next situations:

• When the team develops a new feature for the software product
• When the team adds a whole new functionality or feature to the software product
• When the team adds patch fixes or implements changes in the configuration
• When the team releases a new version of the software product – mobile or web application
• When the team optimizes the codebase to improve performance

You should note that even minor changes in the code may lead to costly mistakes for the company if they won’t be properly tested. By applying regression testing, testing teams can maintain software quality and avoid the return of previously identified issues. You can find more information about regression testing in our article here.

Regression Test Plan

Before your teams write regression test cases, they should create their regression testing plan in advance. It is a document with a clearly defined strategy, goals, or scope for the regression testing process. Ideally, this plan should include a list of the features or functions the team has to test, the testing methodology (e.g. align to Agile methodology), the testing approach, the necessary resources, and the planned testing result.

Assumptions and Dependencies

The team needs to consider assumptions and dependencies when they design a regression test plan, because they may affect the success of your plan. So, it is important to take into account the following:

Whether the app’s version is stable and no major architectural changes have been implemented.
Whether the test environment is ready to mimic a real-world setup with all required dependencies and resources.
Whether test cases and data are easy to access for each team member.
Whether the test plan documents all the dependencies and assumptions for other teams, because they also need to collaborate and work on the product.

Key Elements of Regression Test Plan

Source

• Test Cases. You need to define every test for regression testing and check whether they carefully validate all system functionalities based on the test scenarios and requirements.
• Test Environment. Here, teams need to specify the hardware and software configuration (app version/OS/database/dependencies) for regression tests.
• Test Data. Teams need to provide accurate and complete test data. This allows them to cover all possible scenarios for the test cases they are going to use.
• Test Execution. Teams need to organize the test runs with the schedule, timeline, and necessary resources such as team composition, hardware, and software tools.
• Risk Analysis. Here, teams need to think of an effective mitigation strategy that will help them to prevent or maybe avoid possible regression testing risks.
• Defect Management. If the team implements defect management into their workflow, it allows them to report, track, and fix bugs that have been found during software testing activities.
• Test Sign-off. Here, teams should set clear criteria and metrics that will help them complete and approve regression tests. Also, it allows them to reveal if the regression testing process is successful or unsuccessful.
• Documentation. In the well-conducted documentation, the team should keep detailed records of test cases, testing data, results of test runs, and defect logs for future review.

Now, you have a comprehensive test plan at hand and can overview the process of how to write regression test cases below.

How To Write Regression Tests: A Step-By-Step Guide

When the teams are going to write test cases for regression testing, they may face some challenges. We hope that this step-by-step guide will make the process easier. Here are some important steps you need to follow when creating a regression test suite:

#1: Identify Test Scenarios For Better Testing Process Organization

In regression testing, you should understand what changes have been made and what new features have been released or implemented. Only by learning the feature requirements and scope can teams consider all potential scenarios. It will help teams define appropriate test scenarios to repeat the validation of existing ones and create new test cases for regression. Based on these scenarios, you can define how the software will perform under specific conditions (such as responding to user actions, protecting sensitive data, and so on) and assess how tested software processes user inputs and handles different data types, etc. With clear and well-defined test scenarios, QA professionals make sure that the regression testing suite effectively achieves its goals.

#2: Specify Test Cases 

At this step, you need to define test scenarios that allow you to move to a detailed test case design. However, you need to remember that the regression test format sometimes differs for tests that have been written with classical or BDD approaches. In most cases, regression tests are not designed from scratch. Teams often use reusable test cases created before or write test cases for new features on their basis. Furthermore, regression tests are often automated but require detailed cases for tests that adhere to specific standards, for instance, BDD regresion test cases in Gherkin’s plain language. These cases for tests will outline the prerequisites, test steps, test data, expected/actual results, status, and notes.

In addition to that, your tests should be easy and simple so that anyone on the testing team can understand what the goal of the test is. With attachments, screenshots, or recordings added, you can make tests easy to understand.

Below you can find a Test Case Example:

If you are testing login functionality, your tests should clearly state the steps, the credentials to use, and the expected outcome, such as successful login.

#3: Prioritize Tests To Understand What To Test First

At this step, after designing tests, it is imperative to focus on test case prioritization based on their risk and impact, critical features for the smoke tests, and the right time to automate and validate them. Just because you need to identify defects that need immediate attention. You can consider modifications that have an impact on core features, or those that significantly change how the application works, which should always be the top priority. You should take into account the following:

• Scope of code change implemented
• Frequency of use
• Historical number of defects
• Interdependency (a situation where one test case depends on the outcome of another one)
• User feedback
• Pain Points

However, the best way to deal with it is to prioritize the tests according to critical and frequently used software functionalities. When you prioritize the tests based on priority, you can make the regression test suite shorter and save time by executing fast and frequent regression tests.

For example, in a banking application, a test that verifies key functionality like account login or transferring funds should be prioritized over a test case that checks the form style.

#4: Use Automation Testing Tools To Speed Up Testing

With test automation tools, you can enhance regression testing. You can avoid the need for manual testing by creating an automated regression test suite. It becomes possible to rerun tests whenever there are changes in the developed software.

Also, you can integrate them with the test case management system like testomat.io with access to a real-time testing dashboard for monitoring the test execution progress and viewing the test results. It will also work as a central place where every team member can be in the know about managing, organizing, and keeping all tests on track.

#5: Analyze Results and Report For Informed Decision-Making

The last step is an in-depth analysis, where you can get important insights for future test runs. With comprehensive analytics generated from testing results, QA managers and other key stakeholders can quantify testing efficiency, assess resource utilization, and measure the effectiveness of the testing process. Testing reports can reveal weak points in the application for in-time adjustments for the software development team.

If your teams start using tips on how to write regression test cases, they can do it effective manner and may:

• Avoid unexpected results from new code changes or modifications.
• Reduce the risk of post-release issues while also making new releases more stable and reliable.
• Produce software with greater quality by detecting and fixing defects very early.
• Keep software stable and reduce the chances of errors.
• Avoid bugs and keep user experience as smooth as possible
• Fix bugs faster and avoid expensive problems related to production.
• Eliminate the need for manual tests, saving valuable time as well as human resources.

Best Practices: How to Write Regression Test Cases Better

A deep understanding of how to write regression test cases is essential for the entire success of your testing process. Here we are going to explore the five transformative steps that help you reap the benefits:

#1: You Need Organize Tests Into Suites

Organizing a solid test suite helps guarantee effective test coverage. If your tests are well-structured, QA teams can find defects targeted to the app’s core functions. Additionally, it helps them speed up test execution and support defect identification. With detailed test suites, testers may focus on relevant and helpful execution of tests rather than wasting a lot of time deciding what to test, where, when, and how. Well-designed test suites allow quality assurance teams to execute tests that generate results. Also, they can identify defects to make sure that the application meets quality standards and customer expectations. The better the organization of the test suites, the faster tests can be executed and results analyzed.

#2: You Need To Apply Version Control

Implementing version control for your test scripts and cases is essential. You may not only monitor changes but also keep consistency. Version control allows you to see who made the modifications, what changes were done, and when. You can also rollback to previous versions if necessary. Furthermore, you can isolate the source of the problem by identifying what update triggered an issue, as well as improve teamwork by making sure that everyone has access to the most recent tests and the history of changes.

#3: You Need To Work together with Software Engineers

The QA engineers perform a series of tests to identify bugs, glitches, and other issues that may affect the performance and functionality of the product. On the other hand, software engineers create the code and implement new features based on project requirements. When working together, they can tackle quality-related challenges and deliver a successful software product. As a result, they can streamline the agile development process, minimize errors, and improve overall product quality.

#4: You Need to Utilize Automation

The QA team runs regression testing as a part of every release – after developers add new features or handle bug fixes. They should re-execute numerous tests after every code change. While code iterations might be frequent and the functionality is large, regression automation may solve this problem. With the development of automated regression testing tool and frameworks, the regression testing process has become more efficient and reliable.
With test case management integration, the QA team, developers, and stakeholders can monitor and analyze test coverage and execution progress as well as discover which areas of the application have been tested, highlight gaps in test coverage, and show the status of test execution (e.g., passed, failed, blocked).

#5: You Need To Make Regular Updates

Here, with ongoing reviews, you can adapt the regression suite to new changes in the software. They will help you identify obsolete test cases, add new tests, and improve existing ones. It can be done by:

• Discussing comments and planning updates on regular meetings
• Carrying out post-release retrospectives in order to evaluate the effectiveness of the test suite
• Track testing results systematically in a test case management system to discover any blockers or opportunities for further improvements.

These tips help you make sure that the regression test suite remains effective, up-to-date, and aligned with the evolving needs of your software.

Ready to write regression test cases with ease?

Even tiny modifications to the code may result in unexpected bugs in the software and lead to problems you were not prepared for. With regression testing and well-designed regression test cases, you can accelerate the testing process, save resources, and keep the product as stable as possible. If you start incorporating tips and best practices from the article, you can not only streamline your test case creation process but adjust them accordingly to fit your specific requirements. Drop us a line if you have any questions about regression tests.