Highlights:
- In agile software development, with a focus on iterative and frequent code updates, regression testing services play a pivotal role in preventing the disruption of existing functionality.
- The execution sequence is determined by the priority assigned to each test case, with high-priority test cases taking precedence, followed by medium and low-priority cases.
Modifying a large, interconnected codebase presents a considerable challenge. Be it introducing new features, bug fixes, or enhancements, the potential for unintended consequences that can disrupt your application or website is ever-present.
Although automated tests, such as unit tests, are critical for tackling such issues, this comprehensive guide on regression testing offers insight into the importance of how it is conducted, the various methods, and the future of the testing mechanism.
What is Regression Testing, and Why is it Important?
Regression testing tools are a critical phase in the software development cycle, verifying that each change made to the codebase does not inadvertently introduce new issues or rekindle old bugs. This practice is precious in projects without stringent version control systems, where tracing the origin of a bug can be challenging.
A robust approach to the testing involves crafting tests specifically tailored to known issues and consistently re-running them after code modifications. This proactive strategy helps promptly identify any changes that might reintroduce a previously resolved bug.
In agile software development, with a focus on iterative and frequent code updates, regression testing services play a pivotal role in preventing the disruption of existing functionality.
This example underscores the significance of the testing mechanism in maintaining software quality.
How to Conduct Regression Testing?
Typically, there’s no set pattern for implementing the testing process. A quality assurance (QA) analyst should consider several popular regression testing strategies.
Step 1: Selecting the regression test
In this phase, known as ‘retesting,’ you specifically choose test cases that require validation. Instead of testing the complete suite, your attention is directed to the module that underwent modifications in the source code.
The selected test cases are then categorized into two groups: (i) reusable test cases, which are preserved for future regression cycles, and (ii) obsolete test cases, which are not considered for upcoming testing cycles.
Here are the tricks to identify the reusable test cases:
- Tend to be prone to errors
- Validate the app’s functionality
- Encompass user-visible features
- Include recent modifications in the source code
- Demonstrate a history of successful execution
- Encountered failures in prior testing phases
- Pertain to integration aspects
- Involve boundary-value considerations
Step 2: Determine the time for executing test cases
The subsequent stage involves assessing the expected duration for running the chosen test cases. Several factors impact the execution time, including test data generation, regression test planning orchestrated by the QA team, comprehensive test case reviews, and various other considerations.
Step 3: Identify the test cases that can be automated
Building upon the outcomes of exploratory testing, the QA team can make informed choices about which test cases to automate. Automated test cases are advantageous for their speed and reusability. Consequently, the test cases can be categorized into two groups: (i) manual and (ii) automated tests.
Step 4: Test case prioritization
In this stage, you collect all the test cases and segment them into priority levels such as high, medium, and low. The execution sequence is determined by the priority assigned to each test case, with high-priority test cases taking precedence, followed by medium and low-priority cases. The priority allocation is based on the product’s functionality and significance to users.
The prioritization structure follows a waterfall approach with three levels:
- Priority 1: These are the most critical test cases, encompassing all core functionalities.
- Priority 2: These test cases cover essential features not part of the core functionality.
- Priority 3: Test cases addressing technical debt and improving the system’s quality.
Step 5: Executing test cases
Finally, it’s time to systematically execute each test case to ensure the product functions correctly. Depending on your needs, you can choose either manual or automated testing. For automated regression testing, using functional testing tools like Selenium, QTP, Watir, and others can expedite the test case execution process.
Now that you understand how to plan for the testing process, the next question to address is the commonly used methods for regression testing. Let’s explore that in the next section.
What Are The Various Regression Testing Methods?
The four most popular regression testing methods are:
- Regression test selection: In this method, specific test cases that require retesting are chosen.
- Test case prioritization: All test cases are gathered and prioritized based on importance.
- Retest all: The entire regression suite testing is retested.
- Hybrid: This method combines the test selection and case prioritization for more efficient testing.
Out of all these methods, the hybrid approach proves to be the most efficient. It offers the benefit of conducting regression test selection or test case prioritization before executing the required test cases, resulting in significant time and effort savings.
The Future of Regression Testing
It should be considered a vital component of a comprehensive testing methodology to ensure effective regression testing. This approach is cost-effective and efficient, encompassing a variety of testing methods. It combines well-designed frontend UI automated tests with targeted unit testing, prioritized based on smart risk assessment. Such a strategy ensures that no aspects of your software applications are overlooked.
In today’s agile work environments, employing methodologies like XP, RUP, or Scrum, regression tests are recognized as essential for dynamic, iterative development and deployment schedules. Regardless of your organization’s software development and quality assurance process, meticulous upfront planning and a diverse testing strategy, with automated regression testing at its core, can prevent budget overruns, keep your team on course, and, most importantly, safeguard your products and your company’s profitability by preventing unexpected bugs.
Final Words
Regression testing is a pivotal phase in the modern software development cycle assuring that code changes don’t inadvertently introduce new issues or revive past bugs. This practice is precious in projects lacking stringent version control systems, where tracing the origin of a bug can be challenging.
A robust approach involves crafting tests tailored to known issues and consistently re-running them after code modifications, promptly identifying changes that might reintroduce a resolved bug. In agile development, with frequent code updates, regression testing is vital to safeguard existing functionality. This proactive strategy ensures software quality is upheld.
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