Basics of regression testing for beginners

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Regression testing is an incremental validation technique used to test products. It is intended to verify that new changes to the product during ongoing development do not break existing features. Adding new test cases for each new feature ensures successful regression testing.

Developers may find it unhelpful because not only do they have to fix problems reported through regression, but they also have to keep up with QA to learn about changes that affect system behavior. However, it also presents the tester with the challenge of choosing more relevant, realistic, and repetitive cases.

Regression testing applies to all types of testing models. However, it was more successful in Agile testing. If applied properly, it can significantly reduce testing costs in the long run. It is one of a class of tests designed to build confidence in software that undergoes rapid change without unintended side effects.

Because the range of regression increases, it is not feasible to do this manually. The best approach is to choose an automation framework that is relevant to your testing requirements. Then create a test suite, start test case automation, and reduce manual testing. To take advantage of such a test suite, integrate it with a Jenkins CI tool and have it ready to run every night.

When is it useful to perform regression tests?

We should use regression testing in the following scenarios.

• In products that constantly need to add new features.
• For testing product enhancements, you want to minimize manual testing efforts.
• Verify customer reported defect fixes.
• When a product anticipates changes related to its performance.

What are the advantages of regression testing?

Regression testing works best when done correctly. It improves the quality of tested products and has the following advantages compared with traditional methods.

• Notify us of any side effects that occur due to fixes or enhancements in modules or applications.
• Ensure that previously discovered errors do not recur.
• Not only can it be done manually, but it can be automated using tools.
• It helps to improve the quality of products.
• In products with long life cycles, automation can greatly reduce the amount of manual testing.

What are the disadvantages of regression testing?

Regression testing makes testers’ lives easier when working on large software projects. However, it has some limitations that can be overcome by following the steps described in the next section of this tutorial.

• Without automation, it is difficult to manage the cost of regression testing as the scope of testing grows with each new feature of the product.
• Automated regression requires skilled software engineers.
• Changes to older functionality result in changes to related test cases, which further require version control.
• Testing new features requires adding more cases, which increases maintenance costs.
• It affects the total cost of the project budget.
• Regression tests must be run on any small or large changes that occur in the code, because the smallest changes can degrade existing functionality.

What are the challenges of regression testing?

Regression testing can be difficult for testers in the following scenarios.

• The big one is none. Among the features of the product, more are none. Test cases required for regression.
• Implementing large regression suites takes time and is sometimes not feasible due to time and budget constraints.
• Running regression test suites nightly requires dedicated infrastructure or systems, which incurs additional hardware costs.
• Optimizing the test suite to reduce execution time and achieve maximum test coverage is not at all easy.
• Getting the most out of a regression test suite is a challenge because it requires knowing when to run the suite, after every minor change or build, or when a bunch of bug fixes are available.

How do I select test cases for regression testing?

You already know how important regression testing is to delivering quality products. Test cases are the primary element of regression test planning and contribute the most to its success. Therefore, it is inevitable to choose the most appropriate test case to get the best results. So here are some ideas for you to ponder.

1. Select test cases for the most flawed features.

Identify the areas of your product that have the most errors, and it only takes a few code changes to cause a failure. By looking at the weekly/monthly error reports, you can easily identify the areas causing the most errors. The defects. First, you can add these defects to the regression and then look for increased test coverage for that particular area.

2. Select test cases for the core functions of the product.

Before you start designing regression test cases, it is important to identify the core areas of the product. Therefore, understand the requirements specification, review the product design document and propose the features that are most critical to the product. Therefore, you can continue to select test cases and cover the required functionality. With the traceability matrix, you can confirm test coverage.

For example, in a Web application, regression should cover areas such as logins, dashboards, reports, and other core functions evident on the home page.

3. Focus on test cases in areas recently updated to the product.

In the agile world, requirements change frequently. But most of the time, changes only happen in one part of the product. Once the first version of the product is ready, there can be 20-30% changes due to enhancements or bug fixes. In this case, try to focus on recent changes and add cases that might break existing functionality.

4. Select test cases that cover integration tests.

However, integration testing is part of the software testing process. But some of its tests should also be run with regression tests. It helps rule out any possibility that the product missed important features due to last-minute changes.

For example, a change in the authentication protocol might cause the login API to fail, and fixing the error message might cause the reporting API to fail.

5. Select all end-to-end test cases.

Each product has some key end-to-end business flow that needs to follow a composite sequence of UI operations.

For example, to buy a product from an e-commerce site, first the user needs to find the product from a specific category, select the product, add it to the cart, apply if there is a coupon, select the payment method, provide contact/delivery details and continue to pay.

By adding more operations to the sequence, you can increase the likelihood of finding serious errors. If any operation stumbles from the chain, the whole function can crash. This is why we advocate such complex test cases as part of a regression test suite.

6. Filter test cases based on regression test priority.

We cannot have an ever-increasing and indefinite return. In these cases. We have to stop somewhere, and we should know that by making wise and considered decisions.

So we started categorizing all regression test cases. Has priority categories such as P1 (very high), P2 (high), P3 (medium), etc. Alternatively, you can separate test cases based on their functionality. You can even add labels to filter test cases. It could be a release tag, Service Pack, or Patch tag.

The idea behind separating test cases into several priorities should come from importance and customer impact.

Here are some rules that software testers can apply to define regression test execution.

If the severity and impact of the error is low, it is sufficient to perform a series of tests from priority P1, P2, and P3.

2. If the severity and impact of the error is moderate, all P1 and P2 test cases are executed. However, testers can also run P3 test cases if needed. Incidentally, if bug fixes require the addition of new test cases, they should also be run as part of regression.

3. If the severity and impact of the error are high, all P1 and P2 test cases are executed, including selected P3 test cases.

7. Select test cases to update when old functionality changes.

It’s not often that customers ask to rewrite old functionality. However, such things do happen. Developers must modify it. Testers must therefore respond accordingly.

• A major shift in product functionality.
• The build process/prerequisites have changed.
• Some regression test cases are never executed.
• The regression test cycle consists of only a few selected test cases.
• The test results are expected to deviate significantly from the last execution.

What steps are required to perform regression tests?

The purpose of regression testing is to find errors at various stages of the product lifecycle. To achieve this, QA teams and developers should design an effective regression testing strategy from the start. Here, we have a list of steps that can help regression testing succeed.

Step 1: Establish requirements and target components

It is important to determine whether the product is being developed from scratch or as part of a production under development. After filtering the first part, drill down and isolate the components/modules that have changed. This is how people determine what should be part of regression testing. You should repeat this step every time a module fixes a bug or adds new functionality to the product.

Step 2: Select an automated tool for regression testing.

Choose a bunch of automation tools that meet your testing requirements. Evaluate and determine their strengths and weaknesses. Discuss with business stakeholders, developers, and software test engineers. And identify the right tools for your project or product. Reach agreement with all interested parties on current and future costs. This is a step you need to perform once, so you must be very clear about choosing the right regression testing tool.

Step 3: Define input criteria for regression test cases.

Admission criteria outline the minimum qualifications or requirements to be met before the test can begin. Therefore, test engineers should pay attention to the following.

• Ensure that tests or defects are repeatable and properly documented.
• If it is a defect to be covered in regression, check its history to identify and track regression testing efforts.
• Add regression tests for defects or test requirements.
• Have the test reviewed and approved by stakeholders.

Step 4: Define exit criteria for regression test cases.

Because the scope of regression increases with the arrival of new features and defects, it is important to set exit points. Like the entry criteria, exit criteria define the minimum qualifications or conditions to be met before declaring the end of the testing phase.

• The software test engineer should complete this step during the planning phase and obtain timely approval. Here are some tips to follow.
• Make sure regression tests complete the cycle.
• Check that the required code coverage is in place.
• Don’t miss checking for any serious errors or delay after approval.
• Finally, verify that the regression does not skip any “high risk” areas.

Step 5: Define the execution plan.

After completing the above steps, it’s time to decide on the frequency and schedule of test execution. In general, the best practice is to run regression after any commit has occurred in your code. However, starting all the tests for every small change is a bit much. Therefore, you can split test cases and categorize a few tests to ensure integrity. You can often run sanity. However, you should be prepared to perform a full regression at least once a day.

Since it is not feasible to run regression manually or partially, continuous integration tools like Jenkins are preferred. It will make your life easier. You can use it to configure tests to run any none. Times. It will let you control regression the way you want.