Skip to content

A Guide to Test Coverage Techniques and Best Practices

Author: Pricilla Bilavendran

Last updated: July 15, 2024

test coverage techniques
Table of Contents

In a previous post focused on the basics of test coverage, we talked about why it’s an essential aspect of software testing to achieve these goals. This time, we’ll be putting the spotlight on test coverage techniques and best practices to ensure the best results. This may be accomplished by creating a thorough test strategy that includes all levels of test coverage. 



Achieving High Test Coverage

Test coverage techniques are key to obtaining great results but need to be included from the outset of the project. Understanding the application’s requirements and use cases from the very beginning is also an important part of the puzzle. 

There are four primary areas to concentrate on in order to obtain high test coverage:

  • Test Planning
  • Test Design Techniques
  • Test Execution
  • Test Coverage Metrics

Now let’s take a closer look into the different aspects to focus on during the above phases.

Identify Areas of Test Coverage: Determine what aspects of your application must be tested and evaluate all sorts of required tests. When establishing the scope of what has to be tested, keep in mind the user’s journey and the various flows inside the application.

Write Unit Tests: Start by creating automated unit tests for all application functionality. Take advantage of code coverage tools to discover any coverage gaps. If you’re not writing any unit tests, collaborate with the development team to learn more about the ones that are already written and ensure that they’re thorough enough.

Use Modular Code: Build programs with a modular architecture, breaking complicated tasks down into small, loosely connected, reusable functions and classes. This will facilitate unit testing.

Employ Static Analysis: Use static analysis tools to examine the code for any flaws. This will assist to decrease the number of possible defects and boost trust in the software’s quality.

Improve Your Test Cases: Determine what kind of tests will be conducted and write complete test cases for each type of test. Look for scenarios that may be difficult to test and devise techniques to make them simpler to test.

Automate Test Execution: Employ automation tools to speed up the process and reduce manual effort. Automated test execution can also provide continuous feedback on test coverage for improved visibility. Automate any manual testing operations, such as data entry, configuration updates, and regression testing. Automation will aid in ensuring that testing is carried out precisely and consistently. 

Track Test Results: Keep track of test results and utilize them to discover areas for improvement. Resolve any difficulties that emerge and run the tests again to confirm the findings.

Review Test Coverage: Keep an eye on the test coverage and compare it to the required level. Consider what areas still need to be addressed and create test cases for them. Examine the scope of the tests and any adjustments that need to be made.

Utilize Third-Party Tools: Make use of third-party tools that are built to automatically test web applications. This can save you time and effort, as well as ensure that you’re testing your web application in a consistent manner.

Focus On Quality: Spend time reworking legacy code and correcting problems to guarantee a high degree of test coverage.

Optimize Test Cases: Optimize the test cases to ensure they are comprehensive and efficient. Make sure the tests are well-structured and regularly updated.

Enable Continuous Integration: Set up a continuous integration (CI) system, such as Jenkins or Travis, to guarantee that tests are executed during development and on each deployment. Tests should be integrated into the development process and included in your continuous integration and delivery pipeline. This ensures that your apps have high-fidelity testing.



Test Coverage Techniques 

Select a Testing Strategy: Determine the breadth of your test coverage and the types of testing that will best accomplish the intended result. Consider including testing for functional, regression, acceptability, unit, system, load, and security.

Prioritize test cases: Prioritizing your test cases will assist you in ensuring that the most essential tests are carried out first. Sort the test cases according to their significance to the application. Begin with your application’s most essential or frequently used features or situations, then go to less crucial or edge cases.

Test early and often: Early and frequent testing helps you catch defects early in the development cycle, which might help you detect bugs before they become costly to fix.

Collaborate with team members: By working together, you may have a deeper knowledge of the application’s behavior and how to test it successfully. Every team member’s expertise is significant, and each team member may add to the application’s greater test coverage. 

Continuously evaluate and modify test coverage: As your application evolves, it’s critical to regularly evaluate and adapt test coverage. This will assist you in ensuring the application has been adequately tested. So keep in mind that this is a continual process, and you should constantly assess and adapt tests.

Use Automation wisely: Automated tests can assist minimize the amount of manual testing required and can remove boring and repeated tests. Automated tests also give higher coverage since they can cover corner cases, edge situations, and all variants of scenarios that would take too long to test manually.

Ensure Adequate Test Data: Adequate test data is required for successful test coverage. Tests may overlook crucial cases or fail in unexpected ways if the correct data is not available.

Invest in Test Design: The quality of test coverage is determined by test design. Time should be spent to ensure that tests cover all possible scenarios, including corner cases, edge cases, and scenarios with varied data. Experimenting with various test methodologies, technologies, and approaches can help discover coverage gaps and generate new ideas for improving test coverage.

Think Defensively: Test coverage should extend beyond a system’s functional needs to search for potential failure from external sources. Defensive testing should include security, performance, and scalability.

Track Test Coverage: Keep track of which test cases have been completed and which still need to be tested. This will aid in identifying coverage gaps and ensuring that all chunks of the application are tested.

Review and Analyze Results: Once the tests have been completed, go over the findings and look for defects or places where coverage might be increased. Defects speak a lot about test coverage. 

Monitor Code Changes: Keep track of code changes and create test cases to cover new code when it’s added or modified.



Best Practices for Improving Your Test Coverage

Now we’ll go through some excellent practices for increasing test coverage. Unit testing approaches, integrated testing strategies, and regression testing methods will be covered. By adhering to these best practices, you can verify that your code has been fully tested and that any modifications made have been thoroughly tested before being deployed into production.

  • Define clear objectives and goals
  • Identify critical areas for testing
  • Use a combination of testing methods
  • Continuously monitor and evaluate test coverage
  • Update test cases regularly
  • Test coverage is a team effort
  • Implement a code coverage tool



In Summary

Test coverage may appear to be a simple concept, yet it plays a critical role in the quality of your product. Implementing the concepts and approaches mentioned in this article will undoubtedly result in optimal test coverage. Try to do research and learn more about your product/system’s behavior, which can help you achieve high test coverage.

Pricilla Bilavendran

Pricila Bilavendran is a test engineer and a certified mentor, currently at Billennium, as well as an advocate for diversity and inclusion. Her experience with Functional, EDI, ETL, Automation, API testing and Postman is part of what she shares in her workshops, webinars, and writing. A global ambassador for the WomenTech Network, and one of the speakers at its 2023 conference, she can be found on LinkedIn, Twitter, and her blog.