Role of the Test Harness System in Automation and Integration Testing

Test harnesses are used in two contexts: automation testing and integration testing. For automation testing, the test harness specifically includes all the important elements automation requires. For integration testing, the test harness includes the modules and test data that would flow between these modules. We will discuss both of these testing types and their test harnesses in detail.

Automation Testing

In automation testing, a test harness works as a framework that consists of all the test scripts, tools, and test data to drive the testing process. It further stretches to include the results report with all the necessary information to assist developers in identifying and resolving the issues.

Usually, automation is the right choice for testing when executing repetitive tasks, performance testing, data-driven testing, and complex test scenarios.

One example we can take is automating regression testing using a test harness. Suppose a website is undergoing a major redesign to enhance its user interface and functionality. And Selenium WebDriver is a part of the test harness to automate the testing of critical workflows and user interactions. As the developers deploy each latest version of the website, they run the test harness to ensure that all the existing features and functionalities are still working properly. Here, the test harness helps to quickly identify any regressions introduced by the changes and addresses the issues promptly, ensuring a smooth user experience.

Integration Testing

In integration testing, a test harness includes the test data, the modules, stubs, and drivers to run tests. Integration testing requires several components and input data, so having a test harness helps to keep all these elements in place to perform the tests.

Here, the purpose is to determine if there are any problems in the communication between the modules of a system under development. And you can only do that when the modules are available for testing. But with a test harness, you can run integration testing even when modules are unavailable by using stubs and drivers. They both behave the same way as underdeveloped modules and continue the testing process.