To Test APIs Effectively—Build an API Regression Suite
All of the ingenuity, innovation, and hard work that go into application development is essentially worthless if the finished product doesn't do what it was supposed to do. Alternatively, if the solution is not comprehensively vetted for potential bugs or errors in the code, security flaws and other issues that devalue the user experience may arise. For all of these reasons and more, establishing an efficient test management strategy is an essential step in creating great software. Herein lies the value of building an API regression suite.
The ABCs of Regression Testing
As each phase of software development occurs, and as subsequent changes are made either to enhance functionality, patch security flaws, or amend a glitch, certain test cases must be run in order to ensure that the alterations are compatible with everything else that came before them. This is not to be confused with simply testing again. Many test cases will have to be repeated, but as TechTarget contributor Mike Kelly notes, that definition misses the point. The purpose of regression testing is to make sure that the thing still works.
"When I think about regression testing, I think about any testing that involves the reuse of tests (manual or automated) or test ideas (regression charters for example – a regression test does not necessarily need to be the exact same test) to manage the risks of change," Kelly writes.
This means that an API regression suite will not necessarily be static. New tests can be added on an as-needed basis, and in some cases, manual testing may become necessary. Keeping this in mind is especially important when it comes to agile software development, considering feedback loops are much faster, and iteration cycles are shorter. This also means that testing teams must have a streamlined approach to regression testing since it will be occurring with more frequency. Anything less than meticulous test management here can pose the risk of an API that doesn't serve the end user.
Where Test Automation Tools Fit In
In theory, DevOps culture, agile development, and continuous development are aimed at greater flexibility in API development. The benefits are speedier time to market, quicker patching, and the ability to respond to consumer demands and changing market conditions at a breakneck pace. To achieve this, testers have begun relying on new testing methodologies, not the least of which is automation integration.
Regression tests are the perfect candidate for software testing automation, mainly because they can be so redundant. By not having to manually run the same test cases time and again, QA teams can save a significant amount of time and reduce the likelihood of introduced errors.
It makes so much sense to run regression tests at the API level in particular because, as noted by TechTarget contributor Yvette Francino, automated testing at the graphics user interface level is somewhat impractical. When it comes to GUI, functionality is a slightly more subjective matter. But at the API level, test management teams can ensure that everything that happens at the GUI level is supported by critical functionality at the base layer. Some exploratory tests can still be automated—and agile testing methodologies are becoming increasingly accommodating on this front—but some regression tests, especially for user experience, may still have to be run manually.
Nevertheless, the contributions of automated testing to an API regression suite are invaluable.
Long-Term Benefits
In the long run, building an API regression suite with a well-rounded test management system that supports collaboration between testers and developers allows for methodical test tracking, and features such as automation integration can enhance the development process as a whole. In addition to better software, the deferred benefits include the ability to reuse test cases for new projects. It also provides QA management with a golden opportunity to restructure their internal processes to make them inherently more agile. In chorus, all of this improves the chances that end users will be satisfied with the API, and this means a better bottom line for your business.
