3 Reasons Why Test Coverage Is Important in API Development

Posted on Jan 21 2020 by in Blog Blog Post Blogs 

When it comes to API development, testing your product is an absolute must. After all, even the most proficient development teams are prone to making errors both big and small, and developers should practice due diligence in checking for errors before the final release.

However, this does not mean that companies can haphazardly run random tests and assume all is working according to plan. Some of the most debilitating errors occur in places where developers least expect it. This tends to happen because of a failure to conduct the right kinds and numbers of tests during the development cycle. Unfortunately, improperly tested or untested areas can lead to disastrous results.

This is where the importance of test coverage comes into play. In this phase of development, teams must be able to determine what exactly they are testing, the amount of testing done, and the effectiveness of the tests conducted. This can be accomplished using data gathered by a comprehensive API testing tool for developers, which will allow them to:

1. Determine if the API can perform its basic requirements.

To set a sound foundation for test cases, teams should be able to determine the main purpose of the API. No matter how sleek or speedy the product is, if it is not able to meet the end-users’ expectations, then it has failed on a fundamental level.

This can be likened to the testing of, say, a writing pen. If the end-users require it to use black ink, filling it with blue ink will immediately be considered a failure to comply with their requirements.

A similar concept applies to API testing, where the build should be able to match all the end-users’ requirements. Hence, developers should regularly consult the requirement document and make sure that the API is on the right track.

2. Pinpoint crucial aspects of the API that may have been overlooked.

While it’s important to make sure the main requirements are functioning correctly, developers should not concentrate solely on those features at the expense of everything else, either.

Going back to the example of testing a pen, one should not be focused only on its ability to dispense ink correctly. It’s also important to check whether its current form makes it comfortable to hold for long periods of writing, among other things.

In the same vein, developers must also identify other aspects of an API that may not immediately come to mind but are equally as relevant to the end-users’ experience. For instance, is the API able to run simultaneously with other APIs? Are error messages easy for end-users to understand and troubleshoot on their own?

3. Identify any possible risks that could negatively impact performance.

Developers often make the mistake of only putting an API through its paces based on ideal test cases. The thing is, it is just as important to factor in any potential risks that the API may be exposed to.

To compare this with the metaphor of pen testing, it may work fine when tested in a controlled environment, such as while writing on a desk. However, it may not have been tested for use in areas with warmer climates or while on a plane. Higher temperatures or a change in air pressure may cause the ink to leak, ruining the user’s bag, purse, or shirt without warning.

Similarly, APIs may break in certain scenarios that were not accounted for. For example, an API may run normally with an ideal number of users but may break if an unexpectedly large number of people access it at the same time.

By keeping these sorts of possibilities in mind, test coverage can help teams uncover any major vulnerabilities in the code, preventing an API from failing in the first place.

Even a single fatal error can make or break an API’s success. Thus, if a company wishes to keep customer trust, maintaining a high standard of quality should be a top priority. Test coverage ensures that no stone is left unturned, resulting in a stable and reliable final build. By regularly conducting comprehensive testing both manually and automatically, API designers can cover all their bases and prevent major issues from occurring.