Pitting API Testing Against UI Testing
What is API testing?
Before we get to the problem of identifying which of the two, API testing and UI testing, is easier or more difficult, we need to begin by defining them. Especially the former. But it comes with a caveat. API testing can cover several different and distinct concepts and knowing which one you’re interested in is often dependent on your role in a software testing company.
If you’re a system tester, API testing brings your team a new way of testing the functionality of software which may be difficult to assess using the UI. This is especially true in instances where API calls are related to error handling or when API responses are only triggered in certain exceptional cases. More often than not, you’ll find it is less painstaking to test these calls directly, rather than try and fix the UI in the right state.
On the surface level, API testing is pretty easy and straightforward. Most software testing teams have well-defined test case management software with decent enough documentation. This refers to how well you know each call and its corresponding responses. All that is required now to do is send a sequence of calls to the API and verify its responses — after all, testing is just a matter of ensuring that you get the expected response for every call. Easy stuff, right?
Why is UI testing usually so difficult?
In UI testing, life is often far more complicated. After all, you would like to start out by defining complete test cases. You can’t simply test the function you would like. Instead, you’ve got to start out by navigating to the right part of the UI and putting the system within the right state. This suggests you would like an entire UI before you’ll start the testing. Moreover, the size of recent UIs makes test automation a must-have. The simple matter of fact in the case is this: automated UI testing itself is a hard problem. Tests are slow to make, they’re hard to research, and they break whenever your UI changes.
The reality is, API testing is perhaps harder than you think it might be. It must go much further than simply checking each response. Other important aspects may include validating error conditions, testing how it handles any malformed calls and security testing. All of those need careful thought and planning. Full API testing must also be conducted with pseudo-realistic data. Without this sort of data at hand, you can’t verify how well it copes with unusual data. As an example, how are you able to test whether your user management API deals well with names that have accents?
It’s important to remember that software testing is a continuum and not to be treated like a discrete series of steps. Instead of asking which is simpler, you ought to be asking, how can UI testing and API testing go hand-in-hand. If you’re looking for a test case management software to keep track of your UI and API tests, try Kualitee today.
