APIs are processes and tools used by developers as a toolkit to develop various types of applications. Often, these are used to connect two systems together, such as for exchanging information or syncing together.
However, to make such connections function properly, developers have to follow the standard protocols and then test rigorously to make sure nothing goes wrong when the product runs. What, specifically, are the developers looking for?
The Largest Concerns in API Testing
The following four items are among essential considerations if you’re going to test an API between systems.
Obviously, you need to make sure the system works. Typically, when one system sends a piece of information, the other will respond with a piece of feedback that acknowledges receipt. It’s like a digital handshake. Your first job will be to make sure this “handshake” takes place. If it doesn’t, under your initial conditions, it means something is not right with the connection, and you may have to start from scratch. Otherwise, you can move on to other areas of concern.
Some applications are intended for pure entertainment purposes, but most feature some degree of sensitivity. For example, in a system that exchanges patient health care information, data privacy is of paramount concern. In financial systems, encryption and protection of data are vital to prevent identity theft and protect consumers. API connections should be fully secured at all times; even a tiny vulnerability could potentially put thousands of consumers at risk, depending on the size of the system. If you’re working with a well-established API, such as one that comes from a major financial third party, this is usually taken care of, but it’s not something you can afford to overlook.
Let’s say your system is functional...but is it functional under a variety of different conditions? Most systems aren’t going to run consistently; instead, they’re going to see a wide variety of different loads and types of inputs, and that variance could make a standard functional system non-functional or unreliable. Being able to test successfully and repeatedly is key to establishing a solid connection.
Finally, you’ll need to tinker with performance. Functionality, security, and reliability are inarguably larger concerns, but once they are in place, you can start worrying about the quality of your systems performance. How quickly are your systems communicating with one another? Is there a more efficient way to handle these communications? The more efficient and elegant your system is, the better it will be for the people who will use it.
Best Practices for Newbies
If you’re new to APIs, don’t panic. Here are a few helpful tips to ensure your tests go smoothly.
Test Calls Individually and in a Group
Most APIs have multiple call-and-response protocols. If you can, try to test these calls both individually and in varying kinds of groups. This will help you pinpoint the roots of your problems, if you face any, and will ensure a better overall understanding of how well your systems are interacting.
Change Load Conditions
Most API exchanges start to break down when the load on the system becomes substantial. It may be too much for your API to handle. Test a variety of load conditions to see where the breaking point is, and develop a workaround, if necessary (such as a queuing system to handle requests).
Experiment with using different variables, such as varying amounts of data or other less-than-ideal conditions. The more you experiment, the better you’ll understand the system (and the more problems you’ll be able to unearth before the system goes live).
It should go without saying, but you’ll want to be thorough in your testing. The worst problems you’ll face are going to be the subtle ones that are nearly impossible to find.
Following these tips and understanding the magnitude of your work are worthwhile to prevent a catastrophe. It may seem like an intimidating responsibility at first, but the more accustomed you grow to monitoring API exchanges and fixing bugs, the more confident you’ll be in your abilities.
In the meantime, err on the side of caution and leave no stone unturned.