nterface (API) testing, part of the integration testing process, aims to ensure APIs work optimally by identifying bugs in the programming that developers can fix. The process differs from other types of testing by functioning entirely on the data level of the application, ignoring issues like the GUI and ease of use. Bugs related to API testing fall into functionality, reliability, performance, and security classifications that ask specific questions about how well the API does its job.

Functionality Bugs: Does API Testing Work?

Before looking at how well the API performs, the tests need to determine if the API functions at all, and if it works as intended. This starts with checking basic functionally like creating and deleting data via API calls as appropriate. The tests also look for missing functionality bugs where the API calls for a feature that isn’t there.

Once the functionality is there, the API test criteria are used to vet actions to determine if arguments and actions are working correctly. For cases that aren’t working correctly, the testing focuses on handling errors and warnings accuracy. The tests also examine if the API is handling errors in a way that avoids unnecessary crashes. Finally the API tests examine if response data is correctly handled and formatted to specifications. This step checks if the REST or SOAP requests are valid, and if the returned JSON or XML data is properly formatted.

Reliability Bugs: Does API Testing Work Consistently?

Getting the API to work once is a good start, but the API needs to work every time. API testing helps identify bugs pertaining to integration across different systems. Just because one application and server are working with the API, this doesn’t mean different servers and other applications are experiencing the same reliability. Additionally, the tests help identify connectivity issues related to getting a response from the API.

Performance Bugs: Does API Testing Work Under Stress?

Stress testing is an essential part of the API testing process, identifying performance problems with hosting infrastructure and the API itself. The tests help determine how much traffic the system can handle before being overloaded, and how to expand infrastructure to meet rising demand at the core, but also are very effective at pinpointing weak points in the API. The test will look at things like whether multi-threading is working correctly for efficiency reasons; failure to multi-thread can build a huge queue that either overloads or crashes the system. Monitoring helps keep an eye on performance-hindering bugs that are introduced via updates by looking for increases in response times. Initial tests may also identify bottleneck bugs through high response time results. API testing also looks for inefficient, redundant code, which hurts capacity.

Security Bugs: Does API Testing Protect Data Exchanges?

Finally, API testing finds security-related bugs. API calls move data between endpoints which, if unprotected, could be intercepted and abused by hackers. Even if the data isn’t confidential, a business owes it to its customers to keep data exchanges private. The test examines if data being sent over HTTP is correctly encrypted.

If your company is looking to improve API performance and spend debugging time more efficiently, contact the API testing experts at Apica today.