APIs have streamlined web development for software applications across industries, from startups to tech giants like Google, Twitter, Facebook, Dropbox and PayPal. No matter the size of your company or the complexity of your software product, strong web API testing practices are essential to ensuring the security of the application’s codebase as well as confirming that all expected interactions occur between the applications.
That’s a lot of boxes to check during QA testing, so where should your team start?
A strong testing process is the result of a solid strategy, so begin your web API unit test process by implementing a plan of action. Before we discuss how to test API during your testing cycle, let’s first answer your most pressing questions about web API testing, such as:
An API - which stands for Application Programming Interface - is a set of functions that allow your software application to access data and interact with external software systems or components. Think of an API as an intermediary between your software application and a third-party system so that both systems can support data integration and cross-collaboration across platforms. Web API testing is the process of ensuring that the API operates properly between systems.
How APIs work is comparable to a dining experience at a restaurant. You are a customer reading the menu at your table and the kitchen is the provider of those menu items. But you as a customer cannot walk into the kitchen to place your order and take it back to your table. And the chefs don’t have time to take your order and deliver it to your table because they need to spend their time preparing your order.
That’s why restaurants have waiters. The waiter takes your order, delivers it to the kitchen and tells the kitchen how to prepare your order. The waiter then brings your food order back to your table.
This is comparable to how an API works. The API sends out your request to the external software resource and delivers its response back to you upon completion.
A web service is a compilation of open source standards and protocols applied towards the exchanging of data between software applications or systems. This definition sounds similar to that of an API, so here’s how you can tell the difference.
In short, all web services are APIs - but not all APIs are web services. That’s because APIs have the ability to interact more progressively between two software systems and carry out more requests. A web service only uses SOAP, REST and XML-RPC as their three styles of communication while APIs can communicate more complexly. A web service is dependent upon a network in order to operate while APIs are functional without a network for operation.
REST - which stands for Representational State Transfer - is a style of architectural for providing programming standards when developing web services so that systems can communicate more easily with each other.
REST-compliant systems (also known as RESTful systems) uphold these six guiding principles:
Even expert QA engineers run into web API testing challenges during every development cycle. As your team becomes more familiar with how to test web API in browser, you will learn how to adjust to testing obstacles more quickly based on past troubleshooting and comfortability with the testing environment. Until then, here are ways on how your team can overcome API testing challenges with successful results.
Testing a web API in browsers starts with having the correct tools. It can be tempting to choose the latest, priciest tool on the market, especially when it promises unparalleled results. But it can ultimately be a waste of time and money if it doesn’t deliver on quality and accuracy across every web API unit test.
Before your initial search, ensure that your team understands how to test API across your software application. Then review a variety of recommended API testing tools and ask yourself these questions during the decision-making process:
The process of testing a web API in browsers can stall when your QA testers do not have all the information needed to complete a web API unit test. For example, if requirements aren’t precise - numeric ranges not specified, date formatting not clarified - then it is impossible for your QA team to pass or fail a test case.
To overcome this challenge, refine your testing process. When drafting test cases, your QA engineer should notice when test information is incomplete. The project manager should then return to the business owner or client in order to provide all needed specifications for the test case to be executed. Furthermore, refining the procedures around gathering business requirements can help your team gather all specifications earlier in the development cycle so that all teams are on the same page.
API calls must appear in a specific order when testing API's. And it’s this specific sequencing that can cause your QA team challenges, especially when working with multiple-threaded applications.
For example, if an API call to return a user’s profile data is submitted before the profile is created, the request can expect an error message. Inversely, an error message occurs when requesting location pins on a map to be placed correctly if a call to create a map hasn’t yet been submitted.
You can confirm that your team knows how to test API based on the benefits received from the testing process. With the right web API unit test process in place, your team can expect to enjoy these advantages of web API testing across development cycles and projects.
Web API testing can’t be effective if your team doesn’t understand how to test web API in browser. A strong API testing process should include these types of software testing to ensure that all API performance, functionality and security are in place.
Can your team use some help with your web API testing process? Choose to partner with a QA services provider like QASource. Our team of engineers and testers have years of experience with API testing and specialize in implementing best API testing practices across your development cycle. Get a free quote today.