API Testing Automation: How and Why Automate API Testing

APIs are everywhere, and in most cases, we don’t give them much thought, even when using them multiple times a day. Whenever you log into a website using your Google or Facebook account, check the location of a new restaurant on Google Maps right from the restaurant’s website, or pay for your purchase on an eCommerce site using your PayPal account, you get to witness APIs in action.

But while APIs usually serve a single purpose and are not particularly large or complex software products, it takes a lot of testing on the developers’ side to ensure the spotless performance, complete functionality, and strong security of an API. And many organizations now prefer to automate API testing to save time and money on QA and get more consistent results. In today’s guide, we are going to talk about why and how to use API automation testing in your company.

What Is API Testing & How Is It Different From Other Types of Testing?

API testing is the process of verifying the correct operation of an API (Application Programming Interface) by interacting directly with the application, bypassing the user interface. As more and more businesses rely on API technology to offer more robust functionality to their users and surpass the competition, API testing becomes a mainstay of any current software development and QA project.

API testing is also an important part of the switch from the monolith architecture to microservices. A growing number of companies prefer to build flexible and scalable solutions consisting of multiple smaller units such as APIs instead of large, monolithic systems. On the one hand, this leads to the development of handy software solutions with a specific purpose. On the other hand, it creates the need to test each unit or API separately and in combination with other units.

“One of the biggest differences between API testing and other levels and types of testing is the approach to testing itself. Instead of simulating the behavior of an end user, like you do with UI testing, in API testing, you make sure that the product is working properly regardless of the user’s behavior. Plus, API testing costs less and is easier to perform than many other types of quality assurance.”

Taras Oleksyn, Head of AQA, TestFort

Why Automate API Testing?

As with many other types and levels of software testing, it’s possible to do API testing entirely manually. However, automating the process brings some sizable benefits to the whole software development and QA operation. Here are a few reasons why API testing is important and deserves your utmost attention:

• Automating API testing allows you to catch bugs earlier before they do more damage to the entire product or stall the development process.
• Automated API testing provides nearly endless test case reusability opportunities, resulting in more efficient testing and API products being developed faster.
• API test automation eliminates the risk of human error skewering the results of testing, misinterpreting the results, or skipping some essential steps in the testing process.
• While automating API tests requires financial investment in the initial stages, test case reusability allows the organization to save money on testing in the long run.
• API testing automation improves the performance, security, and scalability of a software solution that uses API technology more noticeably than manual testing.

The Role of API Testing Automation in API-First Development

A relatively new trend among software development companies and businesses developing their software is the API-first approach. Under this approach, development teams build software applications by linking together several different APIs. This is a product-centric framework that emphasizes the functionality brought by external services through APIs. And with teams often racing against the clock to unveil better products faster than their competitors, continuous and effective API testing, especially API testing automation, can significantly improve the QA process and lead to higher quality software that is released according to schedule.

Is It Always a Good Idea To Automate API Testing?

The benefits of API automation testing seem far too vast for anyone to doubt the usefulness of this QA technique. But does it always make sense to automate API testing within an organization?

From a practical standpoint, automation is typically not needed on small testing projects that are not expected to be long-term. Automation API testing may also be redundant when there isn’t a substantial regression test suite to take care of, as automation techniques work perfectly with regression testing.

The situation where automating API testing makes perfect sense and is needed is when the API is the product that is being developed, as opposed to being just another component of a bigger product. With the reputation of the company riding on the quality of the API, rigorous testing, including automated QA, is a must.

Types of API Automation Testing

The goal of API testing automation is to test the API at every level and to make sure it’s prepared to be used by its end customers. This is why it’s possible to break down the overall process of API automation testing into specific types of tests that are designed to check different areas of the product. These are the most commonly used types of API automated testing.

1. Functional Testing

As one of the most vital types of API testing, functional testing is responsible for verifying the correct operation of the API’s principal functions. In other words, this type of testing is performed to make sure that the API is doing everything it was originally intended to do.

2. UI Testing

While UI testing does not directly deal with testing the API itself, it performs another important function in the API testing process by investigating all the ways the API is tied into the user interface of the application and vice versa.

3. Validation Testing

Validation testing typically happens at the last stages of the API development process. It is meant to verify various aspects of the product, including correct operation and the presence of all design elements. A successfully passed validation test means the product is ready for release.

4. Load Testing

Since APIs are often designed to work with large amounts of data and under different circumstances, load testing is vital for making sure that the API can handle both normal and peak numbers of requests.

5. Security Testing

Often dealing with sensitive company or customer data, APIs can undoubtedly benefit from security testing. This can also include penetration testing as a subset of security testing, while automation can further streamline the process and make it more efficient.

Who Can Do API Automation Testing? What Skills and Competencies Are Required?

The common opinion in the testing community is that API testing automation is not the most complex type or level of testing. This is why this process does not strictly require a senior automation QA or a lead to be involved. 

“You don’t always need a senior-level automation tester to perform API automation testing. Even when you don’t have any automation QAs on a project, the job can be successfully done by manual QAs or software developers. It’s all about the context and the available resources. If you can afford the time and money it takes to train your manual QAs or developers to automate API testing, then you can get away with having no automation QAs on a project.”

Taras Oleksyn, Head of AQA, TestFort