The API Testing Primer: Digital Acceleration through Automation

Julius Raja Pillai

APIs (Application Programmable Interfaces), earlier only under the purview of technology, now act as an important catalyst of business expansion. They enable organizations to create business value out of their data, establish rewarding business relationships, and drive new ways for innovation. In fact, APIs are the binding agent that provides much needed structure and cohesiveness between technology ecosystems/platforms and organizations.

A number of industries use APIs to create new products and services, as well as enhance operational efficiencies. For example, certain retailers use APIs to provide the opening hours of the retail locations that are the closest to their users or a supply chain management and vendor service that allows business users to integrate supplier data into workflows, send electronic invoices, and create discounting capabilities. Fintech companies leverage APIs to provide a broader set of payment options for merchants or access to banking information through banking data aggregation. These are just two industry examples and the list is endless.

The growth and availability of APIs has been explosive and there are almost no limitations to their application in varied industries. As API functionality continues to mature, they will be able to provide progressive services, such as driving the widespread adoption of digital wallets and other financial services, empowering ML to execute much more refined business operations, and so on.

The importance of APIs in today’s business landscape

Agile and DevOps are the most commonly used methodologies to develop software applications. In fact, the waterfall model has become a footnote in the history of software development. The emphasis of both these approaches is to shorten the development life cycle and deliver high quality software, quickly and efficiently.

However, both of these methods alone cannot meet the ever growing business demands of rapid deployment. Organizations can benefit greatly from the integration of APIs (Application Program interfaces) with the developed applications. Such integration allows for the consumption and reuse of the software functionalities. APIs can accelerate the delivery of products and services to a large extent, thus providing much needed impetus to application development efforts.

From a technical perspective, APIs enable the communication of disparate systems with each other effectively. From a business perspective, it allows web applications or mobile apps of businesses to access and leverage functionalities and technological capabilities of other applications, which they would have to build from scratch otherwise. For example, ML algorithms, image recognition software, online maps, and so on.

APIs form the central crux of modern programming and have permitted organizations to grow their business at an exponential rate through the sharing of services with other organizations. For example, Walgreens had provided access to its photo printing and pharmacies to third-party developers and their popular applications through APIs.

A huge response from developers ensued; case in point is Printicular, which permitted its users to print photos at Walgreens from either their phones or through their Facebook, Instagram, or Dropbox accounts. This API strategy by Walgreens led to greater customer engagement within their retail stores. The revenue per customer, who interacted with it in the store and through the web or mobile devices was 6 times higher than those who just shopped at their stores.

The integration and leverage of APIs continues to present a golden opportunity for organizations to strengthen their digital offerings, as well as monetize the capabilities of their applications.

The need for API testing

Today, there are over 20,000 services that are exposing APIs across the globe. The large number of available APIs and subsequent billions of API requests and responses being generated, drives the need for API testing.

API is the nerve center of any system or application. It is the collection of tools, protocols, standards, and code that provides structure and strength to the digital world. As a result of its potent nature and fluidic capabilities, APIs enable organizations to become more agile, allow business to go digital quickly, and enables everything to work cohesively in a well-organized, integrated manner.

API testing is carried out at the most crucial layer – business, in which the business logic processing is executed and all transactions between the presentation and database layers occur.

There is no singular test for APIs; you would need to correctly identify the kind of API test to run, based on the specific features of your API. Some of the frequently used API test types include:

  • Unit testing: This type of API testing is carried out to test the functionality of an independent operation.
  • Functional testing: This type of API testing is used to check the functionality of an API. It includes test cases to confirm HTTP response codes, response validation, error codes for API return, and so on.
  • Load testing: This test is run to understand how an API simultaneously manages huge amounts of data, as well as a large number of application users. This test basically checks the performance and functionality of an API under different load conditions.
  • Security/penetration testing: Security testing is very important, as APIs essentially create a communication bridge between two applications. One of the central functions of an API is to conceal one application’s database from the other. It includes test cases, such as authorization checks, session management, and so on. Penetration testing is performed to identify API vulnerabilities.
  • Interoperability testing: It is conducted to check whether the API conforms to the Web Services interoperability profiles.
  • Fuzz testing: This test involves the forceful input of random data to create a forced crash, overflow, or similar negative event. The API is tested to its extreme threshold and can represent a worst case scenario.

Benefits of API testing

Test engineers need to ensure that live API endpoints are up and running and respond quickly by returning the required information. As a result, testing teams can identify when issues occur and fix them, before they are noticed by end users/services. However, some of these shortcomings are not immediately noticeable and could be more critical than just an issue of speed.

It is prudent for organizations to leverage the advantages of API testing, before such changes are deployed to the production environment. It is more relevant to test APIs in both the staging and production environments to authenticate whether or not the software application meets the desired requirements and is performing optimally. Here are some of the benefits that you can derive from API testing:

  • Easy application access: API testing provides direct access to the application, nullifying the need for end user interaction or GUI testing. Test engineers or QA engineers can identify errors earlier, before they affect the GUI and end users.
  •  Cost & time effective: API testing requires less coding and time, which in turn leads to faster test results at a much lower cost and increased test coverage.
  • Language agnostic: API tests exchange data either through XML or JSON. This means that any language can be used for automation, independent from the languages that were used to develop the application.

Automation testing: speed is of the essence

In the realm of software testing, there are two ways to go about it – manual and automated. The primary objectives of both methods are to run the test cases, derive the actual outcome, and compare it with the anticipated results. Manual testing, as the name implies, is performed through human effort. Automation testing is the execution of tests automatically, analysis of test data, and the leveraging of the test results to enhance software quality and performance.

If you are a test engineer or QA engineer, you must already be aware that consecutive development cycles mandate the repeated execution of the same test suite. You must also be aware that this process can be monotonous, as well a huge time killer, if done manually. With the right test automation tool and technique in place, you would be able to write the test suite quickly, execute it in a constant loop, avoid human interference, and improve your testing ROI drastically. 78% of organizations today use test automation for functional and regression testing.

Now that we have understood what automation testing is all about, let’s take a look at how you and your organization can benefit from it:

  • Uncomplicated test execution: Test scripts, through the use of automated testing tools, can be written once and reused multiple times. In the case of manual testing, if a single line in the source code is changed, all the test cases have to be executed again and there is always the possibility of certain tests being omitted. 
  • Minimal to zero human involvement: With automated testing tools, tests can be run unattended, without any human intervention, and for the longest possible time.
  • Faster test execution: UI testing takes time, as it is a step by step process. In automation testing, all of the steps are automatically executed and more steps can be performed at a granular level. Subsequently, this leads to in-depth, increased test coverage.

Coming up next……

So far, we have covered ground on what automation testing is, the importance of APIs in today’s business landscape, need for API testing, types of API testing, and benefits of API testing.

In part 2 of the blog series, we will focus on the challenges involved with API testing, the tools available in the market for API testing, and how they fare, performance wise. Stay glued to your device.


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