Whitepaper: API Testing – Challenges and Best Practices

There are quality risks associated with producing and consuming APIs in today’s API economy. We’ve got five key API testing must-haves to reduce risk and ensure quality.

Learn the best strategies for creating an API testing strategy that ensures quality, reliability, security and performance.


Download the whitepaper to discover the top 5 API testing must-haves.

Key takeaways:
  • Overview on the growth of APIs
  • Risk challenges in today’s API economy
  • Top 5 API testing must-haves
  • Modern composite applications continue to aggregate and consume private, partner and public APIs rapidly. Today, there are nearly 20,000 published APIs – over 2x as many as four years ago. The number of private APIs is estimated in the millions.
  • The integrity of the APIs you produce and consume is critical because the risks associated with application failure have major business impacts.
  • By integrating exposed APIs into business-critical transactions, you’re assuming the risks associated with that API’s integrity.
  • Potential points of failure increase as the number of external APIs integrated into a business process increase.
  • Regardless of where the fault lies, the business impact of any application failure is the same. If your API is popular, you can guarantee that a glitch will make the headlines.
  • The more secure, reliable, and dependable your API, the better the chance of consumption and the greater the potential for business expansion.
  • On the other hand, if you’re providing a questionable interface and there are viable alternatives to your API, you’re likely to lose business since switching costs associated with API integration are so low.
  • Broader attack surface

Exposing an API through an internal infrastructure increases an application’s attack surface area. It could be vulnerable to API-level attacks (injections, payload-based attacks, etc.) as well as exploits that take advantage of ineffective authentication, encryption and access control.

  • Elevated potential for unexpected misuse

Considering the range and number of people who have access to published APIs, it’s inevitable that they’ll be exercised in multiple unexpected ways. People will unknowingly use them in ways the producer never anticipated, and attackers will try to exploit them.

  • Exceptionally unpredictable demand

While APIs typically need to meet established performance SLAs, validating performance vs. SLAs is complicated because it’s so difficult to predict how and when the API might be accessed.

  • API consumers need test environments

To promote widespread adoption of APIs, it’s preferable to provide API consumers test environments (a.k.a. sandboxes) that enable them to develop and test against exposed services with zero impact on the production system.

  1. Intelligent test creation and automated validation

With APIs, testing a broad range of conditions and corner cases is critical, so automation comes to the forefront. The creation and execution of simple automated tests with limited or manual validation might have sufficed for internal given web services that were used internally (e.g., via SOA), but more sophisticated and extensive automation is required to be confident that APIs are robust enough to meet business expectations.

  1. Change management for test assets and environments

A system for fast, easy and accurate updating of test assets is critical for keeping test assets in sync with the changing API. If you can automatically assess the impact of changes to existing tests and quickly update existing tests (or create new ones) in response to the identified change impacts, you can vastly reduce the amount of time required to ensure that your tests don’t fail due to expected changes or overlook critical new functionality.

  1. Service virtualization for simulated test environments

With service virtualization, you can create simulated test environments that provide access to the behavior of dependent resources that are unavailable, difficult to access, or difficult to configure for development or testing.

  1. Extensive performance testing with service virtualization

Due to the highly exposed nature of APIs, there’s a high potential for unpredictable and volatile traffic volumes. To determine whether your API will satisfy SLAs in the event of the erratic or surging demand that APIs commonly face, it’s essential to ramp up the scope of performance testing.

  1. Extensive security testing (with service virtualization

With the increasing attack surface area of APIs, a multi-faceted security testing strategy is essential to ensure you have built the appropriate level of security into your application.

  • Building a comprehensive set of API tests is critical in order to guarantee that your APIs will take on only a reasonable level of risk.
  • To tackle the challenges of building all necessary test cases to cover requirements, it is imperative to rely on a solution that can take you to the next level.
  • Most importantly, taking advantage of service virtualization helps you make certain the proper test environment is available on demand.

About Parasoft

Parasoft’s software testing solutions support the entire software development process, from when the developer writes the first line of code all the way through unit and functional testing, to performance and security testing, leveraging simulated test environments along the way. Parasoft's unique analytics platform aggregates data from across all testing practices, providing insights up and down the testing pyramid to enable organizations to succeed in today's most strategic development initiatives, including Agile/DevOps, Continuous Testing, and the complexities of IoT. Parasoft’s automated software testing innovations fuel software development organizations, helping teams reduce the time, cost, and effort of delivering high-quality software to the market.