Advantages of Using “Service Virtualization” Over “Mocking”

High quality applications, on schedule, under budget, and error free. This is the ideal scenario for developers, testing and operation teams. But this is becoming increasingly difficult as applications become more complex and companies adopt Agile method (characterized by short-cycles, and iterative sprints). This exacerbates testing bottlenecks, where testers cannot test a particular component because it may not be built yet, is undergoing maintenance, owned by third party, costly or restricted. Such components can range from devices, databases, APIs, networks, and more. These dependencies can lead to headaches, increase the time it takes to get to market, increase costs, and may decrease the quality of the application. “Mocking” and “Service Virtualization” allows testers to emulate these components and test independently and in parallel. By emulation I mean how pilots using a flight simulator to train instead of a real plane, or a boxer using a punching bag to train instead of a real fighter. In the context of API Virtualization (a subset of service virtualization), testers can isolate and test APIs by emulating their behavior. This also allows testers to test early in the software development life-cycle and enables frequent, robust testing even when key components are missing from system architecture. API virtualization is often confused with API mocking, but there are many fundamental differences to consider:

Mocking is good for unit testing but very simplistic:

“Mocks” are imitations that emulate real software components for testing purposes. Mocking functions focus on very specific scenarios and contexts  and simulate behavioral responses to fulfill a certain development need. This can be very useful for isolating a specific component from the rest of the application and for performing unit tests. In general, mocking is a static implementation and state-less (responses do not have contextual information), and requires 100% manual configuration. Developers/testers must go through the arduous act of creating new interfaces for each use case. Mocks are not re-usable, not flexible and tough to automate. Mocking is not very robust, and ultimately a simplistic approach that can waste a lot of time.

Virtualization can emulate the full implementation of the service:

Service Virtualization, on the other hand, can emulate the full implementation of the service and provides a more realistic, fully functioning simulated environment that is more robust than just mocking. For example, API virtualization provides you with the capability of quickly recording virtual API responses. These responses can then be used to create other scenarios by linking them to a dataset. Virtualization tools also allow developers to switch between a virtual environment and real asset, and test under a variety of conditions. Furthermore, Virtualization can help you do load tests, performance tests, failure tests, security tests, evaluate integrations, and more.  Components can be used throughout production and testing environments, especially early in the software development lifecycle. Another benefit is that these tests can also be automated. Mocking simulates individual classes while service virtualization can simulate the entire network of services.

We are just scratching the surface….

There are many ways API Virtualization can valuable to you. Read our latest E-Book to learn how virtualization simplifies the process of load testing, performance testing, failure testing, security testing, automated testing, and much more, ensuring that your application’s API’s are good to go when ready. Help your organization gain the upper hand, reduce dependencies, headaches, time to market, costs, and increase quality.