Implementing a Single Framework for API and UI Testing
  März 05, 2019

We constantly hear about API and UI testing together, but what does that actually look like in implementation?

In a recent SmartBear webinar, “Implementing a Single Framework for API and UI Testing,” we discussed the importance of testing at the API and UI level, how building a single framework for both with help with faster development cycles, and how it all circles back to the goal of DevOps.

During the webinar, we asked our audience which layer they're responsible for testing, and 67% responded with both the API and UI layer. While the majority of organizations seem to be testing both layers, there are still many teams that are focusing on one or the other, or that don’t have a framework in place to test both effectively.

The following are some of the main takeaways from the webinar to help teams that are currently testing at both layers as well as those who want to incorporate more of either API or UI testing.

The Importance of Testing the API and UI

What are the benefits of testing both the UI and API layers?

The UI is what we see when we interact with an application, and automating at this level means you’re able to capture and recognize objects such as text, images, and other visual elements.

When you’re automating at the UI layer, you’re evaluating user experience, layout errors, cross-browser issues, and the presentation of data in the UI.

You’re also validating multiple systems and services at the UI layer. This is crucial to look at an application from the user perspective and test important user workflows.

However, testing at the UI doesn’t account for business logic, boundary errors, and data variants. Additionally, while you can test and validate multiple systems at the UI level, this takes much longer to automate.

The API, on the other hand, acts as an interface working behind the scenes to talk to other services, which means there are a lot of connections that need to be tested.

Testing at the API layer means confirming information is being exchanged between other databases to create and deliver services, making it the ideal place for data testing. You can also test business logic with faster test execution and faster root cause analysis when you automate at the API layer.

Tests at the API layer are also less brittle and easier to maintain. Because it’s based on getting simple responses in exchange for simple requests, it doesn’t consider cosmetic characteristics such as color or layout.

As you can see, testing both layers is essential. With an API and UI testing framework in place, you’ll have much higher test coverage.

What Goes Into a UI and API Testing Framework

Most of us are familiar with the testing pyramid, which gives us a foundation for forming a testing framework.


  • Unit testing is at the lowest level and provides a foundational functionality assessment.
  • Integration tests take changes and brings them into an existing system to see how they react. They may look and function correctly in isolation, but what happens once they’re connected?
  • End-to-end testing ensures the complete functionality of your software because, when something fails in the highly integrated system that is your application, it can affect the entire product.
  • UI testing is important since the UI might be looking different even with the API functioning properly. Most of the cost is in maintenance, which is why there are the least number of UI tests but the most crucial workflows.

You can then take this framework and augment it with a test automation tool in order to become a better and faster QA professional.

How SmartBear Does It

We support UI and API testing by allowing you to transfer data between the two layers in a single framework with SoapUI Pro and TestComplete. Together the benefits are having enhanced performance, faster maintenance, and extensive reuse.

  • Extensive Reuse - Extensive reuse is the aspect of having a single framework throughout your delivery pipeline to increase efficiency and optimize test automation. We enable maximum reusability, allowing API tests to be reused and enabling the sharing of test data between UI and API layers.
  • Reduce Maintenance - You’ll experience faster maintenance by having a single validation point for your API and UI tests. Data driving UI tests and leveraging the same data variables in your API tests will ensure front-end and back-end test coverage. Then, when you update one data source, it cascades changes to all your UI and API tests to make test maintenance infinitely easier.
  • Enhanced Performance - End-to-end testing provides a perspective on the performance of your software across different environments. Performance comes into play when you’re able to run API tests before, after, or in the middle of UI tests without having to have both applications running.
  • Tools That Fit Into Your Ecosystem - Integrate with your favorite tools that you already use in your workflows. We have native plugins and integrations for the CI/CD servers inside your ecosystem.

With these tools, you can run automated end-to-end tests that will aid you in your DevOps journey. By expanding test coverage while reducing time and costs, you can ultimately release a better product to your users, faster.

The Need for Automation in DevOps

At its simplest, DevOps is about removing the barriers between three traditionally siloed teams -- development, test, and operations -- to release high-quality software faster.

As organizations continue to investigate the best way to accomplish DevOps, it often comes down to a few basic needs. This includes saving time, proactive input, improving accuracy, increasing test coverage, and increasing team ownership of testing.

Incorporating test automation is the first step towards achieving these goals. Meanwhile, there’s a high demand for automation knowledge on both sides. Test automation for both the API and UI layers is a must-have skill for QA professionals in 2019 -- the proof is in job listings for QA testers or engineers that have all included knowledge or experience in a test automation framework.

Implementing a single framework for API and UI testing is the key to understanding your application end-to-end, so you can address issues of quality at the source of the problem.

Want to learn more? Watch the full webinar below: