Automate your regression with open-source software

21 September 2016Radek Lawgmin

What is AET?


AET is an acronym formed from:

  • Automated
  • Exploratory
  • Testing

It is a testing tool developed by Cognifide to aid front-end side layout testing.  In particular for: 

  • testing websites or platforms
  • regression tests at the end of an hourly/daily/weekly/per sprint completion
  • testing as a part of an upgrade or migration of infrastructure/platform project
  • to help testers and developers ensure that a change in one part of the software does not introduced new defects in other parts of the software

The screenshot illustrates in red the changes between a baseline on the right and the new one on the left.

AET sample report - screenshot comparison


The tool is very useful in regression testing. It allows for efficient and systematic:

  • layout comparison (with big screens and masks)
  • W3C source compliance check
  • source code comparison
  • status code verification
  • responsiveness test-out
  • accessibility evaluation
  • JS errors check

You can access reports through your internet browser which means they can be analysed from any place, at any time. This is hugely useful when you are working with a project team dispersed across different geographies and time zones.

How does it work?

Working with AET starts with configuration of the Test Suite. The user can define the list of URLs to be tested and which tests are to be performed. Once the job is launched and patterns are collected, the tool produces a report which will show:

  • layout comparison
  • Responsiveness - using different resolutions
  • source code comparison
  • W3C source compliance
  • HTTP status code verification
  • JS errors check
  • accessibility

A typical sample report might look like this:


The user can launch the suite as often as they need to. Once set, the pattern can easily be changed, at any time, with just one click. The tool has been integrated with Jenkins, which means that you can run tests as Jenkins jobs and have each job status reported, thanks to the use of JUnit and Thresholds.


Regression testing can be very time-consuming and expensive and is not sympathetic to human error. With AET all of these problems are eliminated. Its quick configuration, test speed, time and cost reduction, reusability and easy maintenance not only increase test efficiency but also increase software quality.

AET goes Open Source

The newest version of the tool has been released as an Open Source project under the Apache 2.0 license on GitHub. The code is available at here.  

What’s next?

We are constantly developing new features to make AET even more useful.  Regular updates mean that we can meet the requirements of the users we support on a daily basis and make them even more efficient. Here are some of the features on the road map:

  • report UX improvements
  • Selenium grid
  • more browser and device support including mobiles
  • performance testing
  • light and more scalable architecture

Your reputation as a developer is based solely on the sites and pages that you create. It is almost impossible to make sure that every single page looks exactly as you want it to without time-consuming and expensive regression testing. Why not make it cheaper, more reliable and efficient with open-source AET?

If you would like to find out more, drop us an email.

Author: Radek Lawgmin
Published: 21 September 2016
AETautomationQAopen sourcetool

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