Have you ever wondered if web pages have been correctly rendered? How application is getting rendered on different browsers? What about Layouts, images and the list goes on. Even a small distortion in the UI can result in loss of business. So, that’s the reason visual testing is an important testing and should be part of your testing strategy. Well, by now already a lot of things are happening around it & in this blog, we will try to explore more about it.
What is Visual Testing?
Visual testing aims at verifying all of the visual aspects for the application under development. It aims at verifying if the correct data and content are getting displayed at the application’s front end. It also validates the appearance & layout of for the complete user interface.
So, how it works?
There are several testing methods, tools and approaches to perform visual testing of applications over different configurations & environment. There are a wide variety of open source and commercial tools available for automated testing.
A visual regression testing tool captures screenshots of the current UI and compares them with the original screenshots & look for the historical differences. It confirms that the web page still renders as expected across various browsers.
In General, there are two main approaches - Code-based and Configuration based, same is applied for tools and testing practice. You can have dedicated Visual Tests or if already functional tests exist then add visual test into the same flows at logical check points or say validations steps.
Best would be to have an automated visual testing – benefits are many, say it is efficiency, accuracy, cost saving, eliminating human error, speed and so on. Also to note, many a times defects are temporary and hard to reproduce, automation can help here as it will capture the screenshot for the issue and reports/logs can be very useful while raising a defect which will help development team with more information.
Choosing write tool:
Well, there is a wide variety of tools available in the market for automated visual testing. but one must understand the scope and choose the correct with long term vision in mind.
Let’s check some of the open source tools
Phantom CSS – It is one of the popular tools which uses CasperJS to take the screenshots and compares them with the baseline screenshots using Resemble.js. It is script based & open source.
FBSnapshotTestCase – It is also code based & open source. It uses XCTest.
Galen Framework – It is configuration based tool and runs in Selenium Grid.
BackstopJS – It is a leading configuration based tools.
Applitools
It is one of the very popular frameworks for automated visual testing. This tool provides an AI-powered cognitive vision. It works with your existing tools. Say it is Selenium, Cypress, Appium. It uses artificial intelligence to help you with end to end visual testing and no need to write lots off assertions at each step.
Functionize – It uses computer vision validations
Summary:
In the cutting edge competitions, applications are required to be working fine on multiple environments, mobile devices, operating systems, different screen resolutions, etc. Visual testing is equally important as functional testing.
Things are changed, expectation is to have a great UX (user experience) & not only UI (User Interface)😊
And if you want a good user experience, then visual validation testing is must – Choice is yours 😊