All About Visual Regression Testing and How to Automate it in WordPress

Maintaining a consistent visual style and user experience over time is essential for any website. And, visual regression testing is an integral part of WordPress development that ensures it. 

The technique entails comparing snapshots of a website before and after updates are made to spot any visual differences that may have arisen. 

Visual regression testing aids in spotting problems including unexpected design shifts, broken graphics, and textual misalignments by zeroing in on the site’s outward appearance.

Introduction to Visual Regression Testing

In contrast to more common functional testing, which examines how a website performs in terms of its intended usage, visual regression testing is concerned solely with its outward appearance, including its layout, design, typefaces, and graphics. 

As websites grow in complexity and see more frequent updates from more people, visual regressions become more likely to occur. Inadvertently altering a website’s visual appeal is a common side effect of even seemingly modest code or content changes. 

With visual regression testing as a safety net, developers may fix bugs before they affect users. A website’s reputation, user satisfaction, and, in the end, economic results, can all benefit from a more uniform aesthetic style.

How Visual Regression Testing Works

Capturing and comparing screenshots

Screenshots of the site or individual pages are taken and compared as part of visual regression testing. First, we take a series of screenshots that serve as a snapshot of the website in its infancy. 

After those adjustments are made, another set of screenshots is taken. The baseline screenshots are compared pixel for pixel with these to spot any changes.

Handling false positives and false negatives in visual regression

When the tool incorrectly identifies an intended or inconsequential visual change, further study may be required, which could be a waste of time and resources. False negatives, on the other side, occur when the tool fails to detect a visually significant change.

It is important to set a baseline and let the testing team know about any planned visual changes in order to deal with false positives and negatives. A well-documented set of design guidelines and standards can help set expectations and cut down on false positives.

Visual Regression Testing in WordPress

WordPress is a popular CMS because it can be easily customized and has a large selection of plugins available. To guarantee the highest possible standard of WordPress-based websites and applications, developers should apply a wide range of testing strategies. Visual regression testing is just one of several types of tests that the developers can run. 

• The primary goal of functional testing is to ensure that all of the features and functions of a website work as expected. 
• The purpose of a website’s security test is to find any flaws in its defenses and fix them. 
• In performance testing, the responsiveness and speed of the site are measured under varying loads. 
• Along with these other important forms of testing, visual regression testing is fundamental to preserving WordPress sites’ aesthetic quality.

Challenges and Considerations in WordPress Visual Regression Testing

With opportunities come challenges. And you will surely face some; therefore, we have already mentioned the below problems and their solutions below. Take a look.

Responsive Design and Cross-Browser Compatibility

To ensure the website renders correctly and retains its visual appeal across different devices, visual regression testing in WordPress should include testing at different screen resolutions. 

In addition, making sure consumers have a uniform experience regardless of the browser they use, facilitating cross-browser compatibility is essential. The website must be tested extensively across a wide range of browsers and versions to reveal any visual inconsistencies.

Plugin and Theme Updates

The enormous number of available plugins and themes contribute significantly to WordPress’s flexibility. However, it’s important to remember that updating plugins and themes can result in noticeable visual changes that may affect the site’s overall appeal. 

After making changes, it’s important to do visual regression testing to ensure that the site’s aesthetic continues to reflect the original vision.

Customizations and Child Themes

Customizations are great for creating one-of-a-kind designs and features, but they might cause aesthetic inconsistencies while being coded. 

In order to detect any unintentional visual changes and guarantee they are in line with the desired visual appearance, visual regression testing must include evaluating the custom code and child themes. 

To investigate and correct any visual anomalies, testers might use focused regression tests and compare versions in version control. 

Multisite Installations

The multisite functionality of WordPress makes it possible to run a network of sites off of a single server. Visual regression testing, however, is notoriously difficult to execute in multi-site systems. 

There could be visual inconsistencies if each subsite used has a different theme, plugins, and customizations. Here are a few effective strategies for multisite visual regression testing that can manage the intricacies of these setups:

• Setting a baseline for each subsite
• Prioritizing testing of essential sections
• Using automated testing systems

Now, all that you need to do is follow the below best practices to ensure there are fewer mistakes from your end. 

• Test coverage and scenarios
• Stay on top of version control and baseline image management 
• Test maintenance and regression test suites

Automating Visual Regression Testing in WordPress

What are the Benefits of Automation?

There are many advantages to automating visual regression testing in WordPress for both developers and site owners. Here are a few you need to know:

• Developers can save time and effort involved in carrying out manual visual inspections by replacing them with automated testing. 
• Developers are freed up to take up other critical tasks.
• Automation guarantees repeatable testing throughout all stages of development. It is possible to run the same tests multiple times, which eliminates the possibility of human mistakes and yields consistent data against which one can conclude. 
• This uniformity aids in the early detection of visual regressions, allowing for quicker correction and, ultimately, a more consistent user experience. 

How to Set Up Automation for Visual Regression Testing?

Preparing the Testing Environment

Stage or development environments that mimic the production setting are recommended as hosts for automated testing. If you want reliable test results, your staging and production environments should be identical down to the configurations, plugins, and themes. In addition, it is crucial to set up all required software and dependencies.

Configuring Visual Regression Testing Tools

One of the first steps in automating WordPress is integrating the chosen visual regression testing tool. The testing tool can now communicate with the WordPress platform without any extra effort. 

Users must provide credentials or API keys, list the URLs or pages to be checked, and establish their own rules and thresholds for visual comparisons while setting up the tool. To ensure that the testing procedure is tailored to the needs of the project, it is important to investigate the tool’s customization and configuration possibilities. 

Options include playing around with viewport sizes, enabling responsive testing, and establishing rules for excluding dynamic or otherwise unimportant visual elements.

Executing Automated Visual Regression Tests

When all the pieces of the automation puzzle fit together, running automated visual regression tests is a breeze. The website’s functionality and safety can be thoroughly tested by assembling a number of test cases into a test suite. The automation tool then runs these test suites, documenting any differences between the old and new versions of the website through screenshots. 

The program examines images pixel by pixel and produces reports detailing any differences. By examining the data, designers may zero in on the exact parts of the system that need fixing. Disparities in presentation can be fixed by inspecting the source code, tweaking the stylesheets, or updating the design as required.

Key Takeaways

Visual regression tests, when run on a regular basis, allow for preventive maintenance and reduce the likelihood of any inconsistencies marring your live page post any sort of code changes.

By making use of automation and adhering to a well-defined setup process, WordPress developers may easily incorporate visual regression testing into their processes. This allows them to quickly identify and fix visual issues, keep their sites looking uniform, and provide outstanding user experiences. 

For any other doubt or query, reach out to us in the comments, and we would love to resolve each one of them.