In this article, we will explore the concept of Visual Testing, a type of software testing that focuses on observing an application's visible output, monitoring for visual bugs, and comparing it to the expected output. At Q-Pros, we adopt various methods of Visual Testing to ensure excellent results for our clients.
Visual Testing involves examining an application's interface during the production phase by developers and later by end-to-end users to validate the product in its final stages. Front-end developers ensure that the application looks good on all browsers and devices and that there are no obvious defects in appearance. However, differences in rendering methods across platforms can lead to errors that affect both appearance and functionality.
The distinct value of Visual Testing lies in its ability to identify layout and interface changes caused by a lack of compatibility. Elements such as height, width, background color, font style, font size, and position within screen coordinates can vary across platforms, leading to discrepancies. Cross-browser testing is another approach that addresses different aspects, including visual testing, and ensures the application behaves as intended across various browsers.
Visual Testing can be performed manually or automatically. Manual Visual Testing involves testing the application through observation and taking notes of any anomalies or issues. However, this approach is time-consuming and may lead to false readings due to the vast number of browser and platform combinations.
Automated Visual Testing relies on tools and software to automate the testing process and compare visual elements across different screen combinations. Tools like Selenium or Appium can help generate UI variations automatically. Snapshot Testing, a method within Automated Visual Testing, creates bitmaps of screen combinations and compares pixels to highlight any unexpected changes.
While Automated Visual Testing seems appealing, it is not perfect. Relying solely on algorithms to detect differences can lead to false positives, as rendering differences can occur due to various factors. Additionally, encountering minor visual differences doesn't always mean there are bugs, as certain operating systems or browsers may adjust CSS codes differently.
At Q-Pros, we understand the importance of Visual Testing alongside other non-functional testing methods in ensuring quality assurance. We run scripts on various scenarios, utilizing automated tools and manual checks by our team of QA experts, to ensure that applications perform well on all platform combinations. While Automated Visual Testing is valuable, we recognize the need for manual observation to ensure accurate results and a high-quality user experience.