The visual elements of a modern application constitute to be the most important characteristics that create a link between the end users and the core infrastructure. With the help of visual elements like links, forms, and other buttons, the end users can easily navigate through the application and complete their goals. So, with the help of proper visual elements, app developers can help control user retention rates and bounce rates. Various modern platforms like LambdaTest help application developers easily initiate and execute visual regression testing. Moreover, it is possible to integrate other advanced technologies like parallel test execution to improve the efficiency of the testing process further.
So, with this article, we will introduce the developers and testers to the process of visual regression testing with LambdaTest.
Visual Regression Testing
While developing an application, the app developers must guarantee the proper placement of all the user interface elements present in it. Some of the common factors that need to be considered include the display resolution, screen size, and the visual capabilities of all devices. Some of the common errors that might arise due to these factors include the misplacement of elements and complete failure of the app UI. So, with the help of visual testing, the application developers can easily sort out all of these issues. However, modern applications go through frequent updates that add new features for improving the user interactivity and simplicity. However, in certain cases, these new features can harm the functioning of the existing elements.
So, with the help of visual regression testing, the app developers can re-run the test cases to ensure that the new elements do not harm the functioning of the existing web-based elements.
Scope of Modern Test Automation
Modern automation testing aims to remove human involvement in the testing processes with the help of automated test files. These test files will supply the required parameters that will help the system to emulate human communications and interactions. With the help of test automation, it is possible to run the test cases around the clock and guarantee app stability and app interactivity. While using test automation, it is also possible to store the existing test cases and reuse them in future app development projects.
However, in the context of test automation, the testers must be aware of the initial investment charges that come with it. It will cover all the expenses from multiple plugins, libraries, and dependencies that are crucial for test automation.
LambdaTest and Its Benefits
LambdaTest is a cloud-based platform for executing automated testing on modern web apps. The benefit of the cloud platform is that it allows app developers to perform real device testing on remote servers through the Internet. This process saves the hassle and expense of setting up and maintaining a physical device lab. With LambdaTest, it is possible to run the automation test cases from Selenium, Playwright, and Cypress. With Selenium test cases, LambdaTest can execute the visual regression test files or more than 3000+ browser instances.
With LambdaTest, the App developers can generate highly accurate test reports by combining multiple results from real devices and emulation software.
Some of the major benefits of using LambdaTest for performing automated visual regression testing are as follows:
- It saves a lot of time and resources by automatically capturing and comparing the screenshots during the test case execution process.
- With the help of LambdaTest, the application developers can utilize parallel testing for initiating and executing the test cases on multiple devices and browsers at the same time.
- The user interface of LambdaTest cloud allows the app developers to quickly detect any visual inconsistencies and remove them at the early stages of the development cycle. The sophisticated algorithm of LambdaTest can detect even the slightest changes in screenshots captured during the test cases compared to the baseline images.
- While performing visual regression testing with LambdaTest, the app developers can properly collaborate with the testing and production teams to improve the efficiency of the development process.
- LambdaTest also has a support team that is always available to help the new application developers and testers. This team also provides adequate information regarding all the unique tools and features available with this platform.
- Finally, it helps to enhance the user experience and reduce customer complaints with high-quality applications.
Visual Regression Testing with LambdaTest
The process of performing visual regression testing with LambdaTest is very simple as it involves a few prerequisites and steps. They are as follows:
- Setup of LambdaTest Account:
- The first step includes the application developers navigating to the official website of LambdaTest and signing up for a new account in case they do not already have one. During the signup process, the application developers might need to purchase a new license for LambdaTest. This official license will provide the access key that will help initiate the test cases on the LambdaTest real device cloud.
Now the app developers will find the username and access token on the LambdaTest dashboard which will play a critical role in authenticating the visual regression test cases.
- Choosing the Preferred Testing Framework:
- Now the application developers have to choose a test automation framework that will help them to integrate automation testing with LambdaTest. Some of the popular testing frameworks supported by LambdaTest include Cypress, Selenium WebDriver, and many others. During this process, the app developers must remember to choose the correct framework that is compatible with the app development project. For instance, Selenium will be a perfect choice when application developers are working with web applications.
- During the testing framework setup process, the developers also have to specify their target browser, device version, and operating systems. Now let us look at a sample test case for configuring these parameters with Selenium:
const { Builder, By } = require(“selenium-webdriver”);
const { Options } = require(“selenium-webdriver/chrome”);
const { strict: assert } = require(“assert”);
async function runVisualRegressionTest() {
// Set up LambdaTest credentials
const USERNAME = “YOUR_LAMBDATEST_USERNAME”;
const ACCESS_KEY = “YOUR_LAMBDATEST_ACCESS_KEY”;
// Set up the capabilities for the browsers you want to test
const capabilities = {
platform: “Windows 10”,
browserName: “chrome”,
version: “latest”,
resolution: “1920×1080”,
build: “Visual Regression Test”,
name: “My Visual Regression Test”,
};
// Initialize WebDriver
const driver = await new Builder()
.usingServer(`https://${USERNAME}:${ACCESS_KEY}@hub.lambdatest.com/wd/hub`)
.withCapabilities(capabilities)
.build();
try {
// Navigate to your web application URL
await driver.get(“https://www.example.com”);
// Take a baseline screenshot
const baselineScreenshot = await driver.takeScreenshot();
// Perform some changes to the UI (e.g., click a button, change CSS)
// … Your code here …
// Take a comparison screenshot after changes
const comparisonScreenshot = await driver.takeScreenshot();
// Compare the screenshots using LambdaTest API
const response = await fetch(“https://api.lambdatest.com/visual-regression/”, {
method: “POST”,
headers: {
“Content-Type”: “application/json”,
“Authorization”: `Basic ${Buffer.from(`${USERNAME}:${ACCESS_KEY}`).toString(“base64”)}`,
},
body: JSON.stringify({
baseline: baselineScreenshot,
comparison: comparisonScreenshot,
}),
});
assert(response.status === 200, “Visual Regression Test failed!”);
console.log(“Visual Regression Test passed successfully!”);
} catch (error) {
console.error(“Error occurred:”, error);
} finally {
await driver.quit();
}
}
runVisualRegressionTest();
- Integration of LambdaTest API
- For performing visual regression testing, the application developers must integrate the LambdaTest API for comparing screenshots. LambdaTest provides an API endpoint for visual regression testing. This endpoint will accept 2 base-24 coded image strings for performing the comparison process.
- Execution of Visual Regression Test cases
- Now, the application developers can finally execute the automated visual regression test cases. The app developers will use the LambdaTest cloud infrastructure with the help of HTTP requests. This request must be sent to the native API with the base-64 coded screenshots.
- The LambdaTest API will analyze the screenshots captured on different browsers and devices. After this, it will compare these screenshots with the baseline reference screenshots that had been previously uploaded by the application developers to the LambdaTest API. A useful tip would be to name the test cases according to the target elements as headline help to keep track of all the test cases in complex applications.
- After running the test cases, the native environment of LambdaTest will automatically generate the test cases. It will also maintain an activity log for keeping records of all the failed and successful test cases.
- Test Result Analysis
- Now all that is left is for the application developers to go through the comparison results that will be generated by the LambdaTest API. These results will also indicate whether there are any visual differences between both the screenshots that were uploaded to the API. These screenshots will also help the developers easily locate the elements that might be faulty in the visual UI of the app.
- LambdaTest provides additional features like AI-powered visual testing and integration with popular bug-tracking systems. With the help of these features, the application developers can further uplift the quality of the testing and debugging process. It is also possible for the application developers to integrate continuous development and continuous integration with the test bench. With this process, it is possible to simultaneously conduct the development and testing processes.
In this regard, we would advise the application developers to re-run the test cases a couple of times to ensure that the framework of the application is devoid of all bugs and errors. After this, the app developers can forward the application to the production phase. It is also important to re-run the visual regression test cases after any update to the core UI of the app. It is also advisable to create a test plan before proceeding with the application development process. This plan will consist of all the steps, tools, and backups that will be useful during the execution phase.
Finally, the application developers need to go through the official documentation of LambdaTest and their preferred automation testing framework. It will provide them with ample information, features, and sample test cases for understanding certain functions that might be critical and useful depending on the requirements of their app development project.
The Conclusion
With this article, we tried to understand the basics of visual regression testing and how easy it is to perform this process with modern platforms like LamdaTest. As developers, we all can agree that the shifting standards in the application industry tend to relieve more and more on automated development practices. So, it is very important to constantly update the required knowledge regarding all the automation testing practices. The app companies can also educate their developers and testers with the help of frequent awareness campaigns and seminars. A wise idea would be to conduct market surveys to collect enough data about the target audience for customizing the application. Finally, it is very important to choose the correct automation testing tools that can complement both the developers and the project.
