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Integrate SmartUI SDK with Puppeteer Tests

Welcome to the world of simplified visual testing with the SmartUI SDK.

Integrating seamlessly into your existing Puppeteer testing suite, SmartUI SDK revolutionizes the way you approach visual regression testing. Our robust solution empowers you to effortlessly capture, compare, and analyze screenshots across a multitude of browsers and resolutions, ensuring comprehensive coverage and accuracy in your visual testing endeavors.

Pre-requisites for running tests through SmartUI SDK

  • Basic understanding of Command Line Interface and Puppeteer is required.
  • Login to LambdaTest SmartUI with your credentials.

The following steps will guide you in running your first Visual Regression test on LambdaTest platform using SmartUI Puppeteer SDK integration.

Create a SmartUI Project

The first step is to create a project with the application in which we will combine all your builds run on the project. To create a SmartUI Project, follow these steps:

  1. Go to Projects page
  2. Click on the new project button
  3. Select the platform as CLI for executing your SDK tests.
  4. Add name of the project, approvers for the changes found, tags for any filter or easy navigation.
  5. Click on the Submit.

Steps to run your first test

Once you have created a SmartUI Project, you can generate screenshots by running automation scripts. Follow the below steps to successfully generate screenshots

Step 1: Create/Update your test

You can clone the sample repository to run LambdaTest automation tests with SmartUI and use the puppeteerCloud.js file present in the sdk folder.

git clone
cd smartui-puppeteer-sample/sdk

Step 2: Install the Dependencies

Install required NPM modules for LambdaTest Smart UI Puppeteer SDK in your Frontend project.

npm i @lambdatest/smartui-cli @lambdatest/puppeteer-driver puppeteer

Step 3: Configure your Project Token

Setup your project token show in the SmartUI app after, creating your project.

export PROJECT_TOKEN="123456#1234abcd-****-****-****-************"

Step 4: Create and Configure SmartUI Config

You can now configure your project configurations on using various available options to run your tests with the SmartUI integration. To generate the configuration file, please execute the following command:

npx smartui config:create .smartui.json

Once, the configuration file will be created, you will be seeing the default configuration pre-filled in the configuration file:

"web": {
"browsers": [
"viewports": [
] // Full Page screenshots are captured by default for web viewports
"mobile": {
"devices": [
"iPhone 14", //iPhone 14 viewport
"Galaxy S24" //Galaxy S24 viewport
"fullPage": true, //Full Page is true by default for mobile viewports
"orientation": "portrait" //Change to "landscape" for landscape snapshot
"waitForTimeout": 1000, //Optional (Should only be used in case lazy-loading/async components are present)
"waitForPageRender": 50000, //Optional (Should only be used in case of websites which take more than 30s to load)
"enableJavaScript": false, //Enable javascript for all the screenshots of the project
"allowedHostnames": [] //Additional hostnames to capture assets from
Advanced options in SmartUI configuration
  • For capturing fullpage or viewport screenshots, please refer to this documentation
  • For the list of available mobile viewports, please refer to this documentation
  • For more information about SmartUI config global options, please refer to this documentation.

Step 5: Adding SmartUI function to take screenshot

  • You can incorporate SmartUI into your custom Puppeteer automation test (any platform) script by adding the smartuiSnapshot function in the required segment of Puppeteer script of which we would like to take the screenshot, as shown below:
const puppeteer = require("puppeteer");
const { smartuiSnapshot } = require('@lambdatest/puppeteer-driver'); // Assuming you still want to use smartuiSnapshot locally

(async () => {
// Launch a browser instance locally
const browser = await puppeteer.launch({
headless: false, // Set to false to see the UI
args: ['--start-maximized'], // Start browser maximized, remove if not needed
const page = await browser.newPage();
await page.setViewport({ width: 1280, height: 720 }); // Set viewport size as needed

// Navigate to the desired URL
await page.goto('');

// Take a screenshot with Smart UI. Replace "LT-Home" with a relevant name for your use case
await smartuiSnapshot(page, "LT-Home");

// Close the browser
await browser.close();

Step 6: Execute the Tests on SmartUI Cloud

Execute visual regression tests on SmartUI using the following commands

npx smartui exec node puppeteerCloud.js --config .smartui.json

You may use the npx smartui --help command in case you are facing issues during the execution of SmartUI commands in the CLI.

View SmartUI Results

You have successfully integrated SmartUI SDK with your Puppeteer tests. Visit your SmartUI project to view builds and compare snapshots between different test runs.

You can see the Smart UI dashboard to view the results. This will help you identify the Mismatches from the existing Baseline build and do the required visual testing.


Arguments supported in the smartUISnapshot function

The following are the different options which are currently supported:

driver (instance)The instance of the web driver used in your tests.
"Screenshot Name" (string)Specify a name for the screenshot in your tests to match the same screenshot with the name from your baseline.
options (object)Specify one or a combination of selectors in the ignoreDOM or selectDOM objects. These selectors can be based on HTML DOM IDs, CSS classes, CSS selectors, or XPaths used by your webpage. They define elements that should be excluded from or included in the visual comparison.

Handling Dynamic Data in SmartUI SDK New

When conducting visual tests, you may encounter scenarios where certain elements within your application change between test runs. These changes might introduce inconsistencies in your test results.You can ignore / select specific element(s) to be removed from the comparison by parsing the options in the smartuiSnapshot function in the following way

This is a sample for your configuration for Puppeteer to ignore by ID
let options = {
ignoreDOM: {
id: ["ID-1", "ID-2"],
await page.goto('Required URL');
await smartuiSnapshot.smartuiSnapshot(page, "Screenshot Name", options);
This is a sample for your configuration for Puppeteer to select by ID.
let options = {
selectDOM: {
id: ["ID-1", "ID-2"],
await page.goto('Required URL');
await smartuiSnapshot.smartuiSnapshot(page, "Screenshot Name", options);

For capturing the screenshot of a specific element

You can capture screenshots of targeted elements by leveraging various locator mechanisms such as XPath, CSS ID, class, and selectors. This precision-driven approach ensures accurate and specific visual regression testing for your web application's components.

This is a sample for your configuration for Puppeteer to capture an element by ID.
let options = {
element: {
id: 'Required ID',
await page.goto('Required URL');
await smartuiSnapshot.smartuiSnapshot(page, "Screenshot Name", options);

For capturing interactive lazy loading elements

If you encounter difficulties loading interactive elements that appear on scroll in full-page screenshots, consider functionally incorporating a full-page scroll into your script before capturing the screenshot. This approach ensures the elements load first, facilitating the screenshot processing.

const puppeteer = require('puppeteer');
const { smartuiSnapshot } = require('@lambdatest/puppeteer-driver');

(async () => {
const browser = await puppeteer.launch({ headless: false }); // Launches a browser
const page = await browser.newPage(); // Opens a new page

try {
await page.goto('Required URL'); // Navigate to the required URL

// Function to scroll to the bottom of the page
async function quickScrollToBottom(lastPageWait) {
await page.evaluate(async (lastPageWait) => {
const scrollToBottom = async (lastPageWait) => {
const getScrollHeight = () => document.body.scrollHeight;
let lastHeight = await getScrollHeight();
let currentHeight = 0;

while (currentHeight < lastHeight) {
window.scrollTo(0, lastHeight);
await new Promise(resolve => setTimeout(resolve, 1000)); // Wait for the page to load more content
currentHeight = lastHeight;
lastHeight = await getScrollHeight();

if (lastPageWait) {
await new Promise(resolve => setTimeout(resolve, lastPageWait)); // Additional wait at the bottom

// Scroll back to the top after reaching the bottom
window.scrollTo(0, 0);
await new Promise(resolve => setTimeout(resolve, 1000)); // Wait for scroll to top
await scrollToBottom(lastPageWait);
}, lastPageWait);

await quickScrollToBottom(100); // Adjust the wait time as needed

// Taking a screenshot with Smart UI
await smartuiSnapshot(page, "Screenshot Name");

} finally {
await browser.close(); // Close the browser

For additional information about SmartUI APIs please explore the documentation here

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