8 Tips for Effective Browser Testing Automation With Jest

Are you feeling the heat of browser testing? Ensuring your website works seamlessly across multiple browsers and devices can be daunting.

But fear not because Jest is here to save the day with its powerful browser testing automation capabilities! With Jest, you can put your browser testing on autopilot and breeze through your testing checklist with ease.

We have put together eight tips to help you optimize your browser testing automation using Jest.

Browser Testing Automation

These tips will not only help you save time but also ensure that your website is running smoothly! So sit back, relax, and let Jest do the heavy lifting for you.

1. Start with a bangin’ configuration file.

First, what is a configuration file? A configuration file is a file that specifies the settings and options that Jest should use when running your tests. This includes options like where to find your test files, which test environment to use, and which reporters to use for outputting test results.

So why is a well-crafted configuration file so important? For starters, it can save you a lot of time in the long run. Setting up your configuration file correctly ensures that Jest runs your tests consistently and efficiently without needing manual intervention.

A well-crafted configuration file can make all the difference in your testing automation journey. Set up your configuration file just right, and you’ll be blazing through your testing checklist!

Also Read: 9 Benefits of Implementing Regression Testing in Your Organization

2. Keep your Test Suites organized like a BOSS.

Doesn’t nobody have time for a messy test suite? Keep your test suites organized like a pro, and you’ll feel cool as a cucumber as you easily tackle each test case.

Here’s how you can keep your test suites organized like a boss in Jest.

A. Descriptive test suite names can help you quickly identify what each test suite is testing. Use names that are descriptive and specific to the functionality being tested.

Here’s an example:

describe(‘Authentication’, () => {

  // Test cases go here


B. Grouping related test suites can make it easier to navigate and understand your test suite. You can use the describe function to group related test suites.

Here’s an example:

describe(‘Authentication’, () => {

  describe(‘Login’, () => {

// Test cases go here


  describe(‘Logout’, () => {

// Test cases go here



describe(‘User Management’, () => {

  describe(‘Create User’, () => {

// Test cases go here


  describe(‘Update User’, () => {

// Test cases go here



C. You can use Test.only and Test.skip to focus and skip tests, respectively. This can help keep your test suites organized and ensure that only the necessary tests are run. 

Here’s an example:

describe(‘Authentication’, () => {

  describe.only(‘Login’, () => {

// Only this test suite will be run


  describe.skip(‘Logout’, () => {

// This test suite will be skipped



3. Harness the power of Parallel Testing

Running your tests sequentially? Ain’t nobody got time for that! With parallel testing, you can get your testing done in a flash and feel like a superhero.

Jest supports running tests in parallel, which can significantly speed up your test execution time. To enable parallel testing, you can set the –runInBand option to false in your Jest configuration file.

Here’s an example:

// jest.config.js

module.exports = {

  // …

  maxWorkers: 4,

  runInBand: false,

  // …


In this example, we’ve set the maxWorkers option to 4, which means Jest will run up to 4 tests in parallel.

If you have a large test suite, you can split it into smaller chunks to take advantage of parallel testing. For example, if you have 100 test cases, you can split them into 4 test suites of 25 test cases each. Then, you can run each test suite in parallel with Jest.

Cloud-based testing platforms like LambdaTest, a digital experience testing platform that allows developers and testers to run tests in parallel across multiple browsers and devices. LambdaTest provides a scalable cloud infrastructure that allows you to run tests in parallel and get results quickly.

4. Use Visual Regression Testing

Visual Regression Testing allows you to compare screenshots of your website before and after changes are made, ensuring that your website looks consistent across multiple browsers and devices.

Implementing Visual Regression Testing with Jest can be a game-changer when it comes to catching layout bugs and preventing visual regressions.

Fortunately, LambdaTest offers a solution to these challenges with their Pixel by Pixel Visual UI Regression Testing feature.

With this feature, you can compare screenshots of your website before and after changes are made and identify visual deviations related to Icon Size, Padding, Color, Layout, Text as well, Element position, and much more.

One of the challenges with traditional Visual Regression Testing is that it can be difficult to manage a large number of screenshots. LambdaTest’s Pixel by Pixel Visual UI Regression Testing feature overcomes this challenge by providing a centralized dashboard where you can view and manage all your screenshots.

Another challenge with Visual Regression Testing is analyzing the results. With LambdaTest’s Pixel by Pixel Visual UI Regression Testing feature, you can quickly identify visual deviations using their smart image-to-image comparison technology. This allows you to quickly locate the exact areas of your website that have changed and ensure that there are no visual regressions.

5. Utilize the ‘describe.each’ Method

The ‘describe.each’ Method is a powerful feature of Jest that allows you to write a single test suite that runs multiple times with different data inputs. This is useful when you have many test cases that are similar but require different data inputs. Using ‘describe.each’ can significantly reduce the number of test suites you need to write and maintain.

Let’s take an example of a function that calculates the sum of two numbers. You could write multiple test cases for this function, each with different input values. Here’s an example of how you could write these test cases using ‘describe.each’:

describe.each([ [1, 2, 3],

  [0, 0, 0],

  [-1, 2, 1],

  [2.5, 2.5, 5],

])(‘add(%i, %i)’, (a, b, expected) => {

  test(`returns ${expected}`, () => {

expect(add(a, b)).toBe(expected);



In this example, we’re using ‘describe.each’ to run the same test suite numerous times with different data inputs. The array passed to ‘describe.each’ contains arrays of input values for the ‘add’ function, as well as the expected output value. Jest will automatically run the ‘test’ function for each set of input values, making it easy to write and maintain test cases.

The output of this test suite will look something like this:

add(1, 2)

  ✓ returns 3

add(0, 0)

  ✓ returns 0

add(-1, 2)

  ✓ returns 1

add(2.5, 2.5)

  ✓ returns 5

As you can see, Jest runs the same test suite for each set of input values, making it easy to write and maintain test cases.

6. Leverage Test Coverage Analysis

Test Coverage Analysis helps you identify areas of your codebase that are not being tested. Jest provides built-in support for Test Coverage Analysis, so you can easily see which parts of your code are covered by your tests and which parts need more attention.

To enable Test Coverage Analysis in Jest, simply pass the ‘–coverage’ flag when running your tests:

jest –coverage

Jest will generate a coverage report after running your tests, which will show you the percentage of code coverage for each file in your codebase.

Additionally, LambdaTest offers integration with Jest for Test Coverage Analysis. By leveraging LambdaTest’s integration, you can generate detailed Test Coverage Analysis reports and identify areas of your codebase that need more attention. This can help you ensure your application is thoroughly tested and ready for production.

7. Embrace the magic of snapshot testing

Snapshot testing may sound like something out of a Harry Potter movie, but it’s a powerful tool for ensuring that your website looks and behaves just as it should.

This technique can be useful in detecting unexpected changes in the output of a component or page, such as changes in HTML, CSS, or JavaScript that could break functionality or alter the page’s appearance.

In Jest, snapshot testing can be implemented using the ‘toMatchSnapshot’ method. This method takes a snapshot of the output of a component or page and saves it as a file in the test directory.

On subsequent test runs, the ‘toMatchSnapshot’ method will compare the new output to the previously saved snapshot and indicate whether any changes have occurred.

Here’s an example of snapshot testing in Jest:

test(‘renders correctly’, () => {

  const component = renderer.create(<Button />);

  const tree = component.toJSON();



In the above example, we create a new instance of a ‘Button’ component and save a snapshot of its output using the ‘toMatchSnapshot’ method. On subsequent test runs, Jest will compare the new output to the saved snapshot to ensure that no unexpected changes have occurred.

One potential problem with snapshot testing is that changes to the layout or design of a page can often result in a large number of false positives, as even minor changes to the layout can cause the snapshot to fail.

This is where LambdaTest’s Intelligent Visual Regression Comparison options come in. By providing more granular control over the comparison process, these options can help reduce the number of false positives and make it easier to identify actual changes that require attention.

For example, the ‘largeImageThreshold’ option allows you to specify a threshold for ignoring small differences in image size. In contrast, the ‘ignore’ option can be used to ignore specific elements or attributes in the comparison process.

With these options, you can perform more targeted comparisons and reduce the likelihood of false positives, making it easier to identify actual changes that require attention.

8. Keep your dependencies up-to-date like a champ

As a developer, it’s essential to keep your dependencies up-to-date. Not only does this ensure that you’re using the latest and greatest tools and features, but it also helps to keep your codebase secure by patching any potential vulnerabilities.

Don’t be that developer who’s stuck in the past! Keep your dependencies up-to-date like a champ, and you’ll feel fresh and current even at a temperature of 100.

Also Read: Test Automation For Single Page Applications (SPAs) Using Python


And that’s a wrap! You now have 8 killer tips for effective browser testing automation with Jests. From configuring your setup to harnessing the power of parallel testing and using snapshot testing, you have everything you need to ensure your website is in tip-top shape.

Remember to keep your test suites organized like a boss, embrace the magic of snapshot testing, and don’t forget to leverage test coverage analysis. And if you encounter any problems along the way, don’t worry! LambdaTest is always here to help.

Now go forth and test, my fellow developers! Happy testing! But don’t forget to have a little fun while you’re at it. After all, with Jests, even testing can be an enjoyable experience.

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