Integrating Playwright with Jest for Seamless Testing

In the modern competitive software development environment, it is critical to ensure the stability and reliability of web apps. By comprehensively testing all the elements present in modern applications, the developers can seamlessly achieve this goal during this process, they have to use advanced testing processes like automation testing and also integrate powerful testing frameworks.

Playwright is one of the most popular names in the segment of automation testing tools. Using this open-source tool, the developers can easily initiate automation test cases on multiple applications. It also provides support for various advanced test cases like performance testing, cross-browser testing, and compatibility testing.

So, with this article, we are going to explore the integration of Playwright with Jest. By combining two of these tools, the testers can ensure a seamless testing experience for modern web applications. We will also understand some of the best practices that can help modern developers and testers utilize the full potential of their testing environment.

Introducing Jest and Playwright

Playwright is a versatile and modern automation library that helps execute automated test cases on web apps across multiple browsers. This tool is completely developed and maintained by Microsoft. While using Playwright, the developers can access a set of multiple features including headless execution, cross-browser testing, and also support for multiple programming languages. Some of the commonly supported programming languages include JavaScript, Python, and TypeScript.

Playwright also has a dedicated API that allows the testers to simulate user interactions, perform assertions, and easily navigate through the web pages. The main objective of this process is to create an ideal choice for executing end-to-end testing.

On the other hand, Jest is an attractive JavaScript testing framework that focuses on ease of use and simplicity. This tool is created and maintained by Facebook. Jest is widely adopted in the JavaScript community for executing unit testing and integration testing. It provides an intuitive syntax for powerful assertion capabilities and a built-in test runner.

Jest also assures code quality and reliability with features like parallel test execution and snapshot testing.

Reasons for Integrating Playwright with Jest

Although Jest and Playwright are highly powerful testing tools when used individually, the developers can massively boost their usability by integrating them. Let us go through some of the major reasons that justify integrating Jest with Playwright:

  • Unifying the Testing Ecosystem

By combining Playwright and Jest, developers can execute not only end-to-end testing but also unit testing and integration testing. This helps to maintain a cohesive testing environment without relying on multiple tools during various stages of the application development life cycle.

  • Simplifying the Testing Configuration

The integration of Playwright and Jest is a simple process as it does not require complex configuration and setup procedures. Therefore, the testers can shift their focus to writing the test cases rather than going through the learning curve for setting up the testing infrastructure.

  • Efficiently Executing the Test Cases

The parallel testing capabilities of Jest can be used for running the Playwright test cases concurrently on multiple operating systems and device combinations. Using this approach, the testers and developers can wrap up the entire test suite in just a few days.

  • Integrating Comprehensive Test Reporting

While using Jest, the developers can access detailed test reports and cover report summaries natively. Using this feature, they can gain insightful information about test results and identify potential issues quickly. These test reports also allow the developers to quickly navigate through the application infrastructure and find the faulty elements.

Setting Up the Testing Environment

To simplify the knowledge about integrating Playwright with Jest, we have mentioned all the required steps in the correct chronological order for the new developers and testers:

  1. Step 1: Installing the Dependencies

The first step in this process involves downloading Playwright and Jest along with all the necessary dependencies using the npm package installer. For this process, the testers have to enter the following command in the terminal window.

npm install playwright @jest/testsequencer @jest/reporters

We want to caution the developers and testers to download all the required dependencies from the official websites to avoid any instances of malicious attacks or security concerns.

  1. Step 2: Configuring Jest

The next step involves configuring the project’s Jest configuration file (‘Jest.config.js’) to the root directory. During this process, the testers also have to specify Playwright as the testing environment for the execution process.

In the above code snippet, we are using the ‘Jest-Playwright-preset’ package to configure Jest to work with Playwright. Moreover, we also have to specify the directory where the test case is allocated and also information about all the setup files that need to be executed for running the test cases.

  1. Step 3: Writing The Automation Testing Scripts

Now, it is finally time for the testers to create the automation test scripts using Playwright within Jest test files (*.spec.js). After creating the test script, the testers must name it according to the target elements to avoid any confusion. To simplify this information, we have mentioned a code snippet for a sample test case that will verify the title of a web page:

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In the above reference, we are using the Playwright’s ‘page’ object for navigating to a web page and retrieving its title information. After this, we use Jest’s ‘expect’ function to assess whether the title matches the expected value as set in the testing capabilities.

  1. Step 4: Executing The Test Scripts

The final step in this process involves executing the test cases using Playwright. To begin the execution process, the testers have to enter the following command in the testing environment:

npx jest

After this, Jest will automatically launch the specified browser instances and execute the Playwright test cases. After the execution process, it will generate a detailed test report showing the status of the test script and any issues that have been detected during this process.

Best Practices and Tips for Integrating Playwright with Jest

To utilize the full potential of the integration between Jest and Playwright, the testers and developers must deploy certain practices:

  • Implementing Descriptive Test Names

Since modern applications consist of thousands of different elements, the developers have to create multiple testing instances. So, to avoid any confusion, it is a good practice to write clear and descriptive test names. It will also help them to keep track of the test cases and improve the readability and maintainability of the entire test suite.

  • Grouping the Related Tests

The developers must organize the test scripts into logical groups using Jest’s native describe function. This approach will help them to enhance the test structure and organization. Properly organizing the test scripts will also allow the non-technical members of the app-developing company to keep track of the testing status.  

  • Mocking the External Dependencies

The automation testers must utilize Jest’s native mocking capabilities for simulating external dependencies such as API calls or browser events. This approach will ensure isolated deterministic test cases. So, it has a crucial role in elevating the dependency and accuracy of the final Test reports.

  • Handling the Test Setup and Teardown Process

Jest provides various native hooks for setting up and tearing down test fixtures. Some of the common instances include ‘beforeAll’, ‘afterAll’, ‘afterEach’, and ‘beforeEach’. Using these hooks, the testers can also create and destroy browser instances as per the requirements of their application development project.

  • Integrating Cloud Testing

Using Playwright, the testers can execute cross-browser testing on the applications to verify their stability on multiple devices, operating systems, and browser versions. However real device testing is an important component of effective cloud testing. Therefore, the developers can achieve this goal by running the test cases on thousands of browsers and real devices through cloud servers.

Modern AI-powered test orchestration and execution platforms like LambdaTest also allow developers to execute the Playwright test cases on more than 50 different browsers and operating systems at the same time. It also has additional features like artificial intelligence to properly arrange the test cases and execute them on the respective web elements. Finally, it elevates test reporting and debugging with comprehensive test reports and live activity logs.

  • Monitoring the Test Coverage

Since modern applications consist of multiple different elements, it is a crucial process to ensure that there is a test instance to verify the functioning of all these elements. So, we advise the testers to regularly monitor test coverage using Jest’s building coverage reports and identify areas of code that require additional testing.

It is also worth mentioning that the developers must run this process after every subsequent update to ensure that there are tests added to verify the functioning of all the new elements within the application infrastructure.

  • Using the Potential Of Parallel Testing

As we already mentioned earlier, individual testing would take several months to complete the entire testing phase as there are thousands of different testing instances. So, by using parallel testing, the developers can run thousands of different testing instances on multiple configurations and machines at the same time. Jest provides a parallel test execution feature to run Playwright tests concurrently.

Moreover, while using cloud platforms like LambdaTest, the testers can also use the remote servers to execute automated cross-browser testing in a parallel configuration with Playwright and Jest.

  • Going through the Documentation

Although we have mentioned the basic setup process and some of the most important practices in this article, we advise the developers to go through the official documentation of Jest and Playwright. This documentation will provide critical information about various methods, functions, and features that might be useful depending on the individual test cases.

Moreover, Playwright explains the functioning of all its methods using sample test cases to ensure ease of understanding. We also advise the developers and testers to join the open-source community of Playwright as it is filled with enthusiastic developers and testers who are always ready to help newcomers.

The Bottom Line

Conclusively, we can say that integrating Playwright with Jest offers a powerful solution for testing modern web apps with efficiency and ease. By combining Playwright’s robust automation capabilities with Jest’s intuitive testing framework, the developers can verify the stability and reliability of modern web apps. This process also helps guarantee a streamlined testing workflow.

This approach also requires minimal configuration and setup process to ensure a seamless testing experience. This, in turn, allows teams to improve their focus on delivering high-quality software products. So, whether the testers are testing complex user interfaces or validating user interface components, the combination of Jest and Playwright allows them to write comprehensive test cases that inspire confidence in the functionality of the web app.