Playwright: automation testing for modern web applications

In this article, you’ll learn more about Playwright, a tool developed by Microsoft. We will look at its use, key benefits and compare it with other automation tools such as Cypress, Selenium, etc. In addition, we will introduce you to “best practices” for successful deployment of Playwright in your project.

What is a Playwright?

Playwright is an open-source tool that provides a unified API for controlling browsers such as Chromium, Firefox, and WebKit. Playwright features high performance, reliability and a rich feature set that simplifies test automation and interaction with browsers. With its ability to simulate real-world user scenarios and provide access to browser objects, Playwright is becoming an indispensable tool for developers focused on creating and testing quality web applications.

Benefits of using Playwright

Playwright brings a number of benefits for developers and testers. Here are the main benefits of using it:

1. Multi-browser support

One of Playwright’s biggest advantages is its support for multiple browsers, including Chromium, Firefox, and WebKit. This means that you can write tests once and then run them on different browsers without having to change your test code. This flexibility allows you to test your web application on different platforms, while making sure it is compatible with different browsers.

2. Speed and efficiency

Playwright is designed to be fast and efficient. Thanks to its optimizations and parallel test execution, it can significantly reduce the time required to execute a test cycle. It also provides ways to quickly interact with the browser and manipulate its various components, which contributes to faster writing and running tests.

3. Flexibility of language choice

Playwright supports multiple programming languages, including JavaScript, Python, and TypeScript. So you can write tests in your preferred language and take advantage of its benefits and functionalities. This flexibility allows developers and testers to work with the tool they feel most comfortable with and have the most expertise in.

4. Advanced features

Playwright brings a number of advanced features that make it easier to test and automate browsers. These include capabilities such as mobile device simulation, screen recording, network emulation and more. These functionalities are very useful for responsiveness testing, bug detection and getting trustworthy results.

5. Broad community support

Playwright has a rapidly growing community of developers and testers who actively contribute to its development. There are plenty of resources, documentation, tutorials and examples available to help you use and master Playwright. In addition, the community regularly releases updates and bug fixes, contributing to improving and extending its functionality.

6. Integration with existing tools

Playwright is able to integrate with existing tools and frameworks, thus enabling easy implementation of automation into the existing development ecosystem. Playwright supports libraries and interfaces for a variety of popular frameworks such as Jest, Mocha and TestCafe, making it easy to integrate with your existing tools and processes.

Playwright vs Selenium

The comparison between Playwright and Selenium is important because they are two popular browser automation tools. Both technologies provide the ability to automate web application testing, but there are some key differences between them. Here is a comparison of Playwright and Selenium in several aspects:

Browser support:

  • Playwright: Playwright offers a unified API for multiple browsers including Chromium, Firefox and WebKit.
  • Selenium: Selenium is based on the WebDriver architecture, which allows you to automate different browsers. However, browser support is not as uniform and some browsers may require appropriate drivers.

Language support:

  • Playwright: Playwright is available for multiple programming languages, including JavaScript, Python, and TypeScript, allowing developers to work in their preferred language.
  • Selenium: Selenium is also available in a variety of languages, including Java, Python, Ruby, C#, etc.

Architecture:

  • Playwright: offers a modern and fast architecture that allows running tests on multiple browsers in parallel.
  • Selenium: Its architecture requires a specific driver for each web browser, which can be difficult and limiting.

Features and functionalities:

  • Playwright: Playwright brings a host of advanced browser automation features, including support for mobile devices, screen recording and network emulation. It also offers various tools for quick debugging and test management.
  • Selenium: Selenium is a robust and proven tool, but it may not have all the advanced functionality available in Playwright.

Documentation and support:

  • Playwright: Playwright is a relatively new tool, but it already has decent documentation and a growing community. Microsoft, the company behind the development of Playwright, provides support and releases regular updates.
  • Selenium: Selenium has been in use for a long time and has an extensive community and documentation.

Summary

If you’re looking for a modern tool with advanced functionality and a single API for multiple browsers, Playwright can be a great choice. If you prefer a proven tool with extensive experience and community, Selenium will still be a good choice.

Playwright vs cypress

We wrote about Cypress in a previous article. Here’s his comparison to Playwright.

Browser support:

  • Playwright: Playwright offers a unified API for multiple browsers including Chromium, Firefox and WebKit.
  • Cypress: Cypress is optimized to run tests in its own browser, which is built on Chromium. This means that it does not support all browsers, such as Safari.

Language support:

  • Playwright: Playwright is available for multiple programming languages, including JavaScript, Python, and TypeScript, allowing developers to work in their preferred language.
  • Cypress: Cypress primarily focuses on JavaScript support. Although some other languages can be used, such as TypeScript or CoffeeScript, the main language for writing tests in Cypress is JavaScript.

Performance:

  • Playwright: Playwright is known for its high speed and efficient test execution. Its parallel capability enables faster test execution on different browsers and devices.
  • Cypress: Cypress also boasts fast and efficient test execution, but some tests may be slower if they depend on a single browser.

Asynchronous testing:

  • Playwright: Playwright natively supports asynchronous testing, allowing you to seamlessly manage asynchronous operations and wait for web pages or elements to load.
  • Cypress: regarding asynchronous testing, its API requires special commands to manage asynchronous operations.

Flexibility:

  • Playwright: Playwright provides more flexibility in browser selection and supports testing on mobile devices.
  • Cypress: Cypress focuses on providing a more comprehensive and simpler solution with a custom browser and is not as flexible with the choice of browsers.

Summary

Playwright is suitable for those looking for advanced features, parallel test execution and multi-browser support. Cypress is ideal for those who prefer a simpler and more complete solution with recording and tuning tools.

Playwright installation

The following steps will show you how to install Playwright and set up your first project.

Step 1: Install Node.js

  • Visit the official Node.js website.
  • Download the latest stable version of Node.js for your operating system.
  • Run the Node.js installation file and follow the on-screen instructions to complete the installation.

Step 2: Install Playwright

Once you have successfully installed Node.js, you can proceed to install Playwright.

Installing Playwright using npm:

  • Open a terminal or command prompt on your computer.
  • Go to your working directory where you want Playwright installed.
  • Run the following command to install Playwright:
Installing Playwright using npm
Once the installation is complete, you can start using Playwright in your project.

Step 3: Create the first test with Playwright

Now that you have Playwright installed, you can start creating your first tests.

  • Create a new file with a .js extension for your test (e.g. js).
  • open the file in the code editor and import Playwright:

Creating the first test with Playwright

  • Create a function for your test and start using the Playwright API. For example, open a new browser window:

Create a function for your test and start using the Playwright API

  • Run your test using the tool you used to install Playwright (npm)

Run your test using the tool you used to install Playwright

Best practices when using Playwright

Playwright is a powerful browser automation tool, here are some recommendations for using it effectively:

1. Proper browser management

When automating browsers, it is important to manage the browser lifecycle effectively. It is recommended to create and close browser instances only when necessary. This helps to save memory and make tests run faster. If necessary, you can create and share browser instances between different tests or at the beginning and end of each test.

2. Optimization of waiting for loading

Optimizing the wait for a page to load or for certain events is important to avoid unreliable and unstable tests. Using proper wait methods, such as waitForLoadState or waitForSelector, helps ensure that your tests are run in the correct context.

3. Proper treatment of bugs

When automating browsers, it is important to treat bugs and unexpected situations correctly. Playwright provides methods to handle bugs such as catching exceptions with try-catch blocks, handling timeouts, or examining failed asynchronous operations.

4. Parameterization of tests

Test parameterization allows you to run the same test scenario with different inputs or settings. Playwright allows easy parameterization of tests using a switch or configuration file. This practice helps to increase test coverage and ensure that you are testing different scenarios and different combinations of inputs.

5. Use of assertions

It is important to use assertions to verify that your code is working properly and to ensure that your tests are correct. Playwright provides built-in methods to verify the state of a page or the existence of certain elements. The use of these methods, such as expect, helps in creating reliable and concise tests.

6. Sustainability and reusability

When writing tests in Playwright, it is important to pay attention to maintainability and reusability of the code. It is recommended to create clear and well-documented tests that are easy to understand and modify. It’s also a good idea to create functions and classes for reusable parts of the code, which helps reduce duplication and makes tests easier to maintain.

7. Proper logging and tracking

When writing and running tests, proper logging and tracking of events is important. Playwright provides options for recording events and logging different parts of the test. This logging helps to track and analyze the progress of tests, gather information about bugs and identify problem areas in the application.

Recommended resources

For more information about Playwright, you can visit the official website and project documentation. Here are some resources to help you gain a deeper insight into what Playwright has to offer:

  • The official website where you can find basic information about the tool, its features, uses and the latest news.
  • Documentation:Playwright provides detailed documentation that includes examples, API references, and instructions to get started with the tool.
  • GitHub repository: To check out the source code and current development projects of Playwright.
  • Microsoft Blog:Microsoft regularly contributes articles and updates about Playwright on its technology blog.
  • YouTube videos: On YouTube, you’ll find a variety of videos and tutorials to help you better understand the functionality and use of Playwright. Just search for “Playwright tutorial” or “Playwright introduction”.

Conclusion

Playwright is a powerful browser automation tool that unifies the testing of web applications on different browsers. Its simple API and multi-language support make it a popular tool among developers. With Playwright, you can write robust test scripts that ensure the quality and reliability of your web applications.

Install Playwright and start taking advantage of its benefits to automate your web application testing today!

About the author

Katarína Kučáková

Software Test Engineer

Moja cesta k testovaniu softvéru sa začala v roku 2019 až po štúdiu ekonómie a pracovných skúsenostiach v iných odvetviach. To mi pomohlo vnímať IT svet v rôznych súvislostiach. Ten totiž ponúka neustále nové výzvy, pre ktoré rada hľadám riešenia. Obľubujem oddych pri čítaní, turistiku alebo lyžovanie. LinkedIn

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