Introduction:

The Playwright is a highly robust and efficient testing framework specifically designed to streamline the automation of web application tests. As an open-source tool, it offers developers the flexibility to utilize its capabilities without incurring any licensing fees. With Playwright, developers can run tests seamlessly on a variety of browsers, including popular ones like Chrome, Firefox, and Safari. This comprehensive browser support empowers developers to conduct thorough testing across a diverse range of platforms, ensuring their applications function flawlessly and maintain compatibility across different browser environments.

One of the standout features of Playwright lies in its intuitive and user-friendly API. The framework provides a straightforward and well-documented interface that simplifies the process of interacting with web pages and their elements. Whether it's buttons, links, forms, or other essential components, Playwright's API offers a seamless way to navigate, manipulate, and validate web pages during the testing process. This level of simplicity and ease of use empowers developers to efficiently create and execute automated tests, saving valuable time and effort in the testing lifecycle.

What is Playwright?

The Playwright is an open-source test automation framework that utilizes JavaScript. It was developed and maintained by Microsoft. It provides developers with a comprehensive solution for cross-browser automation, allowing them to test web applications across a range of popular browsers. Supported browsers include Chromium-based ones like Google Chrome and Microsoft Edge, as well as Mozilla Firefox and Apple Safari. Playwright achieves this through a unified and high-level API, simplifying the testing process.

Useful tips for writing a successful Playwright test

1. Use of locators

• When you utilize the locator, you gain access to powerful features such as the auto-wait functionality and the ability to retry actions. The auto-wait feature automatically waits for the element to be available, eliminating the need for manual wait statements in your test scripts. This helps ensure that your tests are executed accurately and efficiently.
• Furthermore, the locator remains up-to-date even if the DOM structure of the web page changes. This means that your tests will continue to target the correct elements, regardless of any modifications to the page's structure. This enhances the stability and reliability of your tests, reducing the chances of encountering flaky or unreliable results.
• By leveraging the power of the locator, you not only enhance the overall efficiency and effectiveness of your tests but also significantly reduce the occurrence of flaky tests. This, in turn, boosts your confidence in the reliability of your test suite and contributes to the overall quality of your software.

2. Auto-wait

• The auto-wait feature in Playwright simplifies your test code by automatically handling element availability and readiness. It ensures that before performing actions like clicking, filling, or hovering, the element is in a state where these actions can be successfully executed. If the element is not immediately available, Playwright will wait for it to become available within the specified timeout.
• Previously, without utilizing this feature, tests may have been written with unnecessary assertions to check the state of elements before interacting with them. However, with the auto-wait feature, relying on Playwright's built-in mechanism becomes the recommended approach.
• By leveraging the auto-wait feature, you not only make your tests more concise and readable, but you also avoid potential reliability issues in scenarios such as filling in a field. Playwright's auto-wait nature handles the heavy lifting, ensuring that your tests wait for the right conditions before executing actions on elements.

3. Using ‘locator.waitFor’

When working with Playwright, there are various ‘waitFor’ methods available in Playwright 4 that can be highly useful in different scenarios. The  ‘locator.waitFor’ is particularly reliable when there is a visual indicator present.

When creating a user, we send a POST request to this endpoint. Similarly, when retrieving user information, we send a GET request to the same endpoint. If we need to constantly fetch user information within this form or if there is global state management that frequently utilizes this endpoint, Playwright may become confused.

To address this potential flakiness, it is recommended to rely on a visual indicator and use ‘locator.waitFor’ to wait for the indicator to appear on the screen. This ensures a more stable test execution.

4. Blocking unnecessary requests

Optimizing the efficiency and speed of your test suite involves the crucial step of blocking unnecessary requests. As your test suite expands, it becomes increasingly challenging to ensure that your tests solely focus on the essential resources of a page.

A typical example of such unnecessary requests includes loading non-essential resources like images, fonts, or advertisements that are not vital for testing the functionality of a page. These additional resources can significantly slow down your tests, resulting in longer test times and decreased productivity.

Thankfully, Playwright offers a simple solution to address this issue. By utilizing the page.route method, you can intercept and modify network requests made by a page during testing. This enables you to block any requests that might impede your tests, ensuring that only necessary resources are loaded.

To employ page.route, you can define a callback function that executes each network request initiated by the page. Within this function, you have access to the request's URL, method, headers, and other properties, allowing you to determine whether it should be blocked or modified. For instance, you can utilize the request.abort method to cancel a request or utilize request.fulfill to modify its response.

By blocking unnecessary requests, you can significantly reduce the execution time of your tests, enhancing the overall efficiency and productivity of your test suite.

5. Web first-assertions

The concept of "web-first assertions" in Playwright refers to assertions that are specifically designed for web applications. While you may be using a headless browser for testing, Playwright's web-first assertions offer more functionality than traditional methods like isEqual or isGreaterThan found in other testing libraries.

These assertions, combined with the power of Playwright's expect library, provide methods tailored for interacting with the DOM. These assertions, such as toHaveClass, toBeVisible, and toBeEditable, simplify UI testing by incorporating the capabilities of Jest's expect library with DOM-specific methods.

One interesting aspect of Playwright's web-first assertions is that they are asynchronous. This means they act as "async matchers" and wait for a specific condition to be met. If the condition is not met within a specified timeout, an error is thrown. While this asynchronous behavior may seem insignificant at first, it eliminates the need for multiple waitFor statements.

Playwright's web-first assertions represent conditions in a time range rather than a single moment. What's noteworthy is that there are no explicit waitFor statements. Each assertion is asynchronous and waits until the condition is met. This streamlined approach to writing asynchronous UI test code is truly remarkable and improves the efficiency of testing workflows.

Limitations of Playwright

• The playwright is a dynamic testing framework that is actively evolving, with its development team constantly working to enhance its capabilities and address any limitations. This commitment to improvement ensures that Playwright remains a powerful tool in the testing ecosystem.
• However, being a relatively new framework, Playwright may have limitations in terms of community support compared to more established testing frameworks. Users might encounter a smaller pool of community resources, discussions, and plugins compared to widely adopted tools. This could mean fewer readily available solutions and examples when encountering specific challenges.
• Furthermore, Playwright's current version does not natively support testing of native mobile applications. This can limit its usability for projects that require exclusive testing of mobile apps. For comprehensive mobile testing, users might need to consider alternative tools or explore workarounds with Playwright.
• Given the relatively limited community resources, users may find themselves relying more on official documentation and resources provided directly by the Playwright team. This reliance on official sources can be a double-edged sword, as it ensures accurate and up-to-date information but may lack the diverse perspectives and experiences offered by a larger community.
• Despite these limitations, Playwright's active development and commitment to improvement give confidence that these concerns will be addressed in future updates. As the framework gains more traction and community support grows, it is expected that these limitations will be mitigated, making Playwright an even more powerful and comprehensive testing solution.
• The playwright does not offer support for Internet Explorer 11. While this may not be a concern for many, it could be problematic for users who still rely on this browser for their testing needs. Organizations that have a significant user base on Internet Explorer 11 may find this limitation inhibiting.

LambdaTest is a cloud-based digital experience testing platform for cross-browser testing that offers a diverse selection of browser versions, including older ones like Internet Explorer, catering to the testing needs of Playwright scripts.

With its cloud-based automation testing infrastructure, LambdaTest enables rapid and seamless scaling of testing capabilities, which is especially advantageous for testing extensive and intricate applications. By integrating LambdaTest with Playwright, users can harness the combined strengths of both platforms, leading to more comprehensive and dependable testing results.

Conclusion

By following these recommendations, developers can significantly improve the effectiveness and efficiency of their Playwright scripts. Thoroughly planning tests before implementation helps in identifying the desired test scenarios and ensures that the tests cover all critical functionalities.

Avoiding hardcoded values and utilizing variables or constants allows for easy modification of test data and improves script flexibility. Employing wait conditions, such as using Playwright's built-in waiting for mechanisms or custom wait functions, ensures that tests wait for specific conditions to be met before proceeding, making them more reliable and resistant to timing issues.

By adhering to these practices, developers can create successful and maintainable Playwright scripts, leading to improved test coverage, reduced test maintenance effort, and enhanced collaboration within the development team.