If you are reading this article, then you must be familiar with automated testing and its benefits.
Automated testing has become an integral part of the testing process, and rightly so, as it gives an accurate outcome in half the time, no matter how many times you decide to run your tests. This is a huge advantage over manual testing, which is prone to human errors and incomplete test coverage due to time crunches.
The market these days provides many test automation frameworks, each with its own strengths and limitations. Playwright is one of them, a powerful test automation tool that has gained popularity. Let’s look at the offerings of this framework and where it is best suited.
What is Playwright?
Playwright is a free and open-source automation library for end-to-end testing. Backed by Microsoft, it enables developers and testers to automate interactions with a web browser. Playwright’s comprehensive feature set makes it suitable for a wide range of web testing scenarios, from simple page interactions to complex, stateful applications, including single-page applications (SPAs) and progressive web applications (PWAs).
Features of Playwright
Here is a list of features that make Playwright an excellent choice for automated testing.
- Cross-browser support: Playwright works with multiple browsers, including Chromium (Chrome, Edge), Firefox, and WebKit (Safari). This cross-browser compatibility allows consistent testing across different environments.
- Cross-platform support: You can use Playwright to test applications across multiple platforms like mobile (Android), web, and desktop (MacOS, Linux, Windows).
- Mobile emulation: Playwright can emulate mobile devices, including their geolocation, screen size, and other device-specific characteristics.
- Headless and GUI modes: It can run browsers in headless mode (without a graphical user interface) for faster execution in test environments and in GUI mode for development and debugging.
Automation capabilities: Using Playwright, you can automate a wide range of browser interactions, such as clicking buttons, filling out forms, and navigating between pages. It’s capable of handling both traditional multi-page applications and complex single-page applications along with:
- Frame handling: Web applications often use iframes to embed external content or isolate parts of the page. Playwright can seamlessly enter and interact with content within these frames, essential for testing applications that rely on iframes.
- Shadow DOM piercing: Modern web development often uses Shadow DOM to encapsulate parts of a web component’s functionality and styling. Playwright’s selectors can ‘pierce’ through the Shadow DOM, allowing it to interact with and test elements inside these encapsulated parts of the page.
- Auto-wait for elements: Playwright automatically waits for elements to be ready before performing actions, reducing flakiness and eliminating the need for manual waits.
- Tracing mechanism: You can set up test retry strategies and capture execution traces, screenshots, and videos to ensure no flakey tests.
- Web-first assertions: With Playwright, you can also automate tests for tricky dynamic web pages. The framework has a check and retry mechanism that meets the necessary conditions.
- Playwright runs out-of-process: Unlike some older testing frameworks that run their test scripts in the same process as the web content they are testing (in-process), Playwright operates out-of-process. This means that Playwright interacts with the browser at a process level, not within the context of the web page it is testing. This has its benefits like stability, reliability, no interference with web content, and better performance.
Test multiple everything: Using Playwright, you can test:
- Multiple tabs: Playwright can control and automate actions across multiple browser tabs within the same test. This is useful for testing workflows that require interactions across different tabs.
- Multiple origins: It can test scenarios involving multiple websites or domains (origins). This is important for applications that integrate or interact with various third-party services or different parts of a larger ecosystem.
- Multiple users: Playwright can simulate different user environments within the same test. Using different browser contexts can mimic multiple users with different sessions, cookies, and local storage, enabling testing of multi-user scenarios like chat applications or collaborative platforms.
Trusted events: This framework allows creating events that are:
- Real browser input: Playwright generates events that are indistinguishable from those created by real users. This includes nuanced interactions like hovering, clicking, typing, and other dynamic controls.
- Dynamic controls interaction: It can interact with complex and dynamic web elements that change in response to user actions, ensuring that automated tests behave as close to real user interactions as possible.
- Indistinguishability: The events generated by Playwright are ‘trusted’, meaning browsers recognize them as genuine user actions rather than synthetic events generated by scripts. This is crucial for testing features that respond differently to user-generated and script-generated events.
- Parallel test execution: It supports running tests in parallel, speeding up the test execution process.
- Rich context and isolation: It offers browser context functionality, allowing each test to run in an isolated environment, which helps test multi-session scenarios like user logins.
- CI testing: You can integrate Playwright with other tools and frameworks that provide CI environments. Through this, you can achieve continuous testing.
- Accessibility testing: It includes tools for testing web accessibility, helping ensure that web applications are usable by people with disabilities.
- API testing: You can use Playwright to test your application’s REST API and server-side APIs.
- Network Interception and Mocking: It allows intercepting network requests, allowing testers to stub or modify network traffic for testing different scenarios.
- Record-and-playback using Codegen: Playwright has a tool that can generate test scripts by observing your interactions with the browser.
- Visual comparisons: You can capture screenshots and compare them to achieve visual regression testing.
Getting Started with Playwright
Using Playwright is easy. You can use the following methods to get started.
Node.js: Ensure you have Node.js installed on your system. Playwright requires Node.js version 12 or higher.
You can go via two methods – the first is directly installing through your command line, and the other is through Visual Studio. If you opt for the latter, having Visual Studio Code (VSCode) on your PC is a prerequisite.
Method 1: Using the command line
- Create a project directory: Organize your project files in a proper directory system.
- Initialize a Node.js Project: Run npm init -y to create a package.json file. This step is essential for managing your project’s dependencies.
- Install Playwright: Run npm init playwright@latest. This command installs Playwright and its browser binaries (Chromium, Firefox, and WebKit) as a development dependency in your project.
Method 2: Using VSCode
- Install Playwright: Open VSCode and install Playwright from the marketplace or the extensions tab.
- Setup Playwright: Once installation is complete, paste Install Playwright in the command panel.
Once the installation is done through either method, you will find that the browsers and certain other files have been downloaded. You can add configurations in the ‘playwright.config’ file, and dependencies should be added to the ‘package.json’ file. You will also see a ‘tests’ folder that contains a basic sample test to help you get started.
Playwright has much to offer and can be a boon in the following situations.
- Cross-browser testing: If you need to ensure that your web application works seamlessly across multiple browsers (Chrome, Firefox, Safari), Playwright is an excellent choice due to its cross-browser support.
- End-to-end testing: It is excellent for end-to-end testing, simulating real user scenarios from navigating pages to interacting with elements and handling asynchronous operations.
- Automated regression testing: Playwright’s automated tests can be integrated into your CI/CD pipeline to check that new code has not broken existing functionality.
- Testing in different environments: If you need to test your application in various environments (different OSs, mobile, tablet), Playwright supports this with its device emulation capabilities.
- Complex interaction testing: Playwright excels in testing complex user interactions like drag-and-drop, hovers, and dynamic content.
- Parallel testing for faster execution: If your testing strategy requires running multiple tests simultaneously to reduce execution time, Playwright’s parallel testing capabilities are going to prove beneficial.
- Good test performance: Playwright offers exceptional performance in test execution as it takes care of the problems that lead to flakey tests.
- Capture execution trace: If you need a thorough track of executed tests, then use Playwright.
As great as Playwright is, there are some scenarios where this framework may not be the right fit.
- Non-web applications: Playwright is specifically designed for web applications. For native desktop or native mobile application testing, other tools would be more suitable.
- Limited resources or simple projects: If you are working on a very simple web project or have limited resources, the overhead of setting up and maintaining Playwright might not be justified. In such cases, more straightforward tools or manual testing might suffice.
- Steep learning curve for non-developers: If your testing team is not comfortable with coding, the learning curve for Playwright, which requires programming knowledge, could be a barrier.
In such scenarios, codeless automation tools might be a better fit, where everyone can write test cases in plain English.
- Specific requirements for proprietary tools: In cases where specific testing needs align with a proprietary tool’s features, like specific integrations or support, Playwright might not meet those unique requirements.
- Limited need for cross-browser testing: If your application only needs to support a single browser or a specific environment, the cross-browser capabilities of Playwright might be overkill.
Playwright offers a suite of features that make it a powerful and versatile tool for automated testing of web applications. However, like any tool, it has scenarios where it excels and others where it might not be the ideal choice. Understanding when to use Playwright and when to consider alternatives is crucial for an effective testing strategy.
Choosing Playwright depends on your project’s specific needs, the skills of your testing team, and the nature of the application you are developing. It is a powerful tool for many scenarios, but assessing its fit is essential based on your testing goals and constraints.