Playwright Interview Question & Answers - Part 2 (Latest - Most Asked) By SLT Learning

Summary

This tutorial covers essential Playwright topics, including handling different dialog types (alert, prompt, confirm) with methods like accept and dismiss. It explains how to simulate browser window maximization using custom viewport settings, as Playwright doesn't have a direct maximize function like Selenium. The video also dives into running tests in parallel, highlighting configuration options like 'worker' for controlling parallelism and 'test.describe.parallel()' for executing blocks of tests concurrently. Key tips include managing unique contexts for parallel tests to avoid conflicts and race conditions.

Takeaways

• 😀 Handling dialogs in Playwright requires registering the 'dialog' event using 'page.on('dialog', ...)' for actions like accept and dismiss.
• 😀 To interact with dialog types in Playwright, you can use 'dialog.accept()' and 'dialog.dismiss()' for alerts, confirms, and prompts.
• 😀 Playwright does not have a direct 'maximize' function like Selenium, but you can simulate maximization by launching the browser with a custom window size.
• 😀 To maximize a browser in Playwright, you can set 'startMaximized' with 'viewport: null', and make sure 'headless: false' is set.
• 😀 Playwright tests run in parallel by default, based on configurations in 'playwright.config.ts' for different browsers.
• 😀 You can control parallelism by specifying the number of workers in the config file or dynamically using the command line (e.g., 'npx playwright test --workers 3').
• 😀 To run tests in parallel in Playwright, you can use 'test.describe.parallel()' to group tests for parallel execution.
• 😀 If parallel tests are causing race conditions, avoid conflicts by creating unique browser contexts for each test.
• 😀 The 'test.describe.parallel' method allows running multiple tests concurrently, improving the speed and efficiency of test execution.
• 😀 Playwright enables dynamic management of parallelism both through configuration files and command line arguments, providing flexibility in test execution.
• 😀 Always ensure that the 'viewport' is null and the browser is non-headless ('headless: false') to properly use the 'startMaximized' functionality in Playwright.

Q & A

How can you handle dialog boxes in Playwright?

In Playwright, dialog boxes can be handled by registering an event listener for the 'dialog' event. Once the dialog appears, you can use methods such as `dialog.accept()` to accept the dialog or `dialog.dismiss()` to dismiss it. Always ensure that the event listener is set up before triggering the dialog.

Is there a direct command in Playwright to maximize the browser window?

No, Playwright does not have a direct command like Selenium's `browser.maximize()`. However, you can simulate maximizing the browser by launching it with a custom window size, setting the viewport to null, and ensuring the browser is not in headless mode (i.e., `headless = false`).

How can you set up the browser window size in Playwright?

You can set the browser window size in Playwright by using the `viewport` argument when launching the browser. To set a specific window size, you can provide the width and height in the `viewport` property, or set it to null if you want to rely on the browser's default size.

What are the prerequisites for using the `startMaximize` argument in Playwright?

To use the `startMaximize` argument in Playwright, you must set the `headless` option to `false` and set the `viewport` to `null`. This ensures that the browser window is launched in non-headless mode and can be maximized.

What is the role of the `worker` configuration in Playwright?

The `worker` configuration in Playwright defines how many browser instances (or workers) are run in parallel during test execution. You can control the number of parallel workers either by specifying it in the `playwright.config.ts` file or by using the command line option, e.g., `npx playwright test --worker=3` to run three browser instances concurrently.

How do you run tests in parallel in Playwright?

Tests in Playwright run in parallel by default when multiple browser configurations are defined in `playwright.config.ts`. You can control the number of parallel tests using the `worker` setting, or you can specify `test.describe.parallel` to run specific test cases concurrently.

What is the purpose of `test.describe.parallel` in Playwright?

`test.describe.parallel` is used to define a block of tests that will be executed concurrently. This is useful when you want to group certain tests together and run them in parallel, thereby improving test execution speed.

How can you avoid race conditions when running tests in parallel in Playwright?

To avoid race conditions when running tests in parallel, ensure that each test has its own unique browser context. This can be done by creating a new browser context for each test, which isolates the tests from each other and prevents conflicts.

How can you configure parallel test execution through the command line in Playwright?

Parallel test execution can be controlled via the command line by using the `--worker` flag. For example, running `npx playwright test --worker=3` will execute the tests using three parallel browser instances.

What steps should be followed to control parallelism in Playwright?

To control parallelism in Playwright, you can either set the `worker` configuration in the `playwright.config.ts` file or use `test.describe.parallel` to define parallel test blocks. Additionally, when using the command line, you can specify the number of workers using the `--worker` flag, such as `npx playwright test --worker=3`.