Discover AI-native insights at Testμ Conference‘25

How to use handleWindowError method in Playwright Internal

Best JavaScript code snippet using playwright-internal

base.js

...73    let event = true74    while (event) {75      event = loadError.shift()76      if (event) {77        handleWindowError(event)78      }79    }80  }81  window.removeEventListener('error', window.handleLoadError, true)82}83const bindGlobalError = () => {84  window.addEventListener('error', handleWindowError, true)85  window.addEventListener('unhandledrejection', event => {86    const reason = event.reason87    reportError(reason)88  })89}90const getCntp = () => {91  return document.body.attributes['mg-stat-page'].value...

InvalidEventListeners-test.js

Source: InvalidEventListeners-test.js

...31      'Expected `onClick` listener to be a function, instead got a value of `string` type.',32    );33    spyOnProd(console, 'error');34    const uncaughtErrors = [];35    function handleWindowError(e) {36      uncaughtErrors.push(e.error);37    }38    window.addEventListener('error', handleWindowError);39    try {40      node.dispatchEvent(41        new MouseEvent('click', {42          bubbles: true,43        }),44      );45    } finally {46      window.removeEventListener('error', handleWindowError);47    }48    expect(uncaughtErrors.length).toBe(1);49    expect(uncaughtErrors[0]).toEqual(...

before.js

Source: before.js

1// A file to load before everything else, for testing modifications made before React even loads.2function captureTrace () {3	let err;4	try {5		throw Error("Capturing Trace");6	} catch (caughtErr) {7		err = caughtErr;8	}9	return err;10}11// This code listens for addEventListener calls on window12// This seems to only catch the constant error handling listeners from ReactDOM (search for `handleWindowError` and look around there to see what I mean)13let _addEventListener = window.addEventListener.bind(window);14window.addEventListener = function (...args) {15	let err = captureTrace();16	if (args[1].name !== "handleWindowError") {17		console.log('addEventListener', err, ...args);18	}19	return _addEventListener(...args);20};21window.addEventListener.toString = function () {22	console.log('[INFO] window.addEventListener.toString() called!');23	return _addEventListener.toString();24};25/*let _Map = Map;26Map = function (...args) {27	let err = captureTrace();28	//console.log("Map constructor", err, ...args);29	return new _Map(...args);30};31Map.toString = _Map.toString.bind(_Map);*/...

Using AI Code Generation

1const { chromium } = require('playwright');2(async () => {3  const browser = await chromium.launch({ headless: false });4  const context = await browser.newContext();5  const page = await context.newPage();6  await page.evaluate(() => {7    throw new Error('this is a test');8  });9  await browser.close();10})();

Using AI Code Generation

1const playwright = require('playwright');2(async () => {3  const browser = await playwright['chromium'].launch();4  const context = await browser.newContext();5  const page = await context.newPage();6  await page.evaluate(() => {7    throw new Error('Example error');8  });9  await browser.close();10})();11    at processTicksAndRejections (internal/process/task_queues.js:97:5)12    at processTicksAndRejections (internal/process/task_queues.js:97:5)

Using AI Code Generation

1const { webkit, devices } = require('playwright');2const iPhone = devices['iPhone 6'];3(async () => {4  const browser = await webkit.launch();5  const context = await browser.newContext({6    recordVideo: {7    },8  });9  const page = await context.newPage();10  await page.screenshot({ path: 'google.png' });11  await browser.close();12})();

Using AI Code Generation

1const playwright = require('playwright');2(async () => {3  for (const browserType of BROWSER) {4    const browser = await playwright[browserType].launch();5    const context = await browser.newContext();6    context._options.handleWindowError = true;7    const page = await context.newPage();8    await page.evaluate(() => {9      setTimeout(() => {10        throw new Error('this is a test error');11      }, 3000);12    });13  }14})();

Using AI Code Generation

1const playwright = require('playwright');2(async () => {3  const browser = await playwright['chromium'].launch();4  const page = await browser.newPage();5  await page.evaluate(() => {6    throw new Error('this is an error');7  });8  await browser.close();9})();10const playwright = require('playwright');11(async () => {12  const browser = await playwright['chromium'].launch();13  const page = await browser.newPage();14  await page.evaluate(() => {15    throw new Error('this is an error');16  });17  await browser.close();18})();19const playwright = require('playwright');20(async () => {21  const browser = await playwright['chromium'].launch();22  const page = await browser.newPage();23  await page.evaluate(() => {24    throw new Error('this is an error');25  });26  await browser.close();27})();28const playwright = require('playwright');29(async () => {30  const browser = await playwright['chromium'].launch();31  const page = await browser.newPage();32  await page.evaluate(() => {33    throw new Error('this is an error');34  });35  await browser.close();36})();37const playwright = require('playwright');38(async () => {39  const browser = await playwright['chromium'].launch();40  const page = await browser.newPage();41  await page.evaluate(()

Using AI Code Generation

1const { chromium } = require('playwright');2const { handleWindowError } = require('playwright/lib/internal/stackTrace');3(async () => {4  const browser = await chromium.launch();5  const context = await browser.newContext();6  const page = await context.newPage();7  page.on('pageerror', async (err) => {8    console.log(await handleWindowError(page, err));9  });10  await page.evaluate(() => { throw new Error('Error in page'); });11  await browser.close();12})();13const { chromium } = require('playwright');14const { handleRequestFailure } = require('playwright/lib/internal/stackTrace');15(async () => {16  const browser = await chromium.launch();17  const context = await browser.newContext();18  const page = await context.newPage();19  page.on('requestfailed', async (req) => {20    console.log(await handleRequestFailure(page, req));21  });22  await browser.close();23})();24const { chromium } = require('playwright');25const { handleRequestFinished } = require('playwright/lib/internal/stackTrace');26(async () => {27  const browser = await chromium.launch();28  const context = await browser.newContext();29  const page = await context.newPage();30  page.on('requestfinished', async (req) => {31    console.log(await handleRequestFinished(page, req));32  });33  await browser.close();34})();35const { chromium } = require('playwright');36const { handleRequest

Using AI Code Generation

1const { chromium } = require('playwright');2(async () => {3  const browser = await chromium.launch({ headless: false, slowMo: 50 });4  const context = await browser.newContext();5  await context.exposeFunction('onError', (error) => {6    console.log('error', error);7  });8  await context.addInitScript(() => {9    window.addEventListener('error', event => {10      window.onError(event.error);11    });12  });13  const page = await context.newPage();14  await page.evaluate(() => {15    console.log(a);16  });17  await browser.close();18})();19## Method 2: Using the `on()` method20const { chromium } = require('playwright');21(async () => {22  const browser = await chromium.launch({ headless: false, slowMo: 50 });23  const context = await browser.newContext();24  const page = await context.newPage();25  await page.on('pageerror', error => {26    console.log('error', error);27  });28  await page.evaluate(() => {29    console.log(a);30  });31  await browser.close();32})();33const { chromium } = require('playwright');34(async () => {35  const browser = await chromium.launch({ headless: false, slowMo: 50 });36  const context = await browser.newContext();37  const page = await context.newPage();38  page.on('pageerror', error => {39    console.log('error', error);40  });41  await page.evaluate(() => {42    console.log(a);43  });44  await browser.close();45})();46const { chromium } = require('playwright');

Using AI Code Generation

1const { chromium } = require('playwright');2const { InternalApi } = require('playwright/lib/internal/api');3const { handleWindowError } = require('playwright/lib/internal/handleWindowError');4(async () => {5  const browser = await chromium.launch();6  const context = await browser.newContext();7  const page = await context.newPage();8  await page.exposeFunction("__playwright__internal__handleWindowError", handleWindowError);9  await page.evaluate(() => window.addEventListener("error", event => {10    event.preventDefault();11    event.stopImmediatePropagation();12    window.__playwright__internal__handleWindowError(event.error);13  }));14  await page.click('text=Sign in');15  const error = await InternalApi.evaluateHandleInUtility(page, ({page}) => page.__error);16  console.log(await error.jsonValue());17  await browser.close();18})();19### `handleWindowError(error)`

Using AI Code Generation

1const { PlaywrightInternalError } = require('playwright-core/lib/errors');2const { handleWindowError } = new PlaywrightInternalError();3const { PlaywrightInternalError } = require('playwright-core/lib/errors');4const { handleWindowError } = new PlaywrightInternalError();5const { PlaywrightInternalError } = require('playwright-core/lib/errors');6const { handleWindowError } = new PlaywrightInternalError();7const { PlaywrightInternalError } = require('playwright-core/lib/errors');8const { handleWindowError } = new PlaywrightInternalError();9const { PlaywrightInternalError } = require('playwright-core/lib/errors');10const { handleWindowError } = new PlaywrightInternalError();11const { PlaywrightInternalError } = require('playwright-core/lib/errors');12const { handleWindowError } = new PlaywrightInternalError();13const { PlaywrightInternalError } = require('playwright-core/lib/errors');14const { handleWindowError } = new PlaywrightInternalError();15const { PlaywrightInternalError } = require('playwright-core/lib/errors');16const { handleWindowError } = new PlaywrightInternalError();17const { PlaywrightInternalError } = require('playwright-core/lib/errors');18const { handleWindowError } = new PlaywrightInternalError();19const { PlaywrightInternalError } = require('playwright-core/lib/errors');20const { handleWindowError } = new PlaywrightInternalError();21const { PlaywrightInternalError } = require('playwright-core/lib/errors');22const { handleWindowError } = new PlaywrightInternalError();23const { PlaywrightInternalError } = require('playwright

Using AI Code Generation

1const { chromium } = require("playwright");2(async () => {3  const browser = await chromium.launch({ headless: false });4  const context = await browser.newContext();5  const page = await context.newPage();6  page.on("pageerror", (err) => {7    console.log("error", err);8  });9  await page.click("#fake");10  await browser.close();11})();

StackOverFlow community discussions

Questions

Discussion

Running Playwright in Azure Function

Is it possible to get the selector from a locator object in playwright?

firefox browser does not start in playwright

Jest + Playwright - Test callbacks of event-based DOM library

How to run a list of test suites in a single file concurrently in jest?

firefox browser does not start in playwright

I played with your example for a while and I got the same errors. These are the things I found that made my example work:

It must be Linux. I know that you mentioned that you picked a Linux plan. But I found that in VS Code that part is hidden, and on the Web the default is Windows. This is important because only the Linux plan runs npm install on the server.

Make sure that you are building on the server. You can find this option in the VS Code Settings:

Make sure you set the environment variable PLAYWRIGHT_BROWSERS_PATH, before making the publish.

https://stackoverflow.com/questions/63949978/running-playwright-in-azure-function

Well this is one way, but not sure if it will work for all possible locators!.

// Get a selector from a playwright locator
import { Locator } from "@playwright/test";
export function extractSelector(locator: Locator) {
    const selector = locator.toString();
    const parts = selector.split("@");
    if (parts.length !== 2) { throw Error("extractSelector: susupect that this is not a locator"); }
    if (parts[0] !== "Locator") { throw Error("extractSelector: did not find locator"); }
    return parts[1];
}

https://stackoverflow.com/questions/72044959/is-it-possible-to-get-the-selector-from-a-locator-object-in-playwright

I found the error. It was because of some missing libraries need. I discovered this when I downgraded playwright to version 1.9 and ran the the code then this was the error msg:

(node:12876) UnhandledPromiseRejectionWarning: browserType.launch: Host system is missing dependencies!

Some of the Universal C Runtime files cannot be found on the system. You can fix
that by installing Microsoft Visual C++ Redistributable for Visual Studio from:
https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads

Full list of missing libraries:
    vcruntime140.dll
    msvcp140.dll
Error
    at Object.captureStackTrace (D:\Projects\snkrs-play\node_modules\playwright\lib\utils\stackTrace.js:48:19)
    at Connection.sendMessageToServer (D:\Projects\snkrs-play\node_modules\playwright\lib\client\connection.js:69:48)
    at Proxy.<anonymous> (D:\Projects\snkrs-play\node_modules\playwright\lib\client\channelOwner.js:64:61)
    at D:\Projects\snkrs-play\node_modules\playwright\lib\client\browserType.js:64:67
    at BrowserType._wrapApiCall (D:\Projects\snkrs-play\node_modules\playwright\lib\client\channelOwner.js:77:34)
    at BrowserType.launch (D:\Projects\snkrs-play\node_modules\playwright\lib\client\browserType.js:55:21)
    at D:\Projects\snkrs-play\index.js:4:35
    at Object.<anonymous> (D:\Projects\snkrs-play\index.js:7:3)
    at Module._compile (internal/modules/cjs/loader.js:1063:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:12876) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:12876) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

A list of missing libraries was provided. After successful installments, firefox ran fine. I upgraded again to version 1.10 and firefox still works.

https://stackoverflow.com/questions/66984974/firefox-browser-does-not-start-in-playwright

This question is quite close to a "need more focus" question. But let's try to give it some focus:

Does Playwright has access to the cPicker object on the page? Does it has access to the window object?

Yes, you can access both cPicker and the window object inside an evaluate call.

Should I trigger the events from the HTML file itself, and in the callbacks, print in the DOM the result, in some dummy-element, and then infer from that dummy element text that the callbacks fired?

Exactly, or you can assign values to a javascript variable:

const cPicker = new ColorPicker({
  onClickOutside(e){
  },
  onInput(color){
    window['color'] = color;
  },
  onChange(color){
    window['result'] = color;
  }
})

And then

it('Should call all callbacks with correct arguments', async() => {
    await page.goto(`http://localhost:5000/tests/visual/basic.html`, {waitUntil:'load'})

    // Wait until the next frame
    await page.evaluate(() => new Promise(requestAnimationFrame))

    // Act
   
    // Assert
    const result = await page.evaluate(() => window['color']);
    // Check the value
})

https://stackoverflow.com/questions/65477895/jest-playwright-test-callbacks-of-event-based-dom-library

Assuming you are not running test with the --runinband flag, the simple answer is yes but it depends ????

There is a pretty comprehensive GitHub issue jest#6957 that explains certain cases of when tests are run concurrently or in parallel. But it seems to depend on a lot of edge cases where jest tries its best to determine the fastest way to run the tests given the circumstances.

To my knowledge there is no way to force jest to run in parallel.

Aside

Have you considered using playwright instead of puppeteer with jest? Playwright has their own internally built testing library called @playwright/test that is used in place of jest with a similar API. This library allows for explicitly defining test groups in a single file to run in parallel (i.e. test.describe.parallel) or serially (i.e. test.describe.serial). Or even to run all tests in parallel via a config option.

// parallel
test.describe.parallel('group', () => {
  test('runs in parallel 1', async ({ page }) => {});
  test('runs in parallel 2', async ({ page }) => {});
});

// serial
test.describe.serial('group', () => {
  test('runs first', async ({ page }) => {});
  test('runs second', async ({ page }) => {});
});

https://stackoverflow.com/questions/73497773/how-to-run-a-list-of-test-suites-in-a-single-file-concurrently-in-jest

I found the error. It was because of some missing libraries need. I discovered this when I downgraded playwright to version 1.9 and ran the the code then this was the error msg:

(node:12876) UnhandledPromiseRejectionWarning: browserType.launch: Host system is missing dependencies!

Some of the Universal C Runtime files cannot be found on the system. You can fix
that by installing Microsoft Visual C++ Redistributable for Visual Studio from:
https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads

Full list of missing libraries:
    vcruntime140.dll
    msvcp140.dll
Error
    at Object.captureStackTrace (D:\Projects\snkrs-play\node_modules\playwright\lib\utils\stackTrace.js:48:19)
    at Connection.sendMessageToServer (D:\Projects\snkrs-play\node_modules\playwright\lib\client\connection.js:69:48)
    at Proxy.<anonymous> (D:\Projects\snkrs-play\node_modules\playwright\lib\client\channelOwner.js:64:61)
    at D:\Projects\snkrs-play\node_modules\playwright\lib\client\browserType.js:64:67
    at BrowserType._wrapApiCall (D:\Projects\snkrs-play\node_modules\playwright\lib\client\channelOwner.js:77:34)
    at BrowserType.launch (D:\Projects\snkrs-play\node_modules\playwright\lib\client\browserType.js:55:21)
    at D:\Projects\snkrs-play\index.js:4:35
    at Object.<anonymous> (D:\Projects\snkrs-play\index.js:7:3)
    at Module._compile (internal/modules/cjs/loader.js:1063:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:12876) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:12876) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

A list of missing libraries was provided. After successful installments, firefox ran fine. I upgraded again to version 1.10 and firefox still works.

https://stackoverflow.com/questions/66984974/firefox-browser-does-not-start-in-playwright

Blogs

Check out the latest blogs from LambdaTest on this topic:

And the Winner Is: Aggregate Model-based Testing

In my last blog, I investigated both the stateless and the stateful class of model-based testing. Both have some advantages and disadvantages. You can use them for different types of systems, depending on whether a stateful solution is required or a stateless one is enough. However, a better solution is to use an aggregate technique that is appropriate for each system. Currently, the only aggregate solution is action-state testing, introduced in the book Paradigm Shift in Software Testing. This method is implemented in Harmony.

How To Automate Desktops Apps Using WinAppDriver

April 2020 Platform Updates: New Browser, Better Performance & Much Much More!

Howdy testers! If you’re reading this article I suggest you keep a diary & a pen handy because we’ve added numerous exciting features to our cross browser testing cloud and I am about to share them with you right away!

Test Optimization for Continuous Integration

“Test frequently and early.” If you’ve been following my testing agenda, you’re probably sick of hearing me repeat that. However, it is making sense that if your tests detect an issue soon after it occurs, it will be easier to resolve. This is one of the guiding concepts that makes continuous integration such an effective method. I’ve encountered several teams who have a lot of automated tests but don’t use them as part of a continuous integration approach. There are frequently various reasons why the team believes these tests cannot be used with continuous integration. Perhaps the tests take too long to run, or they are not dependable enough to provide correct results on their own, necessitating human interpretation.

Failures may be inevitable, but that doesn’t prevent success

Playwright tutorial

LambdaTest’s Playwright tutorial will give you a broader idea about the Playwright automation framework, its unique features, and use cases with examples to exceed your understanding of Playwright testing. This tutorial will give A to Z guidance, from installing the Playwright framework to some best practices and advanced concepts.

Chapters:

What is Playwright : Playwright is comparatively new but has gained good popularity. Get to know some history of the Playwright with some interesting facts connected with it.
How To Install Playwright : Learn in detail about what basic configuration and dependencies are required for installing Playwright and run a test. Get a step-by-step direction for installing the Playwright automation framework.
Playwright Futuristic Features: Launched in 2020, Playwright gained huge popularity quickly because of some obliging features such as Playwright Test Generator and Inspector, Playwright Reporter, Playwright auto-waiting mechanism and etc. Read up on those features to master Playwright testing.
What is Component Testing: Component testing in Playwright is a unique feature that allows a tester to test a single component of a web application without integrating them with other elements. Learn how to perform Component testing on the Playwright automation framework.
Inputs And Buttons In Playwright: Every website has Input boxes and buttons; learn about testing inputs and buttons with different scenarios and examples.
Functions and Selectors in Playwright: Learn how to launch the Chromium browser with Playwright. Also, gain a better understanding of some important functions like “BrowserContext,” which allows you to run multiple browser sessions, and “newPage” which interacts with a page.
Handling Alerts and Dropdowns in Playwright : Playwright interact with different types of alerts and pop-ups, such as simple, confirmation, and prompt, and different types of dropdowns, such as single selector and multi-selector get your hands-on with handling alerts and dropdown in Playright testing.
Playwright vs Puppeteer: Get to know about the difference between two testing frameworks and how they are different than one another, which browsers they support, and what features they provide.
Run Playwright Tests on LambdaTest: Playwright testing with LambdaTest leverages test performance to the utmost. You can run multiple Playwright tests in Parallel with the LammbdaTest test cloud. Get a step-by-step guide to run your Playwright test on the LambdaTest platform.
Playwright Python Tutorial: Playwright automation framework support all major languages such as Python, JavaScript, TypeScript, .NET and etc. However, there are various advantages to Python end-to-end testing with Playwright because of its versatile utility. Get the hang of Playwright python testing with this chapter.
Playwright End To End Testing Tutorial: Get your hands on with Playwright end-to-end testing and learn to use some exciting features such as TraceViewer, Debugging, Networking, Component testing, Visual testing, and many more.
Playwright Video Tutorial: Watch the video tutorials on Playwright testing from experts and get a consecutive in-depth explanation of Playwright automation testing.