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How to use toHaveScreenshot method in Playwright Internal

Best JavaScript code snippet using playwright-internal

Using AI Code Generation

1const { toMatchImageSnapshot } = require('jest-image-snapshot');2expect.extend({ toMatchImageSnapshot });3const { test, expect } = require('@playwright/test');4test('test screenshot', async ({ page }) => {5  const image = await page.screenshot();6  expect(image).toMatchImageSnapshot();7});8const { test, expect } = require('@playwright/test');9test('test screenshot', async ({ page }) => {10  await expect(page).toHaveScreenshot();11});12module.exports = {13  customDiffConfig: { threshold: 0.1 },14};15{16  "scripts": {17  },18  "dependencies": {19  },20  "devDependencies": {21  }22}23  ✓ test screenshot (1096ms)24    expect(received).toMatchImageSnapshot()

Using AI Code Generation

1const { toHaveScreenshot } = require('@playwright/test');2expect.extend({ toHaveScreenshot });3const { toHaveScreenshot } = require('@playwright/test');4expect.extend({ toHaveScreenshot });5test('should take screenshot', async ({ page, toMatchSnapshot }) => {6  const screenshot = await page.screenshot();7  expect(screenshot).toHaveScreenshot('playwright-screenshot.png');8});9The first line of code imports the

Using AI Code Generation

1const { toMatchImageSnapshot } = require('jest-image-snapshot');2expect.extend({ toMatchImageSnapshot });3const { chromium } = require('playwright');4const fs = require('fs');5const path = require('path');6const { promisify } = require('util');7const mkdir = promisify(fs.mkdir);8const writeFile = promisify(fs.writeFile);9(async () => {10  const browser = await chromium.launch({ headless: false });11  const context = await browser.newContext();12  const page = await context.newPage();13  await page.screenshot({ path: 'screenshot.png' });14  const image = fs.readFileSync(path.join(__dirname, 'screenshot.png'));15  expect(image).toMatchImageSnapshot();16  await browser.close();17})();18{19  "scripts": {20  },21  "dependencies": {22  }23}

Using AI Code Generation

1const { test, expect } = require('@playwright/test');2test('my test', async ({ page }) => {3  const image = await page.screenshot();4  expect(image).toHaveScreenshot({ threshold: 0.5 });5});6const { test, expect } = require('@playwright/test');7test('my test', async ({ page }) => {8  const image = await page.screenshot();9  expect(image).toHaveScreenshot({ threshold: 0.5 });10});11import { test, expect } from '@playwright/test';12test('my test', async ({ page }) => {13  const image = await page.screenshot();14  expect(image).toHaveScreenshot({ threshold: 0.5 });15});16import { test, expect } from '@playwright/test';17test('my test', async ({ page }) => {18  const image = await page.screenshot();19  expect(image).toHaveScreenshot({ threshold: 0.5 });20});21import { test, expect } from '@playwright/test';22test('my test', async ({ page }) => {23  const image = await page.screenshot();24  expect(image).toHaveScreenshot({ threshold: 0.5 });25});

Using AI Code Generation

1const { toHaveScreenshot } = require('@playwright/test');2expect.extend({ toHaveScreenshot });3expect(await page.screenshot()).toHaveScreenshot({4});5expect(await page.screenshot()).toHaveScreenshot({6});7expect(await page.screenshot()).toHaveScreenshot({8});9expect(await page.screenshot()).toHaveScreenshot({10});11expect(await page.screenshot()).toHaveScreenshot({12  clip: { x: 0, y: 0, width: 1000, height: 500 }13});14expect(await page.screenshot()).toHaveScreenshot({15  clip: { x: 0, y: 0, width: 1000, height: 500 },16});17expect(await page.screenshot()).toHaveScreenshot({18  clip: { x: 0, y: 0, width: 1000, height: 500 },19});20expect(await page.screenshot()).toHaveScreenshot({

Using AI Code Generation

1import { toHaveScreenshot } from '@playwright/test';2expect.extend({ toHaveScreenshot });3await expect(page).toHaveScreenshot({4});5await expect(page).toHaveScreenshot({6    options: {7    }8});9await expect(page).toHaveScreenshot({10    options: {11    },12    screenshotOptions: {13    }14});15await expect(page).toHaveScreenshot({16    options: {17    },18    screenshotOptions: {19    },20    customScreenshot: async () => {21        const screenshot = await page.screenshot({22        });23        return screenshot;24    }25});26await expect(page).toHaveScreenshot({27    options: {28    },29    screenshotOptions: {30    },31    customScreenshot: async () => {32        const screenshot = await page.screenshot({33        });34        return screenshot;35    },36    customBaseline: async () => {37        const baseline = await fs.readFile('baseline.png');38        return baseline;39    }40});41await expect(page).toHaveScreenshot({42    options: {

StackOverFlow community discussions

Questions

Discussion

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

Running Playwright in Azure Function

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?

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

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

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