[Regression]: Intl.DateTimeFormat().resolvedOptions().locale doesn't work as expected on latest playwright browsers

[vishalshrm539]

Last Good Version

NA

First Bad Version

latest

Basically with any @Playwright/test version, with the latest browsers(installed using npx playwright install)

Steps to reproduce

1. Install the latest playwright browsers using: npx playwright install
2. Execute Intl.DateTimeFormat().resolvedOptions().locale on the console, it doesn't work as expected.

Expected behavior

Execute Intl.DateTimeFormat().resolvedOptions().locale on the console, it doesn't work as expected. It should return 'en-GB' for me but returns 'en-US' rather. This used to work fine with the older browsers.

Actual behavior

Intl.DateTimeFormat().resolvedOptions().locale should return 'en-GB' which is what my Chrome browser returns.

Additional context

No response

Environment

OS: MAC

[yury-s]

Please follow our bug template and share a reproducible example which we could run locally. I was not able to reproduce the issue with the following test:

import { expect, test } from '@playwright/test';

test.use({ locale: 'en-GB' });

test('locale', async ({ page }) => {
  expect(await page.evaluate(() => Intl.DateTimeFormat().resolvedOptions().locale)).toBe('en-GB');
});

[yury-s]

Closing per the response above, feel free to open a new issue if it doesn't work.

[vishalshrm539]

@yury-s My concern was if I run a playwright test in Chromium browser then the Intl.DateTimeFormat().resolvedOptions().locale API doesn't return en-GB(but return en-US rather) which is what I expect as my Chrome browser returns that(i.e. en-GB).

I don't want to set the locale using test.use({ locale: 'en-GB' });.

In other words, why the Intl.DateTimeFormat().resolvedOptions().locale behaves differently in the Playwright Chromium browser and the Chrome in my machine. Shouldn't the two behave the same?