[Bug]: Chromium returns "en-US@posix" for navigator.language

[Torgen]

Version

1.49.0 and 1.49.1

Steps to reproduce

in node repl:

const { chromium } = require('playwright')
await browser = chromium.launch()
await page = browser.newPage()
await page.evaluate("navigator.language")

Expected behavior

It should return any legal BCP47 language code.

Actual behavior

'en-US@posix'

Additional context

Running on Ubuntu 24.04 on WSL2, but something similarly illegal is getting returned on my github actions runners based on how my tests are failing in Torgen/codex-blackboard#1361 and Torgen/codex-blackboard#1374. Basically it's consistent with https://github.com/Torgen/codex-blackboard/blob/master/client/imports/timestamp.js throwing an error when I try to pass navigator.language to the constructor of Intl.DateTimeFormat at the module top level. I don't expect you to run those, but they're how I noticed there was a problem.

Environment

System:
    OS: Linux 5.4 Ubuntu 24.04 LTS 24.04 LTS (Noble Numbat)
    CPU: (16) x64 Intel(R) Core(TM) i9-9900K CPU @ 3.60GHz
    Memory: 7.06 GB / 7.73 GB
    Container: Yes
  Binaries:
    Node: 18.19.1 - /usr/bin/node
    Yarn: 1.22.22 - /usr/local/bin/yarn
    npm: 9.2.0 - /usr/bin/npm
  IDEs:
    VSCode: 1.95.3 - /mnt/c/Users/Dan/AppData/Local/Programs/Microsoft VS Code/bin/code
  Languages:
    Bash: 5.2.21 - /usr/bin/bash
  npmPackages:
    @playwright/browser-chromium: ^1.49.1 => 1.49.1
    @playwright/browser-firefox: ^1.49.1 => 1.49.1
    playwright: ^1.49.1 => 1.49.1

[pavelfeldman]

adobe/react-spectrum#7457 has a good analysis and links. Sounds like overriding language in the config is the only workaround.

[krassowski]

This has bitten Jupyter ecosystem as well, breaking CI on dozens of repositories. If my understanding is correct, this would be a bug in Chromium and not in playwright, correct?

I see that the Chromium team stumbled upon this in May and committed a workaround for their use case in https://issues.chromium.org/issues/337047877.

[Torgen]

Tried setting LANG=en_US on both my node repl example and on my actual tests and it seemed to be an effective workaround.

[mxschmitt]

I was not able to reproduce on WSL2 with Ubuntu 24.04 on Windows 11. @Torgen what was the original value of echo $LANG? or did env yield something interesting?

[Torgen]

$ echo $LANG
C.UTF-8

[pavelfeldman]

@krassowski

If my understanding is correct, this would be a bug in Chromium and not in playwright, correct?

Yes, and the workaround with setting the LANG env variable above sounds like the easiest fix. It is a little hard to file the issue upstream https://issues.chromium.org/issues?q=status:open without the repro. If you have the repro, could you file it and mention it here? The issue you point to only mentions it briefly, so it was not addressed in full.