Playwright VS Code extension shows 'no tests have been found' and connect ETIMEDOUT on the IPv6 loopback

TL;DR

The Node-side fix shipped in v24.14.0. Multiple users confirmed that upgrading Node.js to v24.15.0 resolves both the ETIMEDOUT error and the missing tests. If you see this combo of symptoms, upgrade Node to v24.15.0 or later.

When to use

You are seeing this: The extension talks to its language server over the IPv6 loopback, and a Node.js DNS regression broke that path: the c-ares fallback detection did not recognize the loopback address as a loopback DNS server on Windows, so the connection timed out and the... Use this skill when you run into "Playwright VS Code extension shows 'no tests have been found' and connect ETIMEDOUT on the IPv6 loopback".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

Versions mentioned in the source: v24.14.0, v24.15.0. If you are on something much newer or older, the details may have shifted.

Steps

1. The extension talks to its language server over the IPv6 loopback, and a Node.js DNS regression broke that path: the c-ares fallback detection did not recognize the loopback address as a loopback DNS server on Windows, so the connection timed out and the extension reported no tests. The Node-side fix shipped in v24.14.0. Multiple users confirmed that upgrading Node.js to v24.15.0 resolves both the ETIMEDOUT error and the missing tests. If you see this combo of symptoms, upgrade Node to v24.15.0 or later.

Asked in the thread (https://vectle.com/threads/thr_UNKZXuo6i8kRxBfiJJUVrg): The Playwright VS Code extension failed to load tests: the Testing tab showed no tests found, playwright.config.ts showed the error connect ETIMEDOUT on the IPv6 loopback port, and the dev-tools console showed Illegal argument: character must be non-negative. Everything worked from the CLI (npx playwright test ran fine), and the issue reproduced on clean projects. It appeared after a Windows update, on Node 24.13-24.14 with Playwright 1.57-1.58 and extension 1.1.17. The verified answer: The extension talks to its language server over the IPv6 loopback, and a Node.js DNS regression broke that path: the c-ares fallback detection did not recognize the loopback address as a loopback DNS server on Windows, so the connection timed out and the extension reported no tests. The Node-side fix shipped in v24.14.0. Multiple users confirmed that upgrading Node.js to v24.15.0 resolves both the ETIMEDOUT error and the missing tests. If you see this combo of symptoms, upgrade Node to v24.15.0 or later.

Source: https://github.com/microsoft/playwright/issues/40226 Thread: https://vectle.com/threads/thr_UNKZXuo6i8kRxBfiJJUVrg