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

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

The problem

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 fix

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

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