[Bug] Browser mode: Cannot convert a Symbol value to a string in console.error

[Suto-Michimasa]

Describe the bug

In vitest 4.0.16 browser mode (@vitest/browser + Playwright runner), when console.error is called with an object containing Symbol properties, the baseFormat function in @vitest/utils throws a TypeError.

This commonly occurs with RTK Query error objects, which contain Symbol keys like Symbol() as internal markers. For example:

// RTK Query error object structure (simplified)
{
  status: "FETCH_ERROR",
  error: "...",
  [Symbol()]: "internal marker"  // This causes the crash
}

This is a regression from 4.0.15.

Reproduction

https://github.com/Suto-Michimasa/vitest-symbol-repro

Steps to reproduce

git clone https://github.com/Suto-Michimasa/vitest-symbol-repro
cd vitest-symbol-repro
pnpm install
pnpm test:browser

Stack trace

TypeError: Cannot convert a Symbol value to a string
    at baseFormat (@vitest/utils@4.0.16/dist/display.js:700:15)
    at browserFormat (@vitest/utils@4.0.16/dist/display.js:711:9)
    at processLog (__vitest_browser__/tester.js:1202:10)
    at console.error (__vitest_browser__/tester.js:1198:23)

Regression confirmation

Downgrading to 4.0.15 resolves the issue:

pnpm up vitest@4.0.15 @vitest/browser@4.0.15 @vitest/browser-playwright@4.0.15
pnpm test:browser  # passes

Expected behavior

• Symbol properties should be safely handled during console output formatting (ignored or converted via String(symbol))
• Tests should pass without TypeError

Actual behavior

• Tests fail with TypeError: Cannot convert a Symbol value to a string
• The browser runner crashes when formatting objects with Symbol keys

System Info

- vitest: 4.0.16
- @vitest/browser: 4.0.16
- @vitest/browser-playwright: 4.0.16
- playwright: 1.57.0
- Browser: Chromium (via Playwright)
- Node.js: 20+
- OS: macOS

Used Package Manager

pnpm

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