Some error messages are duplicated in UI

[hi-ogawa]

Describe the bug

For example, updating expect.element assertion to fail in examples/lit

  it('should show name props', async () => {
    await expect.element(page.getByRole('heading'), { timeout: 2000 }).toHaveTextContent('foo')
  })

then running UI, the terminal errors are not duplicated:

$ pnpm -C examples/lit test --browser.headless --browser.traceView --ui 

> @vitest/example-lit@ test /home/hiroshi/code/others/vitest-wt2/examples/lit
> vitest --browser.headless --browser.traceView --ui


 DEV  v5.0.0-beta.1 /home/hiroshi/code/others/vitest-wt2/examples/lit
      UI started at http://localhost:51204/__vitest__/

stderr | unknown test
Lit is in dev mode. Not recommended for production! See https://lit.dev/msg/dev-mode for more information.
 ❯  chromium  test/basic.test.ts (2 tests | 1 failed) 2220ms
   ❯ Button with increment (2)
     ✓ should increment the count on each click 104ms
     × should show name props 2115ms

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ Failed Tests 1 ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯

 FAIL   chromium  test/basic.test.ts > Button with increment > should show name props
Error: expect(element).toHaveTextContent()

Expected element to have text content:
  foo
Received:
  Hello, World!

Failure screenshot:
  - test/__screenshots__/basic.test.ts/Button-with-increment-should-show-name-props-1.png

 ❯ test/basic.test.ts:27:71
     25|   it('should show name props', async () => {
     26|     // await expect.element(page.getByRole('heading')).toHaveTextContent('World')
     27|     await expect.element(page.getByRole('heading'), { timeout: 2000 }).toHaveTextConten…
       |                                                                       ^
     28|   })
     29|

Caused by: Error: Matcher did not succeed in time.
 ❯ test/basic.test.ts:27:4

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[1/1]⎯


 Test Files  1 failed (1)
      Tests  1 failed | 1 passed (2)
   Start at  11:24:51
   Duration  3.05s (transform 0ms, setup 0ms, import 16ms, tests 2.22s, environment 0ms)

 FAIL  Tests failed. Watching for file changes...
       press h to show help, press q to quit

But, UI shows Error: expect(element).toHaveTextContent() twice as below:

Reproduction

See above

System Info

$ pnpm dlx envinfo --system --npmPackages '{vitest*,@vitest/*,vite,@vitejs/*,playwright,webdriverio}' --binaries --browsers
Packages: +1
+
Progress: resolved 1, reused 1, downloaded 0, added 1, done

  System:
    OS: Linux 7.0 Arch Linux
    CPU: (16) x64 12th Gen Intel(R) Core(TM) i7-12650H
    Memory: 15.18 GB / 31.05 GB
    Container: Yes
    Shell: 5.3.9 - /usr/bin/bash
  Binaries:
    Node: 24.15.0 - /home/hiroshi/.vite-plus/js_runtime/node/24.15.0/bin/node
    npm: 11.12.1 - /home/hiroshi/.vite-plus/js_runtime/node/24.15.0/bin/npm
    pnpm: 10.31.0 - /home/hiroshi/.vite-plus/bin/pnpm
    bun: 1.3.9 - /home/hiroshi/.bun/bin/bun
    Deno: 2.6.6 - /home/hiroshi/.local/bin/deno
  Browsers:
    Firefox: 150.0.1
    Firefox Developer Edition: 150.0.1
  npmPackages:
    @vitest/browser: workspace:* => 5.0.0-beta.1 
    @vitest/coverage-istanbul: workspace:* => 5.0.0-beta.1 
    @vitest/coverage-v8: workspace:* => 5.0.0-beta.1 
    @vitest/ui: workspace:* => 5.0.0-beta.1 
    vite: 7.1.5 => 7.1.5 
    vitest: workspace:* => 5.0.0-beta.1

Used Package Manager

pnpm

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[hi-ogawa]

It looks like UI glitches with colored error message. Here is a minimal repro https://stackblitz.com/edit/vitest-dev-vitest-dupmnhxo?file=repro.test.ts

import { test } from 'vitest';

test('repro duplicate ANSI error heading in UI', () => {
  const red = '\x1B[31m';
  const reset = '\x1B[0m';
  const message = `${red}yay${reset}`;
  const error = new Error(message);
  throw error;
});