Incompatible with Vitest 3

[benmccann]

Describe the bug

Vitest seems to be using a frozen data structure for resolve conditions

Reproduction URL

sveltejs/kit#13324

Reproduction

I noticed this in the renovate PR to SvelteKit for upgrading to Vitest 3

Logs

prerendering-test-basics@0.0.2-next.0 : test packages/kit/test/prerendering/basics
  
  > prerendering-test-basics@0.0.2-next.0 test /home/runner/work/kit/kit/packages/kit/test/prerendering/basics
  > vitest run
  
  Warning: G] Cannot find base config file "./.svelte-kit/tsconfig.json" [tsconfig.json]
  
      tsconfig.json:7:12:
        7 │   "extends": "./.svelte-kit/tsconfig.json"
          ╵              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  
  
  ⎯⎯⎯⎯⎯⎯⎯ Startup Error ⎯⎯⎯⎯⎯⎯⎯⎯
  TypeError: Cannot add property 3, object is not extensible
      at Array.push (<anonymous>)
      at configEnvironment (file:///home/runner/work/kit/kit/node_modules/.pnpm/@sveltejs+vite-plugin-svelte@5.0.1_svelte@5.2.9_vite@6.0.1_@types+node@18.19.50_lightningcss@1.24.1_/node_modules/@sveltejs/vite-plugin-svelte/src/index.js:76:31)
      at runConfigEnvironmentHook (file:///home/runner/work/kit/kit/node_modules/.pnpm/vite@6.0.1_@types+node@18.19.50_lightningcss@1.24.1/node_modules/vite/dist/node/chunks/dep-BcnkIxro.js:53615:27)
      at resolveConfig (file:///home/runner/work/kit/kit/node_modules/.pnpm/vite@6.0.1_@types+node@18.19.50_lightningcss@1.24.1/node_modules/vite/dist/node/chunks/dep-BcnkIxro.js:53048:9)
      at async _createServer (file:///home/runner/work/kit/kit/node_modules/.pnpm/vite@6.0.1_@types+node@18.19.50_lightningcss@1.24.1/node_modules/vite/dist/node/chunks/dep-BcnkIxro.js:43320:18)
      at async createViteServer (file:///home/runner/work/kit/kit/node_modules/.pnpm/vitest@3.0.0_@types+node@18.19.50_lightningcss@1.24.1/node_modules/vitest/dist/chunks/cli-api.CmJw5Cd_.js:9963:18)
      at async createVitest (file:///home/runner/work/kit/kit/node_modules/.pnpm/vitest@3.0.0_@types+node@18.19.50_lightningcss@1.24.1/node_modules/vitest/dist/chunks/cli-api.CmJw5Cd_.js:13145:18)
      at async prepareVitest (file:///home/runner/work/kit/kit/node_modules/.pnpm/vitest@3.0.0_@types+node@18.19.50_lightningcss@1.24.1/node_modules/vitest/dist/chunks/cli-api.CmJw5Cd_.js:13564:15)
      at async startVitest (file:///home/runner/work/kit/kit/node_modules/.pnpm/vitest@3.0.0_@types+node@18.19.50_lightningcss@1.24.1/node_modules/vitest/dist/chunks/cli-api.CmJw5Cd_.js:13495:15)
      at async start (file:///home/runner/work/kit/kit/node_modules/.pnpm/vitest@3.0.0_@types+node@18.19.50_lightningcss@1.24.1/node_modules/vitest/dist/chunks/cac.DZC9WjGM.js:1571:17)

System Info

vitest 3

[dominikg]

cc @sheremet-va

[dominikg]

repro https://github.com/dominikg/vitest-example-svelte5/tree/chore/updates

[dominikg]

fixed in vitest@3.0.1