Upgrade to Vitest v4

[AlexanderKaran]

🎯 Changes

Upgrade TanStack Query to use Vitest 4. Most changes were around mocks, testing functions being used and some config tweaks.

A few gotchas I am unsure about:

• Had to pin Vite version in overrides
• Vitest 4 has some changes under the hood that causes a few tests to fail in react-query not 100% sure about the solution

Please let me know if I have messed with things that should not be touched.

✅ Checklist

• [ X] I have followed the steps in the Contributing guide.
• [ X] I have tested this code locally with pnpm run test:pr.

🚀 Release Impact

• This change affects published code, and I have generated a changeset.
• [ X] This change is docs/CI/dev-only (no release).

Summary by CodeRabbit

• Chores
  • Updated Vite from ^6.3.6 to ^6.4.1 across all example projects and integrations
  • Updated root dependencies: @tanstack/config, @types/node, vitest, and related testing tools
  • Enhanced TypeScript configuration for Next.js examples with improved route type support
  • Improved test infrastructure with better mock handling and type annotations

[changeset-bot]

⚠️ No Changeset found

Latest commit: aeefc4c

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

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[coderabbitai]

Walkthrough

Large monorepo dependency and test infrastructure update. Vite bumped from ^6.3.6 to ^6.4.1 across ~40 example and integration package files. Root package.json updated with @tanstack/config, @types/node, @vitest/*, and vitest bumps. Next.js type references added to multiple next-env.d.ts files. Test mocks refactored for type safety; test setup standardized with clearAllMocks and improved spy patterns.

Changes

Cohort / File(s)	Change Summary
Vite devDependency bumps in React examples examples/react/algolia/package.json, examples/react/basic-graphql-request/package.json, examples/react/basic/package.json, examples/react/chat/package.json, examples/react/default-query-function/package.json, examples/react/devtools-panel/package.json, examples/react/eslint-legacy/package.json, examples/react/offline/package.json, examples/react/playground/package.json, examples/react/react-router/package.json, examples/react/rick-morty/package.json, examples/react/shadow-dom/package.json, examples/react/simple/package.json, examples/react/star-wars/package.json, examples/react/suspense/package.json	Updated vite from ^6.3.6 to ^6.4.1 in devDependencies
Vite devDependency bumps in Solid examples examples/solid/basic-graphql-request/package.json, examples/solid/basic/package.json, examples/solid/default-query-function/package.json, examples/solid/simple/package.json	Updated vite from ^6.3.6 to ^6.4.1 in devDependencies
Vite devDependency bumps in Svelte examples examples/svelte/auto-refetching/package.json, examples/svelte/basic/package.json, examples/svelte/load-more-infinite-scroll/package.json, examples/svelte/optimistic-updates/package.json, examples/svelte/playground/package.json, examples/svelte/simple/package.json, examples/svelte/ssr/package.json, examples/svelte/star-wars/package.json	Updated vite from ^6.3.6 to ^6.4.1 in devDependencies
Vite devDependency bumps in Vue examples examples/vue/basic/package.json, examples/vue/dependent-queries/package.json, examples/vue/persister/package.json, examples/vue/simple/package.json	Updated vite from ^6.3.6 to ^6.4.1 in devDependencies
Vite devDependency bumps in integrations integrations/react-vite/package.json, integrations/solid-vite/package.json, integrations/svelte-vite/package.json, integrations/vue-vite/package.json	Updated vite from ^6.3.6 to ^6.4.1 in devDependencies
Next.js route type references examples/react/auto-refetching/next-env.d.ts, examples/react/infinite-query-with-max-pages/next-env.d.ts, examples/react/load-more-infinite-scroll/next-env.d.ts, examples/react/nextjs-suspense-streaming/next-env.d.ts, examples/react/nextjs/next-env.d.ts, examples/react/optimistic-updates-cache/next-env.d.ts, examples/react/optimistic-updates-ui/next-env.d.ts, examples/react/pagination/next-env.d.ts, examples/react/prefetching/next-env.d.ts	Added triple-slash reference directive to ./.next/types/routes.d.ts for Next.js route type resolution
Root dependency updates package.json	Bumped @tanstack/config (^0.20.2 → ^0.22.0), @types/node (^22.15.3 → ^24.10.0), @vitest/coverage-istanbul (3.2.4 → 4.0.6), @vitest/eslint-plugin (^1.1.36 → ^1.4.0), vite (^6.3.6 → ^6.4.1), vitest (3.2.4 → 4.0.8); updated pnpm overrides with vite and @types/node constraints
Vue query mock type refactoring packages/vue-query/src/__mocks__/useBaseQuery.ts, packages/vue-query/src/__mocks__/useQueryClient.ts	Removed explicit Mock<> type annotations; replaced vi.importActual typing approach with typed module alias; removed unrefQueryArgs export
Vue query test infrastructure updates packages/vue-query/src/__tests__/queryClient.test.ts, packages/vue-query/src/__tests__/useQueries.test.ts, packages/vue-query/src/__tests__/useQueryClient.test.ts	Added dynamic prototype spying on QueryClient; switched to vi.clearAllMocks() instead of restoreAllMocks(); broadened expect assertions with objectContaining; refactored vue-demi mocks with namespace import
Angular query test mock setup packages/angular-query-experimental/src/__tests__/inject-devtools-panel.test.ts, packages/angular-query-experimental/src/__tests__/with-devtools.test.ts	Extracted inline mock factories into named helper functions; added vi.clearAllMocks() in beforeEach; added vi.dynamicImportSettled() awaits in test flows
Solid query mock implementation packages/solid-query/src/__tests__/useQueries.test.tsx	Refactored QueriesObserver spy to accept (client, queries) parameters instead of single function argument
React query test updates packages/react-query/src/__tests__/usePrefetchInfiniteQuery.test.tsx, packages/react-query/src/__tests__/useQuery.promise.test.tsx	Added Fallback.mockClear() in afterEach; increased test timeout; expanded fake timer tracking; rewrote cancellation flow assertions with waitFor
Test type annotation updates packages/query-core/src/__tests__/timeoutManager.test.tsx, packages/query-persist-client-core/src/__tests__/createPersister.test.ts	Updated consoleErrorSpy type to MockInstance; replaced toHaveBeenCalledOnce() with toHaveBeenCalledExactlyOnceWith()
Vite config updates packages/query-codemods/vite.config.ts, packages/solid-query-devtools/vite.config.ts	Expanded coverage include pattern from src/\\ to src/\\.{js,ts,cjs,mjs,jsx,tsx}; changed defineConfig import from vite to vitest/config
Vue query devtools dependencies packages/vue-query-devtools/package.json	Updated vite from ^6.3.6 to ^6.4.1 in devDependencies
React query testing dependencies packages/react-query/package.json	Bumped @testing-library/react-render-stream from ^2.0.0 to ^2.0.2

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~15 minutes

• Vite and dependency bumps (~30+ homogeneous package.json updates) are routine and carry minimal risk
• Next.js type reference additions are straightforward and non-breaking
• Mock type annotation cleanup in vue-query is a safe simplification that maintains functionality
• Test infrastructure changes (clearAllMocks vs. restoreAllMocks, mock helper extraction) are intentional patterns and low-risk

Areas requiring extra attention:

• packages/vue-query/src/__tests__/queryClient.test.ts — dynamic prototype spying on QueryClient and broadened assertions with expect.objectContaining warrant validation that expectations remain sound
• packages/react-query/src/__tests__/useQuery.promise.test.tsx — cancellation flow rewrite with waitFor and timer expansion should be verified against intended behavior
• packages/angular-query-experimental/src/__tests__/with-devtools.test.ts — added vi.dynamicImportSettled() awaits across multiple tests; confirm async import handling is necessary and complete

Possibly related PRs

• ci: update workspace config #9671 — Overlapping Vite devDependency bumps across example package.json files
• chore(deps): update dependency vite to ^4.5.14 [security] #9636 — Related Vite version constraint updates in package.json files
• chore(deps): update all non-major dependencies #9712 — Mass dependency bump churn affecting examples and integrations

Suggested labels

dependencies, package: react-query, package: solid-query-devtools, package: vue-query, package: query-core, test-infrastructure

Suggested reviewers

• TkDodo
• ArturKustyaev

Poem

🐰 A rabbit hops through package trees,
Vite bumps dance upon the breeze,
Mock types cleaned, tests aligned,
Dependencies refined.
Routes typed, timers await—
All updates, truly great! 🥕

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'Upgrade to Vitest v4' clearly and concisely summarizes the main change: upgrading the testing framework from Vitest v3 to v4, which aligns with the primary objective evident in the changeset.
Description check	✅ Passed	The PR description follows the required template with all sections completed: Changes, Checklist, and Release Impact are present and properly filled out.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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