migrating-to-vitest-4

Migrate Vitest 2.x/3.x to 4.x by updating config keys like maxWorkers, include, and projects; replacing workspace with projects; updating server.deps; and adjusting pool and coverage settings. Follow step-by-step before/after examples for each change, then run your full test suite to verify.

Vitest 4.x updates pool options for test execution and browser provider imports. Browser mode now requires new provider import paths. Review the migration table for specific pool type changes and update your browser configuration to use the new import structure.

Yes, test files may require updates to align with Vitest 4.x architecture changes, particularly imports and browser provider references. The migration guidance covers concrete before/after file examples and per-project adjustment workflows.

Browser provider dependencies and their imports change in Vitest 4.x. Install updated provider packages and adjust your imports to match the new structure. The migration covers dependency version updates and new import paths for each provider.

Replace workspace with projects in your Vitest 4.x config and restructure project definitions accordingly. The migration provides direct before/after configuration examples showing how to map workspace entries to the new projects array format.

Vitest 4.x updates the server namespace, including server.deps configuration keys. Review the migration table for all server-related key changes and update your vite.config or vitest.config accordingly.