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Vitest

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Velocity5.0

Blazing-fast unit test framework powered by Vite

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Vitest 5 is in bug-fix mode: the second RC is almost entirely hardening

testingbrowser-moderelease-candidatestabilitytooling
◆Current state
rc.2 carries one feature — a custom title for the GitHub Actions summary — and otherwise fixes the failure modes the RC period surfaced. The browser mode gets most of it: failing instead of hanging when the browser stops responding, exiting cleanly on disconnect during cancellation, and triggering Chromium GC when disk runs low. Snapshot evaluation moved server-side to work under a no-unsafe-eval CSP, and the UI now requires auth for coverage reports and every subtree request.
◆Where it's heading
The v5 line has spent four betas and two candidates reshaping config resolution, projects, mocking defaults, and the benchmark API; this candidate adds nothing to that surface and only stabilizes it. The concentration of browser-mode and pool fixes says that is where the remaining risk sits, and where real-world RC adoption is finding edges.
◆Prediction
On this trajectory the next tag is either a final 5.0.0 or one more candidate, with browser mode the deciding factor rather than any remaining API work.

◆Recent moves

  1. 1d ago

    Vitest 5 rc.2: browser mode stops hanging, snapshots work under strict CSP

    A hardening candidate rather than a feature one. The v5 API surface is settled and the work has moved to browser-mode failure handling, worker exit reporting, and running snapshots under a no-unsafe-eval CSP.

    View source ↗
  2. 7d ago

    Vitest 5 RC: nested projects, shared Vite server, unawaited assertions fail

    The first candidate, which brought nested projects, a shared Vite server, and unawaited assertions becoming failures — the last cut that changed the v5 surface.

    View source ↗
  3. 25d ago

    Vitest 5 beta.7: config resolution split out, pluggable benchmark providers

    Beta 7 split config resolution into its own step and made benchmark providers pluggable, part of the structural work v5 is built on.

    View source ↗
  4. 1mo ago

    Vitest 5 beta.6: mocks clear by default, webdriverio removed, vi.when() added

    Beta 6 flipped mocks to clear by default, dropped webdriverio, and added vi.when() — one of the breaking-default cuts of this cycle.

    View source ↗
  5. 2mo ago

    Vitest 5 beta.5: no ancestor config lookup, @vitest/runner inlined

    Beta 5 removed ancestor config lookup and inlined @vitest/runner, continuing the config and packaging cleanup.

    View source ↗
  6. 2mo ago

    Vitest 5 beta.4: benchmark API rewritten, strict hoisting and locators

    Beta 4 rewrote the benchmark API and tightened hoisting and locators, opening the run of breaking changes v5 is built around.

    View source ↗