Impact Score: 5/10
Vitest v4.1.9 — Release Notes & Engineering Impact
Source available — automated, not human-reviewed
Component: vitest · Channel: stable. Automated analysis, not a compatibility certification. How this works.
Analysis updated: 2026-11-01.
⚡ Executive Summary (TL;DR)
Vitest v4.1.9. Source highlight: Fix `importOriginal` with optimizer and query import [backport to v4] - by **Hiroshi Ogawa**, **David Harris**, **Codex**and **Vladimir** in https://github.com/vitest-dev/vitest/issues/10546 <samp>(a5180)</samp>
Who Does This Impact? (Role-Based Analysis)
💻 Software Engineers & Devs
Check the source notes against the package and APIs you use before upgrading.
📊 Product & Engineering Leads
Use the documented changes to assess relevance to your product; release frequency alone is not a quality measure.
⚙️ DevOps & Security
Verify the target version, runtime requirements and rollback procedure in the official documentation.
🔧 Bug Fixes & Patches (5)
- Fix `importOriginal` with optimizer and query import [backport to v4] - by **Hiroshi Ogawa**, **David Harris**, **Codex**and **Vladimir** in https://github.com/vitest-dev/vitest/issues/10546 <samp>(a5180)</samp>
- Wait for orchestrator readiness before resolving browser sessions [backport to v4] - by **Vladimir** and **Séamus O'Connor** in https://github.com/vitest-dev/vitest/issues/10555 <samp>(7fb29)</samp>
- Wait for iframe tester readiness before preparing [backport to v4] - by **Vladimir** and **Séamus O'Connor** in https://github.com/vitest-dev/vitest/issues/10497 and https://github.com/vitest-dev/vitest/issues/10556 <samp>(fbc62)</samp>
- Hoist vi.mock() for vite-plus/test imports [backport to v4] - by **Hiroshi Ogawa**, **LongYinan**, **Claude Opus 4.8** and **Vladimir** in https://github.com/vitest-dev/vitest/issues/10548 <samp>(2c955)</samp>
- Prevent test run hang on worker crash [backport to v4] - by **Ari Perkkiö** and **Jattioui Ismail** in https://github.com/vitest-dev/vitest/issues/10543 and https://github.com/vitest-dev/vitest/issues/10564 <samp>(934b0)</samp>
📄 View Raw Release Notes (Original Developer Log)
### 🐞 Bug Fixes
- Fix `importOriginal` with optimizer and query import [backport to v4] - by **Hiroshi Ogawa**, **David Harris**, **Codex**and **Vladimir** in https://github.com/vitest-dev/vitest/issues/10546 [<samp>(a5180)</samp>](https://github.com/vitest-dev/vitest/commit/a5180190c)
- **browser**:
- Wait for orchestrator readiness before resolving browser sessions [backport to v4] - by **Vladimir** and **Séamus O'Connor** in https://github.com/vitest-dev/vitest/issues/10555 [<samp>(7fb29)</samp>](https://github.com/vitest-dev/vitest/commit/7fb29651a)
- Wait for iframe tester readiness before preparing [backport to v4] - by **Vladimir** and **Séamus O'Connor** in https://github.com/vitest-dev/vitest/issues/10497 and https://github.com/vitest-dev/vitest/issues/10556 [<samp>(fbc62)</samp>](https://github.com/vitest-dev/vitest/commit/fbc626c40)
- **mocker**:
- Hoist vi.mock() for vite-plus/test imports [backport to v4] - by **Hiroshi Ogawa**, **LongYinan**, **Claude Opus 4.8** and **Vladimir** in https://github.com/vitest-dev/vitest/issues/10548 [<samp>(2c955)</samp>](https://github.com/vitest-dev/vitest/commit/2c9559c02)
- **pool**:
- Prevent test run hang on worker crash [backport to v4] - by **Ari Perkkiö** and **Jattioui Ismail** in https://github.com/vitest-dev/vitest/issues/10543 and https://github.com/vitest-dev/vitest/issues/10564 [<samp>(934b0)</samp>](https://github.com/vitest-dev/vitest/commit/934b0f587)
##### [View changes on GitHub](https://github.com/vitest-dev/vitest/compare/v4.1.8...v4.1.9)