⚠️ Breaking Change
Impact Score: 7/10
Vitest v0.27.0 — 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.
Breaking-change evidence from the source
🚨 Breaking Changes - Deprecate "error" on result, store errors in "errors" - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/2586 [<samp>(e641a)</samp>](https://github.com/vitest-dev/vitest/commit/e641a110)
⚡ Executive Summary (TL;DR)
Vitest v0.27.0. Source highlight: 🚨 Breaking Changes
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.
⚠️ Breaking Changes & Deprecations (1)
- 🚨 Breaking Changes - Deprecate "error" on result, store errors in "errors" - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/2586 [<samp>(e641a)</samp>](https://github.com/vitest-dev/vitest/commit/e641a110)
✨ New Features & Capabilities (1)
- **coverage**: report only changed files when using istanbul coverage with watch mode - by @g4rry420 in https://github.com/vitest-dev/vitest/issues/2385 <samp>(bf872)</samp>
⚡ Performance & Enhancements (1)
- Improve vi.mock performance - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/2594 <samp>(09d19)</samp>
🔧 Bug Fixes & Patches (6)
- Return mock path only when mocked - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/2619 <samp>(f8ac2)</samp>
- Allow mocking CJS module with interoped default - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/2598 <samp>(6b3e3)</samp>
- Avoid random ENOTEMPTY errors - by @AriPerkkio in https://github.com/vitest-dev/vitest/issues/2620 <samp>(59766)</samp>
- Always inline assets and modules with special Vite queries - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/2617 <samp>(fed1c)</samp>
- Allow overrides reporter via cli option - by @mysteryven and @sheremet-va in https://github.com/vitest-dev/vitest/issues/2573 <samp>(894f1)</samp>
- Flaky c8 coverage caused by parallel sourcemap constructing - by @AriPerkkio and @sheremet-va in https://github.com/vitest-dev/vitest/issues/2591 <samp>(9a29f)</samp>
📄 View Raw Release Notes (Original Developer Log)
### 🚨 Breaking Changes
- Deprecate "error" on result, store errors in "errors" - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/2586 [<samp>(e641a)</samp>](https://github.com/vitest-dev/vitest/commit/e641a110)
- Split vitest into separate packages, but still bundle them for the time being - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/2575 [<samp>(c8e6f)</samp>](https://github.com/vitest-dev/vitest/commit/c8e6fb69)
### 🚀 Features
- **coverage**: report only changed files when using istanbul coverage with watch mode - by @g4rry420 in https://github.com/vitest-dev/vitest/issues/2385 [<samp>(bf872)</samp>](https://github.com/vitest-dev/vitest/commit/bf87282c)
### 🐞 Bug Fixes
- Return mock path only when mocked - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/2619 [<samp>(f8ac2)</samp>](https://github.com/vitest-dev/vitest/commit/f8ac2094)
- Allow mocking CJS module with interoped default - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/2598 [<samp>(6b3e3)</samp>](https://github.com/vitest-dev/vitest/commit/6b3e36d4)
- Avoid random ENOTEMPTY errors - by @AriPerkkio in https://github.com/vitest-dev/vitest/issues/2620 [<samp>(59766)</samp>](https://github.com/vitest-dev/vitest/commit/59766fa4)
- Always inline assets and modules with special Vite queries - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/2617 [<samp>(fed1c)</samp>](https://github.com/vitest-dev/vitest/commit/fed1cd60)
- **cli**:
- Allow overrides reporter via cli option - by @mysteryven and @sheremet-va in https://github.com/vitest-dev/vitest/issues/2573 [<samp>(894f1)</samp>](https://github.com/vitest-dev/vitest/commit/894f155a)
- **coverage**:
- Flaky c8 coverage caused by parallel sourcemap constructing - by @AriPerkkio and @sheremet-va in https://github.com/vitest-dev/vitest/issues/2591 [<samp>(9a29f)</samp>](https://github.com/vitest-dev/vitest/commit/9a29f984)
- Validate extension, when reporting c8 coverage - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/2626 [<samp>(74463)</samp>](https://github.com/vitest-dev/vitest/commit/7446370c)
### 🏎 Performance
- Improve vi.mock performance - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/2594 [<samp>(09d19)</samp>](https://github.com/vitest-dev/vitest/commit/09d19892)
##### [View changes on GitHub](https://github.com/vitest-dev/vitest/compare/v0.26.3...v0.27.0)