@vitest_dev

Testing framework powered by @vite_js ⚡️, brought to you by @voidzerodev | Bluesky: https://xitter.cf/t.co/vS4yqK4RGr 🦋

 Bluesky
vitest.dev
Joined December 2021
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Vitest 4 is out! - Browser Mode is Stable - Visual Regression Testing - Improved Debugging - Pool Stabilization - New APIs - Bug Fixes Stay updated with our blog post: vitest.dev/blog/vitest-4

Announcing Vitest 4.0

Vitest 4.0 Release Announcement

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Are you in Amsterdam (or NL) this Thursday? Then you should join our @vitest_dev x npmx meetup! guild.host/events/vitest-x-n… See y’all there! 👀

vitest x npmx | Guild

Sep 24th 6:00PM: Join us in Amsterdam for a joint event with the Vitest and npmx communities! A huge thank you to Biscuit for hosting us Schedule:

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🚀 @vitest_dev 5.0.1 is out with more than 18 fixes Among them: `define` values are no longer double-quoted in browser mode! It also includes a focused Trace View layout which is used by the Vitest VS Code extension. Time to update 👀 github.com/vitest-dev/vitest…

Release v5.0.1 · vitest-dev/vitest

   🚀 Features ui: Move trace attempts selector to viewer header  -  by @hi-ogawa, Hiroshi Ogawa and Codex in #11189 (5dc4b) Add focused trace view layout mode  -  by @hi-ogawa, Hiroshi Ogawa, Ope...

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Vitest retweeted
VoidZero
@voidzerodevJun 4
VoidZero is joining Cloudflare. Our mission stays the same: to make JavaScript developers more productive than ever before. Vite, Vitest, Rolldown, Oxc, and Vite+ remain MIT-licensed. Evan and the VoidZero team will continue leading them. Cloudflare shares our commitment to open source. Together, we can keep investing in the tooling developers rely on every day, while bringing the Vite ecosystem and Cloudflare’s platform even closer together.
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We've published a Browser Mode security advisory. CDP-capable providers like Playwright Chromium with the browser API exposed to the network allowed attackers to run code on the host. Update vitest/browser to 5.0.0-beta.4, 4.1.8, or 3.2.6. Vite+ users: Upgrade to 0.1.24
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github.com/vitest-dev/vitest…

Exposed Browser Mode API Can Proxy CDP and Overwrite Config Files, Leading to RCE

## Summary Vitest Browser Mode exposes a `cdp()` API that forwards raw Chrome DevTools Protocol (CDP) methods over the Vitest browser WebSocket RPC. CDP is not gated by `browser.api.allowWrite`,...

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We’re launching early access for Vitest visual testing with Chromatic! ⚡️ Built with @vitest_dev core maintainer Ari Perkkio, Chromatic adds visual testing to the browser tests you already write. 🧵 (1/4)
vitest-chromatic-integration-early-access-program

ALT vitest-chromatic-integration-early-access-program

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🚨 We are publishing Vitest 4.1.6 and Vitest 5.0.0-beta.3 to resolve recent vulnerabilities: - `--api` and `--ui` exposed arbitrary files to the network - `--api` allowed arbitrary execution - `?otelCarrier` XSS More information on our GitHub security page
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github.com/vitest-dev/vitest…

GitHub

GitHub is where people build software. More than 225 million people use GitHub to discover, fork, and contribute to over 800 million projects.

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Vitest 4.1 is out! 🚀 ✅ Vite 8 support from day 1 🏷️ Test tags to organize, filter & apply shared options 🪝 New hooks for easier tracing, transactions and AsyncLocalStorage 🔍 Async leak detection 🤖 Agent reporter to reduce token usage And much more!
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Read our announcement post for all the details vitest.dev/blog/vitest-4-1.h…

Announcing Vitest 4.1

Vitest 4.1 Release Announcement

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Boris Cherny
@bchernyFeb 28
In the next version of Claude Code.. We're introducing two new Skills: /simplify and /batch. I have been using both daily, and am excited to share them with everyone. Combined, these kills automate much of the work it used to take to (1) shepherd a pull request to production and (2) perform straightforward, parallelizable code migrations.
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Flaky tests and memory leaks are the worst. @vitest_dev now has a --detect-async-leaks flag that catches uncleared intervals, lingering servers, and other async operations leaking across your tests. ⚠️ Don't run it on every run though. Use it to audit your test suite, then clean things up. Available in the latest 4.1 beta. Big shout out to Ari from the Vitest team for landing this PR! 🔥
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Tests. Vitest's browser mode is stable since Vitest 4.0. Now you can be sure that your tests pass in an *actual* browser environment. vitest.dev/guide/browser/
"Expanding brain meme with 5 stages. Stage 1 (small brain): 'No tests'. Stage 2: 'Testing components by mocking document and window'. Stage 3: 'Testing with jsdom as fake DOM'. Stage 4: 'Testing with happy-dom because jsdom is too slow'. Stage 5 (galaxy brain): 'Testing in an ACTUAL browser with Vitest Browser Mode' with Vitest logo."

ALT "Expanding brain meme with 5 stages. Stage 1 (small brain): 'No tests'. Stage 2: 'Testing components by mocking document and window'. Stage 3: 'Testing with jsdom as fake DOM'. Stage 4: 'Testing with happy-dom because jsdom is too slow'. Stage 5 (galaxy brain): 'Testing in an ACTUAL browser with Vitest Browser Mode' with Vitest logo."

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VoidZero
@voidzerodevFeb 5
✨ What's New in ViteLand: January 2026 Recap ◆ Unified redesign across all VoidZero sites ◆ @vite_js crossed 3 billion npm downloads ◆ @rolldown_rs reached RC status ◆ Lazy Barrel Optimization landed in Rolldown ◆ Oxfmt hit 100% Prettier conformance ◆ Oxlint gets a dynamic .ts config ◆ ...and much more 👀 Full recap below!
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The first beta for @vitest_dev 4.1 is out! 🧪 What's new: ◆ Chai-style spy assertions (`toHaveBeenCalled`, etc.) ◆ `userEvent.wheel()` for browser mode ◆ Enhanced retry options for flaky tests ◆ Disposable returned from `doMock()` ◆ Respecting coverage ignore start/stop hints ◆ and more 👀 Try now by installing vitest@beta
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New Year. New Look. Same Mission. Make JavaScript developers more productive than ever before
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Want to speed up subsequent @vitest_dev runs? Then try out the new experimental file-system based cache ✨ ⋄ Caches transformed modules ⋄ Does *not* work with browser mode yet ⋄ Can be manually cleared via `vitest --clearCache` More in the docs vitest.dev/config/experiment…
Vitest’s Experimental FS Cache Enable via CLI or config: `pnpm vitest --experimental.fsModuleCache` First run does not change timings. There is no cache yet! An image with statistics about the test run with 3088 tests passed and 6.17s testing duration, transform taking 5.32s, setup 461ms and collect 18.50s. Subsequent runs use the file system cache, reducing transform times Another statistics image. The subsequent run now takes only 5.14s, with transform time down to 673ms, setup to 341ms and collection time down to 13.20s

ALT Vitest’s Experimental FS Cache Enable via CLI or config: `pnpm vitest --experimental.fsModuleCache` First run does not change timings. There is no cache yet! An image with statistics about the test run with 3088 tests passed and 6.17s testing duration, transform taking 5.32s, setup 461ms and collect 18.50s. Subsequent runs use the file system cache, reducing transform times Another statistics image. The subsequent run now takes only 5.14s, with transform time down to 673ms, setup to 341ms and collection time down to 13.20s

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I started a proof of concept to integrate the standard schema natively into @vitest_dev It's currently being discussed integrating this directly into `toEqual()`, creating a new custom matcher like `toEqualSchema()` or an asymmetric matcher like `schemaMatching()`
Chris Cook
@zirkelc21 Aug 2025
What if we can turn `expect(url).toMatch(/^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$/)` into `expect(url).toMatchSchema(z.url())`? I created a custom matcher for @vitest_dev to validate data against any schema
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What's new in ViteLand? Our August 2025 recap is out 👣 Big steps for Oxlint: Type-aware linting preview & custom JS plugins roadmap 🖼️ @vitest_dev has visual regression support in beta ⏩ Native plugins enabled by default in rolldown-vite 🤌 Smaller bundles due to @rolldown_rs and Oxc 👀 and more
void(0) - What's New in ViteLand? August 2025 Recap

ALT void(0) - What's New in ViteLand? August 2025 Recap

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