🎲 Property-based testing for JavaScript and TypeScript compatible with Vitest, Jest and others · Official website at https://fast-check.dev · Made with ♥️ by @nicolas.dubien.mehttps://blacksky.community/profile/fast-check.devhttps://blacksky.community/profile/fast-check.dev/post/3mp524uox5c2iFresh new version of pure-rand, our backing library powering every random value we generate in fast-check. https://npmx.dev/package/pure-rand25 Jun 2026 18:18 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mp524uox5c2ihttps://blacksky.community/profile/fast-check.dev/post/3mofbg6rqg22aThe next minor is being worked on. Expect a few performance optimisations to land ⚡16 Jun 2026 07:25 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mofbg6rqg22ahttps://blacksky.community/profile/fast-check.dev/post/3ml2beikt7c2e🐒 And now it's fast-check's turn at https://tangled.org/fast-check.dev/fast-check So far, just mirrors of @github.com on @tangled.org but stability of GitHub is more and more concerning 😟 [contains quote post or other embedded content]04 May 2026 18:09 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3ml2beikt7c2ehttps://blacksky.community/profile/fast-check.dev/post/3ml2556v2gk2g🎲 We just started to mirror pure-rand on @tangled.org https://npmx.dev/package/pure-rand04 May 2026 16:53 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3ml2556v2gk2ghttps://blacksky.community/profile/fast-check.dev/post/3mjsjyeuogk2f🚀 fast-check 4.7.0 has recently been released! ✍️ Support for unicode properties in `stringMatching` 🗜️ Reversible values with `json` More details at https://fast-check.dev/blog/2026/04/18/whats-new-in-fast-check-4-7-0/18 Apr 2026 22:57 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mjsjyeuogk2fhttps://blacksky.community/profile/fast-check.dev/post/3mhzublrzc22o🚀 We just released a fresh way lighter version of pure-rand. Install size for each recent version: • 𝟴.𝟰.𝟬: 62.4 kB 🐇 • 𝟴.𝟯.𝟬: 71.6 kB 🐘 • 𝟴.𝟮.𝟬: 53.6 kB 🐜 [contains quote post or other embedded content]27 Mar 2026 09:59 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mhzublrzc22ohttps://blacksky.community/profile/fast-check.dev/post/3mhzhthdufk2c🖇️ Our latest release of @fast-check/vitest added native support for before each/afterEach hooks of @vitest.dev. No more need to manually connect them into fast-check assertions they get automatically integrated if you use our connector package. Connector: https://npmx.dev/package/@fast-check/vitest27 Mar 2026 06:16 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mhzhthdufk2chttps://blacksky.community/profile/fast-check.dev/post/3mhzheypxs22c🗜️ We are working on a new release of pure-rand to decrease the bundle impact of our Mersenne Twister jump 🤫 📚 And on fast-check's side we pile a few ideas for a next major that should bring an even faster runtime and more. [contains quote post or other embedded content]27 Mar 2026 06:08 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mhzheypxs22chttps://blacksky.community/profile/fast-check.dev/post/3mhi3nbo7nc2h🎲 New release of pure-rand, our internal dependency. With 33% increase in bundle size but for the right cause: we want to provide users with ways to jump on Mersenne Twister generators. It has been a long PR started 6 years ago and that finally made it.20 Mar 2026 08:23 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mhi3nbo7nc2hhttps://blacksky.community/profile/fast-check.dev/post/3mgnzj7mg4k2l⚡ fast-check 4.6.0 is here! It comes with: 🗜️ Lighter bundle 🔧 Extra capabilities for stringMatching More details at https://fast-check.dev/blog/2026/03/09/whats-new-in-fast-check-4-6-0/09 Mar 2026 23:36 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mgnzj7mg4k2lhttps://blacksky.community/profile/fast-check.dev/post/3mgdsuymiec2x🚀 This is it: version 8.0.0 of pure-rand is out! 📦 Lighter bundle 🛢️ No more barrel files 🧹 Simplified API by default https://npmx.dev/package/pure-rand05 Mar 2026 22:10 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mgdsuymiec2xhttps://blacksky.community/profile/fast-check.dev/post/3mgdnx6b2wk2s👋 Welcome from @eurosky.social05 Mar 2026 20:42 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mgdnx6b2wk2shttps://blacksky.community/profile/fast-check.dev/post/3mfvxbkoxr22g🎲 We are currently making deep changes onto our internal random library called pure-rand. Expects lighter bundle on npm and faster to load at execution time within fast-check28 Feb 2026 09:52 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mfvxbkoxr22ghttps://blacksky.community/profile/fast-check.dev/post/3mfrwhmzzss2v🏃‍♂️ Currently updating all our links to point to @npmx.dev · PRs on their way to update our website fast-check.dev but also all the README files https://fast-check.dev/26 Feb 2026 19:27 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mfrwhmzzss2vhttps://blacksky.community/profile/fast-check.dev/post/3mfjpcfbre22a🤯 Still impressed to see how simple it is to move from Jest to @vitest.dev We just moved pure-rand, one of the core packages in fast-check23 Feb 2026 12:57 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mfjpcfbre22ahttps://blacksky.community/profile/fast-check.dev/post/3mfjcsfai5c2a⚡ We are currently moving our build chain to @rolldown.rs It's a game changer! Our packages are building really fast now. In the past we were using raw Typescript, but it's not an ideal option to bundle a package even if it works pretty well.23 Feb 2026 09:13 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mfjcsfai5c2ahttps://blacksky.community/profile/fast-check.dev/post/3mfarhqxkrs2o⁉️ Is this GitHub action workflow risky? With pull_request alone I have to wait for having manually approved the workflows to run on the PR, pull_request_target seems to be the way to go, but I'm uncomfortable with using it 😬 Anyone to confirm it's safe? https://github.com/dubzzz/fast-check/blob/copilot%2Fensure-pr-template-check-action/.github%2Fworkflows%2Fpr-template-check.yml19 Feb 2026 23:42 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mfarhqxkrs2ohttps://blacksky.community/profile/fast-check.dev/post/3mfafw5zxcc2u🔑 We've just reworked our template for pull requests on @fast-check.dev With the rise of vibe-coding we wanted to take into account this new trend in our checklist that must be completed before opening a PR: https://github.com/dubzzz/fast-check/blob/4e153cca78efd99aab24890d1dcfa80508748bf0/.github/PULL_REQUEST_TEMPLATE.md19 Feb 2026 20:15 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mfafw5zxcc2uhttps://blacksky.community/profile/fast-check.dev/post/3me32zmew722fWe are currently deeply reworking our JavaScript testing expert to make it able to deal with a larger variety of tests 🤞 Several new guidelines will be added to help AI agents into proofreading the test they wrote to be critical of themselves before giving you the test. [contains quote post or other embedded content]04 Feb 2026 23:52 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3me32zmew722fhttps://blacksky.community/profile/fast-check.dev/post/3mdzvglj76k2fSpread love 💕 Like us on @npmx.dev, https://npmx.dev/package/fast-check04 Feb 2026 12:39 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mdzvglj76k2fhttps://blacksky.community/profile/fast-check.dev/post/3mdx2rbw67k2dWe are now part of @npmx.dev testing tool-chain. More tests to come. [contains quote post or other embedded content]03 Feb 2026 09:37 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mdx2rbw67k2dhttps://blacksky.community/profile/fast-check.dev/post/3mds3uwca5k2s👉 Our testing expert is there: https://skills.sh/dubzzz/fast-check/javascript-testing-expert We will restrict the scope to non-e2e but plan to cover testing-library and playwright. 🙏 Help welcomed ♥️ Share the word and feel free to contribute, the more contributors the better the rules [contains quote post or other embedded content]01 Feb 2026 10:13 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mds3uwca5k2shttps://blacksky.community/profile/fast-check.dev/post/3mdr62andgc2j🚀 Here is a very first version of our "JavaScript testing expert". There are still a LOT of missing guidelines. We still want to cover basics of UI testing with testing-library and @vitest.dev with @playwright.dev but soon... First let's play with it 🤞 [contains quote post or other embedded content]01 Feb 2026 01:19 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mdr62andgc2jhttps://blacksky.community/profile/fast-check.dev/post/3mdqagtdvbc2j🧙‍♂️ We are currently writing down some AI skills for testing in general and some for fast-check itself Hope it could lead to better tests and less bugs 👾31 Jan 2026 16:29 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mdqagtdvbc2jhttps://blacksky.community/profile/fast-check.dev/post/3mdmwc2f4s22c🤫 We’re cleaning up our packages and going ESM-only. Reworking the entire build pipeline, moving from pure tsc to Rolldown. 😍 @rolldown.rs is so easy to connect. Amazing how quickly you can get what you need with just a few lines.30 Jan 2026 08:50 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mdmwc2f4s22chttps://blacksky.community/profile/fast-check.dev/post/3mde2fndrm22lWe’re excited to welcome Mercedes-Benz as a new sponsor of fast-check! 🚀26 Jan 2026 20:09 +0000at://did:plc:tq4phsnpdiqp67hpqjwrniri/app.bsky.feed.post/3mde2fndrm22l