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Property-based testing for JavaScript and TypeScript
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Illustration for Testing made easy

Testing made easy

Finding bugs has never been so easy! From classical edge cases to very complex combinations of inputs, fast-check is able to detect any class of bug.

Illustration for Test runner agnostic

Test runner agnostic

fast-check can be used within any test runner without any specific integration needed. It works well with Jest, Mocha, Vitest, and others.

Illustration for Next level testing

Next level testing

Let fuzzing and generative testing help you into uncovering the most challenging bugs: race conditions, prototype poisoning, zero-days…

They trust us…

These projects have been using fast-check for some time now and have found some issues thanks to it!

They contribute to the project…

People involved at some point in the development of fast-check

Avatar for Nicolas DUBIEN (dubzzz)Avatar for Aaron Elligsen (hath995)Avatar for Will Heslam (willheslam)Avatar for kazchimo (kazchimo)Avatar for Brandon Chinn (brandon-leapyear)Avatar for Irakli Safareli (safareli)Avatar for Andrew Herron (TheSpyder)Avatar for Eric Crosson (EricCrosson)Avatar for burrscurr (burrscurr)Avatar for JC (Jonathan Chen) (dijonkitchen)Avatar for Larry Botha (larrybotha)Avatar for Roman Gusev (102)Avatar for Tim Wisniewski (timwis)Avatar for Brais Piñeiro (brapifra)Avatar for Renaud-Pierre Bordes (brds)Avatar for Jemma Nelson (fwip)Avatar for John Haugeland (StoneCypher)Avatar for Trey Davis (treydavis)Avatar for Leon Si (leonzalion)Avatar for Gorgi Kosev (spion)Avatar for mayconsacht (mayconsacht)Avatar for Simon Friis Vindum (paldepind)Avatar for Richard Gibson (gibson042)Avatar for Alan Harper (aussiegeek)Avatar for Makien Osman (Osman-Sodefa)Avatar for David Sommerich (sommd)Avatar for Diego Pedro (diegopedro94)Avatar for Borui Gu (BoruiGu)Avatar for Brian Donovan (eventualbuddha)Avatar for volrk (volrk)Avatar for tinydylan (tinydylan)Avatar for Caleb Jasik (jasikpark)Avatar for Rulai Hu (rulai-hu)Avatar for Afonso Jorge Ramos (afonsojramos)Avatar for Tom Jenkinson (tjenkinson)Avatar for phormio (phormio)Avatar for Giovanni Gonzaga (giogonzo)Avatar for Tomas Carnecky (wereHamster)Avatar for Kirill Romanov (Djaler)Avatar for Giovanny González (giovannyg)Avatar for Mark Kulube (markkulube)Avatar for Peter Hamilton (hamiltop)Avatar for Chinedu Ozodi (ChineduOzodi)Avatar for Gunar Gessner (gunar)Avatar for Christian Batchelor (CSBatchelor)Avatar for Tomer Aberbach (TomerAberbach)Avatar for 0xflotus (0xflotus)Avatar for Ryan Leonard (CodeLenny)Avatar for Jason Dreyzehner (bitjson)Avatar for Matin Zadeh Dolatabad (matinzd)Avatar for Juan Julián Merelo Guervós (JJ)Avatar for Simen Bekkhus (SimenB)Avatar for Tarjei Skjærset (tskj)Avatar for Denis Gorbachev (DenisGorbachev)Avatar for Trevor McCauley (senocular)Avatar for Grant Kiely (gkiely)Avatar for Attila Večerek (vecerek)Avatar for Zach Bjornson (zbjornson)Avatar for Bennett Perkins (bennettp123)Avatar for Alexandre Oger (nielk)Avatar for ej shafran (ej-shafran)Avatar for Niklas Gruhn (gruhn)Avatar for Patrick Roza (patroza)Avatar for Cindy Wu (cindywu)Avatar for Noah (nmay231)

They sponsor us…

They financially contribute to the fast-check

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You can also become one of them by contributing via GitHub Sponsors or OpenCollective.