--- title: New falsify release | daily.dev description: falsify 0.4.0 has been released, a property-based testing library for Haskell inspired by Python's Hypothesis. The main new feature is a `Context` type in the... canonical: https://daily.dev/posts/new-falsify-release-szppwlbeg twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: New falsify release | daily.dev og:description: falsify 0.4.0 has been released, a property-based testing library for Haskell inspired by Python's Hypothesis. The main new feature is a `Context` type in the... og:url: https://daily.dev/posts/new-falsify-release-szppwlbeg og:image: https://api.daily.dev/og/posts/SzppWlbeG.png og:image:alt: New falsify release og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # New falsify release **[Planet Haskell](https://daily.dev/sources/phaskell)** · 5 min read · 0 upvotes · 0 comments ## Summary falsify 0.4.0 has been released, a property-based testing library for Haskell inspired by Python's Hypothesis. The main new feature is a `Context` type in the `Property` monad, exposing how many tests are being run and which iteration is current — enabling size-aware test generation via a new `sized` convenience function. The release also includes significant cleanup: tasty integration is now a separate `tasty-falsify` package, the module hierarchy has been reorganized (new `Data.Falsify.*` modules), deprecated functions removed, and some type aliases replaced with newtypes. The post also compares falsify to QuickCheck and Hedgehog, noting falsify solves the monadic bind cut-point shrinking problem but is still experimental compared to those more battle-tested libraries. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Issue 534](https://daily.dev/posts/issue-534-rpp60utgy) · Haskell Weekly · 0 upvotes · 0 comments - [Hypothesis, Antithesis, synthesis](https://daily.dev/posts/hypothesis-antithesis-synthesis-adkxphviv) · Hacker News · 1 upvotes · 0 comments - [A testing conundrum](https://daily.dev/posts/a-testing-conundrum-3xscbuqqt) · Planet Python · 3 upvotes · 0 comments - [Cure, Four Releases Deep: From FSMs to Furniture](https://daily.dev/posts/cure-four-releases-deep-from-fsms-to-furniture-t6xybgdfg) · Beam Bloggers Webring · 0 upvotes · 0 comments - [Let Hypothesis Break Your Python Code Before Your Users Do](https://daily.dev/posts/let-hypothesis-break-your-python-code-before-your-users-do-cjc2gqyor) · Towards Data Science · 0 upvotes · 0 comments --- Tags: [#haskell](https://daily.dev/tags/haskell) [View this post on daily.dev](https://daily.dev/posts/new-falsify-release-szppwlbeg) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"New falsify release","url":"https://daily.dev/posts/new-falsify-release-szppwlbeg","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/new-falsify-release-szppwlbeg"},"datePublished":"2026-07-17T08:34:03.084Z","dateModified":"2026-07-17T08:34:27.980Z","description":"falsify 0.4.0 has been released, a property-based testing library for Haskell inspired by Python's Hypothesis. 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