QCheck vs Scala Hedgehog

QCheck is a property-based testing library for OCaml, inspired by QuickCheck. Rather than relying only on hand-picked examples, it provides combinators to generate values such as lists, arrays, tuples, recursive types, and algebraic types for checking properties. When a check fails, generators can be paired with printers and shrinkers to show and reduce counterexamples. QCheck2 builds shrinking into its generators, though the project describes that API as less battle-tested than QCheck. The package family includes qcheck-core, qcheck-ounit, qcheck-alcotest, qcheck, and ppx_deriving_qcheck; the last can derive generators from type declarations. Runner options include QCheck_base_runner in qcheck-core and QCheck_runner with OUnit compatibility in qcheck, with integration layers for OUnit and Alcotest. The project also points to qcheck-stm for sequential and parallel model-based tests and qcheck-lin for sequential consistency testing. Installation is available through opam, and the source can be built with make. The minimal qcheck-core package depends only on unix and dune. QCheck is free and licensed under BSD-2-Clause.

Scala Hedgehog is a property-based testing system for Scala that generates values to check properties and can simplify failing cases while preserving the generated values’ invariants. Range combinators let developers set the scope of generated numbers and collections. For stateful software, its abstract state machine testing can model systems such as web services and database layers. The project includes an SBT test runner and integration modules for Minitest and MUnit; its documentation also describes Gradle support through a Scala plugin. Documented Scala versions are 2.12, 2.13 and 3.3 or later. Binary dependencies for its modules are published through Maven Central, and the core module has no external dependencies. Scala Hedgehog is free, with no paid plans listed. The project describes its release as early and says its API may change before wider adoption. IntelliJ’s Scala plugin does not list Hedgehog among its built-in test frameworks, though Properties tests can be run as applications. The getting-started documentation assumes SBT; SBT 1.9.1 and later support the testing extension by default, while earlier versions require a testFrameworks setting.