PropCheck vs ScalaCheck

PropCheck is a Ruby library for property-based testing: it generates inputs and checks whether assertions hold across them. When a generated example fails, it tries to simplify that case into a smaller counterexample. Built-in generators cover integers, floats, strings, symbols, arrays, hashes, sets, dates, times and datetimes. A generator DSL lets developers define their own, while the API also supports mapping and binding values, alternatives and weighted frequency choices.

Before, after and around hooks provide setup and cleanup around generated examples. The README gives usage examples for RSpec, MiniTest, test-unit and vanilla Ruby, and says the library has no external dependencies. PropCheck requires Ruby 2.5.1 or later and is released under the MIT License. It is available as a free Community library. Installation can be done through a Gemfile or with `gem install prop_check`. For generated examples involving a database, the README recommends cleaning database state around each example and mentions DatabaseCleaner. Stateful property testing is described as a possible future separate add-on.

ScalaCheck is a free Scala library for automated property-based testing of Scala and Java programs. It checks defined properties against randomized input parameters and reports the arguments that produce a failure. The library supports parameterized cases and parallel execution, and can run on its own with a built-in test runner. For sbt projects, the site shows how to add it as a test dependency; it is also integrated with ScalaTest, specs2 and LambdaTest. ScalaCheck has no external dependencies beyond the Scala runtime. Build artifacts are published in the Central Repository, with an sbt dependency declaration available from the download page. Documentation includes a user guide and API reference. The site lists version 1.19.0, released September 6, 2025. The project identifies the BSD-3-Clause license and lists a security policy. Its build defines JVM, Scala.js and Scala Native platforms, and its README says the Gradle plugin supports Scala.js and Scala Native. The site names the Scala compiler and Akka among projects that use it.