Hypothesis vs ScalaCheck

Hypothesis is a free property-based testing library for Python. You describe behavior that your code should satisfy, and it generates inputs—including edge cases—to explore whether those properties hold. Strategies let you define and combine the data used in tests. When a failure appears, Hypothesis reports an example and tries to simplify it; failing examples are stored in a local test database for replay in later runs. Tests run as ordinary Python functions within pytest, unittest, nose, or another framework that can run a Python function. Hypothesis is not itself a test runner. By default, it generates 100 random inputs per test, and max_examples controls that count. Rule-based state machines can generate sequences of operations for testing stateful systems and objects. The project supports and tests CPython and PyPy 3.10 and later, and says it regularly works on Linux, macOS, Windows, and Emscripten. Its compatibility policy supports only the newest Hypothesis version; undocumented behavior may change in patch releases.

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.