FsCheck vs QuickTheories
FsCheck
fscheck.github.ioQuickTheories
github.comSide by side
| Figure | FsCheck | QuickTheories |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Windows | Yes | — |
| macOS | Yes | — |
| Linux | Yes | — |
| API | — | Yes |
| Self-hosted | — | Yes |
| Plans published | 1 | 1 |
| Spec score · Property-Based Testing Tools | 8.4 (#3) | 7.7 (#10) |
| Audience | FsCheck is for developers who want to test properties of .NET programs with generated inputs. | The README describes the library for Java developers who want to test general properties and invariants of their code. |
| Generators | Users can define custom test data generators and shrinkers, and package them together in Arbitrary instances. | Its generator DSL can create common Java types, constrain generated values, and combine or convert generators for custom types. |
| License | The project says its BSD license permits modification and redistribution for commercial and non-commercial purposes. | The repository identifies its license as Apache-2.0. |
| Purpose | FsCheck automatically tests .NET programs by checking properties against randomly generated cases. | QuickTheories is a property based testing library for Java 8, described as a Java version of QuickCheck. |
Plans
In their own words
FsCheck
FsCheck checks properties of.NET programs against randomly generated cases. Developers can express properties in F#, C# or VB, then run them with the built-in runner from an interactive session, a command-line program or a test framework. Integrations are documented for xUnit.net and NUnit, with user-created integrations for Expecto, Fuchu, AutoFixture and MSTest. When a property fails, FsCheck shrinks the input and shows a minimal counterexample. Developers can also define custom generators and shrinkers and group them in Arbitrary instances. The library supports parameterized cases and parallel execution, and its packages and NUnit and xUnit.NET plugins are available from NuGet. FsCheck is free: its listed plan is free, with a BSD license permitting commercial and non-commercial modification and redistribution. It runs on Linux, macOS and Windows. The project maintains version 3.x, but its documentation covers 2.x and is described as out of date and incomplete. Its model-based testing API is experimental and exempt from semantic-versioning guarantees.
QuickTheories
QuickTheories is a free, open-source property-based testing library for Java 8. It checks general properties and invariants by generating random valid inputs, then automatically searches for smaller or simpler values that still fail a property. The library reports the seed for a falsified property, and tests can use fixed seeds for deterministic runs. Its generator DSL creates common Java types, constrains values, and combines or converts generators for custom types. QuickTheories works with JUnit, TestNG, and other test frameworks; `checkAssert` supports assertion libraries such as AssertJ and Hamcrest. The `forAll` API handles theories over one to four generated values. System properties configure seeds, example counts, and shrink attempts, while named profiles can reuse settings. An experimental coverage feature targets new code paths, but may reduce performance by about 10% and interfere with JaCoCo or other coverage systems. The project uses the Apache-2.0 license.