FsCheck vs PropEr
FsCheck
fscheck.github.ioPropEr
proper-testing.github.ioSide by side
| Figure | FsCheck | PropEr |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Windows | Yes | — |
| macOS | Yes | — |
| Linux | Yes | — |
| Self-hosted | — | Yes |
| Plans published | 1 | 1 |
| Spec score · Property-Based Testing Tools | 8.4 (#3) | 7.5 (#14) |
| Installation | FsCheck and its NUnit and xUnit.NET plugins can be installed from NuGet. | The user guide describes obtaining source from GitHub, compiling it with make, or installing it with Homebrew. |
| Integrations | The project documents integrations with xUnit.net and NUnit, and user-created integrations with Expecto, Fuchu, AutoFixture and MSTest. | The user guide explains using PropEr with EUnit and describes handling a shared ?LET macro and captured output. |
| License | The project says its BSD license permits modification and redistribution for commercial and non-commercial purposes. | PropEr is open-source software distributed under the GPL, version 3 or later. |
| Purpose | FsCheck automatically tests .NET programs by checking properties against randomly generated cases. | PropEr is a tool for automated, semi-random, property-based testing of Erlang programs. |
| Stateful testing | Model-based testing for stateful systems and objects is in the Experimental namespace, where semantic-versioning promises do not apply. | It can also be used for model-based random testing of stateful systems. |
| Support | The project invites users to report issues on GitHub and says contributors may open issues about documentation problems or gaps. | The developers invite comments, suggestions, feature requests, bug reports, patches, and other contributions through the project website, GitHub, or email. |
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.
PropEr
PropEr is a free, open-source testing tool for Erlang programs. It performs automated, semi-random property-based testing and can generate input data from Erlang type declarations. Functions can be tested automatically from information in their Erlang specifications, while properties are written as Erlang expressions with predefined macros. PropEr also supports model-based random testing for stateful systems and targeted property-based testing using search-based techniques. Failing cases can be shrunk, and the project supports EUnit and Common Test. Constraints that Erlang’s type language cannot express can be handled with custom generators; filtering may keep trying random values until one passes. The generator language differs from Erlang’s type language for list expressions, including support for particular list lengths and element types. PropEr is self-hosted, supports Erlang, and is distributed under GPL version 3 or later. The guide describes installation from GitHub source, with make, or through Homebrew.