/fsharp-hedgehog

Hedgehog will eat all your bugs.

Primary LanguageF#OtherNOASSERTION

fsharp-hedgehog NuGet Travis

Hedgehog will eat all your bugs.

Hedgehog is a modern property-based testing system, in the spirit of QuickCheck. Hedgehog uses integrated shrinking, so shrinks obey the invariants of generated values by construction.

Features

  • Integrated shrinking, shrinks obey invariants by construction.
  • Convenient syntax for generators and properties with gen and property expressions.
  • Range combinators for full control over the scope of generated numbers and collections.

Example

The root namespace, Hedgehog, includes almost everything you need to get started writing property tests with Hedgehog.

open Hedgehog

Once you have your import declaration set up, you can write a simple property:

let propReverse : Property<Unit> =
    property {
        let! xs = Gen.list (Range.linear 0 100) Gen.alpha
        return xs |> List.rev |> List.rev = xs
        }

You can then load the module in F# Interactive, and run it:

> Property.print propReverse
+++ OK, passed 100 tests.

More examples can be found in the tutorial.