ReturnValueMustNotBeNullAssertionScenarios

ReturnValueMustNotBeNullAssertionScenarios.fs

namespace ReturnValueMustNotBeNullAssertionScenarios

open FsCheck
open Ploeh.AutoFixture.Idioms.FsCheck
open Ploeh.AutoFixture.Kernel
open Ploeh.AutoFixture.Xunit
open System
open Xunit.Extensions

type Generators =
    static member Version() =
        Arb.generate<byte>
        |> Gen.map int
        |> Gen.four
        |> Gen.map (fun (ma, mi, bu, re) -> Version(ma, mi, bu, re))
        |> Arb.fromGen

module Foo =
    let bar (s : string, v : Version) =
        match v.Major with
        | ma when v.Major > 10 -> null
        | _                    -> Version(v.Major, v.Minor + 1, v.Build, v.Revision)

    [<Theory; AutoDataAttribute>]
    let ``bar query must not be null`` (builder : ISpecimenBuilder) =
        Arb.register<Generators>() |> ignore
        let methodInfo = bar.GetType().DeclaringType.GetMethod("bar")
        ReturnValueMustNotBeNullAssertion(builder).Verify(methodInfo)