fsharp.md

Usage in FSharp

NullValueHandling

By default DefaultValueHandling is Ignore. Since F# Option.None is treated as null, it will be ignored by default. To include Option.None use VerifierSettings.AddExtraSettings at module startup:

VerifierSettings.AddExtraSettings(fun settings -> settings.NullValueHandling <- NullValueHandling.Include)

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Async Qwerks

F# does not respect implicit operator conversion. SettingsTask uses implicit operator conversion to provide a fluent api in combination with an instance that can be awaited. As such SettingsTask.ToTask() needs to be awaited when used inside F#.

[<Fact>]
let MyTest () =
    async { do! Verifier.Verify(15).ToTask() |> Async.AwaitTask }

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Tasks can also be used directly via a task computation expression builder, such as the ones included in Ply, TaskBuilder.fs, or (starting with F# 6.0) FSharp.Core:

[<Fact>]
let MyTaskTest () = task { do! Verifier.Verify(15) }

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Full tests

[<VerifyXunit.UsesVerify>]
module Tests

open Xunit
open VerifyTests
open VerifyXunit
open Newtonsoft.Json

VerifierSettings.AddExtraSettings(fun settings -> settings.NullValueHandling <- NullValueHandling.Include)

[<Fact>]
let MyTest () =
    async { do! Verifier.Verify(15).ToTask() |> Async.AwaitTask }

[<Fact>]
let MyTaskTest () = task { do! Verifier.Verify(15) }

[<Fact>]
let WithFluentSetting () =
    async {
        do!
            Verifier
                .Verify(15)
                .UseMethodName("customName")
                .ToTask()
            |> Async.AwaitTask
    }
do ()

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