The page at https://code.google.com/p/fsunit/ says the project has been moved to CodePlex, then the codeplex page points here. Would be nice to change https://code.google.com/p/fsunit/ to point straight here.

It would be nice to add something like Phil Trelford's spy function from this article:

• http://trelford.com/blog/post/Stubs.aspx

With FsUnit, as seen in the documentation, a unit test is written:

actual |> should equal expectedValue

We can verify by looking at the source code of Nunit's EqualityConstraint that indeed equal should be given the expected value.

The documentation for FsUnitTyped is a little sparse, but it still seems to follow the pattern "actual on the left; expected on the right".

However, if we look at the source code of shouldEqual in FsUnitTyped, we can see that it is defined with expected as the first argument and actual as the second.

So actual |> shouldEqual expectedValue will (on failure) print out:

Expected: actual
Actual: expected

I'm not sure if the arguments are flipped for the other functions in FsUnitTyped or if this just affects shouldEqual. I haven't used any of the others.

Pretty please? Is there anything to do here beyond bumping the version?

I'm using version 1.3.0.1, the latest version available from NuGet, It's missing the choice matcher in #39, but it is described in the documentation as a feature.

using xunit

list2 |> Seq.iter (list1 |> (should contain) ) does not work

however list2 |> Seq.iter (fun x - > list1 |> should contain x) does

(list |> should contain) returns a function of type object -> unit so I do not understand why I get a match exception.

Builds, but fails at run time.

let result = 
    ["est"; "1test"; "est1"] 
    |> Set.ofList

x'.Value |> should equal result

nunit.framework.dll 3.0.5813.39031
FsUnit.NUnit.dll 2.0.0.0

Assert.AreEqual(x'.Value, result) works

Based on this SO question, I think that adding function isUnionCase would be pretty useful for testing.

(Or similar functionality exposed in some nicer FsUnit-friendly way, like should (beCase <@ Foo @>))

Hi,

We have an F# code base in Visual Studio 2012 and would like to support MonoDevelop 3.0 as well. On Mono, the core is running fine but our test cases written in FsUnit/NUnit failed before running (therefore we couldn't verify its correctness). We used NuGet to manage packages both in Visual Studio and MonoDevelop.

Configuration: Mono 3.0.2/F# 3.0, MonoDevelop 3.0 on Mac OS X Lion

Here is a simple repro:

1. Use the LightBulb example from the home page
2. Retrieve FsUnit.NUnit 1.1.0.2 and NUnit 2.6.2 via NuGet
3. Run unit tests by default test runner in MonoDevelop
4. All the tests fail with the same exception:

System.MissingMethodException : Method not found: 'FsUnit.equal'.

  at FsUnit.should[String,EqualConstraint] (Microsoft.FSharp.Core.FSharpFunc`2 f, System.String x, System.Object y) [0x00000] in <filename unknown>:0 
  at FsUnitSupport.Given a LightBulb that has had its state set to false.when I convert it to a string it becomes "Off". () [0x0004b] in /path/to/Test.fs:36 
  at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (System.Reflection.MonoMethod,object,object[],System.Exception&)
  at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0 

A similar attempt by downloading FsUnit.NUnit.dll and nunit.framework.dll directly from the master branch didn't succeed.
FYI, a simple test project with NUnit alone worked fine.

Thanks,

https://xunit.github.io/release-notes/2017-02-19.html

Currently, you have to use ignore to discard the result in the function and you need to get type using typeof:

(fun () -> failwith "BOOM!" |> ignore) |> should throw typeof<System.Exception>

I think it would be neat if you could write just:

(fun () -> failwith "BOOM!") |> should throw<System.Exception>

Description

The latest NuGet package for FsUnit (2.3.2) uses an out-of-date NUnit (3.5), so you can't use FsCheck.NUnit together with it, since it requires NUnit 3.6-or-greater.

The FSunit nuget fetches the latest Xunit on install. FSunit breaks in fascinating ways (unable to load assembly) when the Xunit version is not correct.
I tried to do the upgrade myself and deliver this request as a pull req, but apparently Nuget and F# are not very good friends, and I had to throw in the towel...

When FSUnit is added to a project via nuget, the sample .fs file is formatted in such a way that the compiler assumes verbose syntax. (For example if you add lines you need to add 'in' to the end of every line.) The sample should be created so that light syntax is assumed. This is just a matter of changing the tabbing/newlines slightly.

the example as below. If I don't remove the type annotation, how can I make it success?

open NUnit.Framework
open FsUnit

let id (a: int * string list) = a

[<Test>]
let ``test id`` () =
    let a = (0, [])
    id a |> should equal a

//cc @tpetricek original request

@tpetricek @forki Why you do not like reference package from NuGet?

ToString() on values that failed equality assertion is often quite useless, can we have "%A" formatter applied instead?

If I create a new F# library project based on .NET Framework 4.7 and add the FsUnit 3.0.0 nuget package, I get a lot of additional nuget packages, supporting .net standard library 1.6.

My expectation would be that the FsUnit package targeted more than just .net standard 1.6, for instance .NET Framework 4.6 in addition. That way, I would only get FsUnit and not 40+ other packages as well.

Description

FsUnit is locked to exactly v3.2.0 of NUnit, but there has been a 3.2.1 release that seems to work fine with an app.config redirect - but you have to force NuGet to ignore dependencies to install it.

I think it would be preferable if FsUnit accepted v3.2.* so FsUnit doesn't have to keep step with the releases in NUnit.

Just tried these on 1.3.0.1 and both are throwing null ref exception
"123" |> should be null
"123" |> should not' (be null)
null |> should be null

using Nunit's Assert.That(null, Is.Null) works

1. Building c:\sources\FsUnit\src\FsUnit.Xunit\FsUnit.Xunit.fsproj failed with exitcode 1.
2. FS0219: c:\sources\FsUnit\src\FsUnit.Xunit\unknown(1,1): The referenced or default base CLI library 'mscorlib' is binary-incompatible with the referenced F# core library 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\FSharp.Core\v4.0_4.3.1.0__b03f5f7f11d50a3a\FSharp.Core.dll'. Consider recompiling the library or making an explicit reference to a version of this library that matches the CLI version you are using.
3. FS0229: c:\sources\FsUnit\src\FsUnit.Xunit\unknown(1,1): Error opening binary file 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\FSharp.Core\v4.0_4.3.1.0__b03f5f7f11d50a3a\FSharp.Core.dll': The referenced or default base CLI library 'mscorlib' is binary-incompatible with the referenced F# core library 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\FSharp.Core\v4.0_4.3.1.0__b03f5f7f11d50a3a\FSharp.Core.dll'. Consider recompiling the library or making an explicit reference to a version of this library that matches the CLI version you are using.

1. Create a new F# Library project
2. From Package Manager Console, Install-Package FsUnit.xUnit
3. Run Test(s) (using TestDriven.NET)

------ Test started: Assembly: Library1.dll ------

Test 'Library1.Tests.Given a LightBulb that has had its state set to true.when I convert it to a string it becomes "On".' failed:
System.IO.FileLoadException : Could not load file or assembly 'NHamcrest, Version=1.2.1.0, Culture=neutral, PublicKeyToken=31c3ea0b6fcf8c4a' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)
at Library1.Tests.Given a LightBulb that has had its state set to true.when I convert it to a string it becomes "On".()

Test 'Library1.Tests.Given a LightBulb that has had its state set to true.when I ask whether it is On it answers true.' failed:
System.IO.FileLoadException : Could not load file or assembly 'NHamcrest, Version=1.2.1.0, Culture=neutral, PublicKeyToken=31c3ea0b6fcf8c4a' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)
at Library1.Tests.Given a LightBulb that has had its state set to true.when I ask whether it is On it answers true.()

0 passed, 2 failed, 0 skipped, took 2.01 seconds (xUnit.net 1.9.1 build 1600).

Are there any reasons not to add an overload that calls the function?

TestContext.AddFormatter(ValueFormatterFactory(fun _ -> ValueFormatter(sprintf "%A")))

depends on https://github.com/nunit/nunit/milestones/3.2
implemented in nunit/nunit#1196

it is not able to find Xunit asserts , asking for adding xunit library which is already added.

https://www.nuget.org/packages/MSTest.TestFramework/

I created a new F# Portable Library project and tried to add FsUnit via NuGet. I got this message:

Could not install package 'FsUnit 1.3.0.1'. You are trying to install this package into a project that targets 'portable-net45+win', but the package does not contain any assembly references or content files that are compatible with that framework. For more information, contact the package author.

Hi,

Is it possible to move the sample into a separate Nuget package? Or, alternatively, provide a Nuget package without the sample file?

I use FsUnit in many projects, and whilst the sample is useful for someone starting out with FsUnit it has become problematic for us as every time I add FsUnit to a new project or update existing projects I have to go through and delete the sample.

Thanks,

Just installed latest from NuGet, and even though the package path is 1.1.0.2 (packages\FsUnit.1.1.0.2\Lib\Net40) the dll itself (FsUnit.NUnit) is version 1.1.0.0 and it is dependent on NUnit Version=2.6.0.12051 and does not work with the latest NUnit 2.6.2

Steps to reproduce:

install-package fsunit

module test.mod
open NUnit.Framework
open FsUnit
let [<Test>] smoke () = 1 |> should equal 1

Have ReSharper 7.1 installed. Rightclick test project, select 'Run Unit Tests':

System.MissingMethodException : Method not found: 'Void FsUnit.TopLevelOperators.should(Microsoft.FSharp.Core.FSharpFunc`2<!!0,!!1>, !!0, System.Object)'.
   at test.mod.smoke()

Further testing done: downgrading NUnit to v2.6.2 from installing version 2.6.3.

This trivial test won't pass:

    [<Test>]
    member this.``structural equality``() =
        let actualList: char list = []
        [(actualList, "")] |> should equal [([], "")]

It fails with the interesting error:

Expected: [([], "")],
but was [([], "")]

However, it works correctly in FSI:

> let actualList: char list = [];;
   val actualList : char list = []
> [(actualList, "")] = [([], "")];;
   val it : bool = true

Why doesn't haveLength work with Seq?

Error is System.ArgumentException : Property Length was not found

Related information

macOS, FsUnit.Xunit 1.4.1

The following expression should not type check

1 |> should equal "hi"

//cc @tpetricek tweet

My parser tests all look like the following (I've defined the zero function locally so you can easily add it to your tests. This works fine in FsUnit.NUnit, but when I tried to move over to FsUnit.XUnit, I get a NullReferenceException. I would expect tests to work the same between the different flavors of FsUnit

    [<Test>] member test.
     ``non-null should not be None`` ()=
        let zero : 'input -> ('result * 'input) option = fun input -> None in 
        zero "something" |> should equal None

Description

Is there any chance to support other platforms than net45?
It would be nice to be able to add FsUnit to PCL, Xamarin, etc. projects?
I'd gladly give you a hand, too.

Repro steps

Create a PCL/Xamarin.iOS/Xamarin.Android/.. project and try add FsUnit as a nuget package.

Program:

open FsUnitTyped
open NUnit.Framework

1 |> shouldEqual 2
1 |> shouldNotEqual 2

Output:

NUnit.Framework.AssertionException:   Expected: 2\nActual: 1
  Expected: True
  But was:  False

What bothers me is that \n that is printed as a part of the actual string. This is my first time using both FsUnit and NUnit, but that can't be right.

Description

I get this error:
The type referenced through 'NUnit.Framework.Constraints.Constraint' is defined in an assembly that is not referenced. You must add a reference to assembly 'nunit.framework'.

Repro steps

Installed as per the instructions.

Visual Studio 2017
FsUnit 3.0.0
nunit 3.6.0

    open NUnit.Framework
    open FsUnit
    1 |> should equal 1

this fails with the above error but

    Assert.AreEqual(1,1)

works fine.

This relates to these issues:
#22

and
#10

I am still getting the null ref exception when attempting to do a |> should equal (None).

I believe the Nuget package FsUnit.xUnit is dependending on an old version of FsUnit.CustomMatchers.dll.

I verified by inspecting the assembly downloaded via nuget. The pre #22 code is still there.

   public static CustomMatcher<object> equal(object x)
    {
      return new CustomMatcher<object>(PrintfModule.PrintFormatToStringThen<FSharpFunc<string, string>>((PrintfFormat<FSharpFunc<string, string>, Unit, string, string>) new PrintfFormat<FSharpFunc<string, string>, Unit, string, string, string>("Equals %s")).Invoke(x.ToString()), new Func<object, bool>(new CustomMatchers.equal\u00408(x).Invoke));
    }

We definitely should create two new guild for FsUnit site

• FsUnit + FxCheck + NUnit
• FsUnit + FsCheck + XUnit

// sideeffffect/FSharpHello#1 (comment)

Right now, I'm using a match ... with clause with the pattern I want (e.g. I don't care about all the items in a tuple) manually.

    match f() with
    | _, _, _, 42 -> true
    | _ -> false
    |> should equal true

which is very clumsy. Is there a better way to do this currently?

In Eunit, I'd use ?assertMatch which uses macros (which we don't have in F#), is there some way to achieve the same effect in F#?

This code does not pass:

[<TestFixture>] 
type ``Given a invalid connection string`` () =
    let connstr = @"lkjljlj"

    [<Test>] member x.
        ``An argument exception will be thrown.`` () = 
            connstr |> parseConnStrToRavenConn |> should throw typeof<System.ArgumentException>

Code throws a System.ArgumentException and, thus, should pass.

In an earlier version, there used to be shouldEqual primitive that beahaved like y |> should equal x but statically required x and y to have the same type.

I find that extremely useful - I was using some untyped equal constraints and it quite regularly caused trouble where test would compile, but fail - when I changed some API.

Can we have this function (or some alternative) back?

We are using it in a signed assembly and it cannot be loaded otherwise

following 3 MbUnit tests are failing:

1. Seq with 1 item should fail to have Count 1
2. Seq with 1 item should fail to have Length 1
3. shouldFaild should throw an exception

here is the complete execution log for failing tests:

FsUnit.MbUnit.Test 
Passed0Failed3Inconclusive or Skipped0
Duration: 0.393s, Assertions: 6.
File: D:\My\Projects\tmp\2\FsUnit-master\tests\FsUnit.MbUnit.Test\bin\Release\FsUnit.MbUnit.Test.DLL
CodeBase: D:\My\Projects\tmp\2\FsUnit-master\tests\FsUnit.MbUnit.Test\bin\Release\FsUnit.MbUnit.Test.DLL
Version: 0.0.0.0
Framework: MbUnit v3.4 build 11
have Count tests 
Passed0Failed1Inconclusive or Skipped0
Duration: 0.326s, Assertions: 2.
Seq with 1 item should fail to have Count 1 

Duration: 0.296s, Assertions: 2.
An exception occurred while verifying an assertion.

System.ArgumentException: Property Count was not found
Parameter name: name
ParamName: name
   at FsUnit.CustomMatchers.op_Dynamic[Source,Result](Source this, String name) in D:\My\Projects\tmp\2\FsUnit-master\src\FsUnit.Xunit\CustomMatchers.fs:line 118
   at [email protected](Object arg) in D:\My\Projects\tmp\2\FsUnit-master\src\FsUnit.Xunit\CustomMatchers.fs:line 123
   at NHamcrest.CustomMatcher`1.Matches(T item) in C:\Documents and Settings\Graham\My Documents\NHamcrest\NHamcrest\CustomMatcher.cs:line 28

   at <StartupCode$FsUnit-MbUnit-Test>.$HaveCountTests.Seq with 1 item should fail to have Count [email protected](Unit unitVar0) in D:\My\Projects\tmp\2\FsUnit-master\tests\FsUnit.MbUnit.Test\haveCountTests.fs:line 32
   at [email protected](Object arg) in D:\My\Projects\tmp\2\FsUnit-master\src\FsUnit.Xunit\CustomMatchers.fs:line 29
   at NHamcrest.CustomMatcher`1.Matches(T item) in C:\Documents and Settings\Graham\My Documents\NHamcrest\NHamcrest\CustomMatcher.cs:line 28
   at FsUnit.Test.have Count tests.Seq with 1 item should fail to have Count 1() in D:\My\Projects\tmp\2\FsUnit-master\tests\FsUnit.MbUnit.Test\haveCountTests.fs:line 32

Expected System.ArgumentException

Expected : System.ArgumentException
But      : was <StartupCode$FsUnit-MbUnit-Test>.$HaveCountTests+Seq with 1 item should fail to have Count 1@32

   at FsUnit.Test.have Count tests.Seq with 1 item should fail to have Count 1() in D:\My\Projects\tmp\2\FsUnit-master\tests\FsUnit.MbUnit.Test\haveCountTests.fs:line 32

haveLength tests 
Passed0Failed1Inconclusive or Skipped0
Duration: 0.011s, Assertions: 2.
Seq with 1 item should fail to have Length 1 

Duration: 0.007s, Assertions: 2.
An exception occurred while verifying an assertion.

System.ArgumentException: Property Length was not found
Parameter name: name
ParamName: name
   at FsUnit.CustomMatchers.op_Dynamic[Source,Result](Source this, String name) in D:\My\Projects\tmp\2\FsUnit-master\src\FsUnit.Xunit\CustomMatchers.fs:line 118
   at [email protected](Object arg) in D:\My\Projects\tmp\2\FsUnit-master\src\FsUnit.Xunit\CustomMatchers.fs:line 121
   at NHamcrest.CustomMatcher`1.Matches(T item) in C:\Documents and Settings\Graham\My Documents\NHamcrest\NHamcrest\CustomMatcher.cs:line 28

   at <StartupCode$FsUnit-MbUnit-Test>.$HaveLengthTests.Seq with 1 item should fail to have Length [email protected](Unit unitVar0) in D:\My\Projects\tmp\2\FsUnit-master\tests\FsUnit.MbUnit.Test\haveLengthTests.fs:line 45
   at [email protected](Object arg) in D:\My\Projects\tmp\2\FsUnit-master\src\FsUnit.Xunit\CustomMatchers.fs:line 29
   at NHamcrest.CustomMatcher`1.Matches(T item) in C:\Documents and Settings\Graham\My Documents\NHamcrest\NHamcrest\CustomMatcher.cs:line 28
   at FsUnit.Test.haveLength tests.Seq with 1 item should fail to have Length 1() in D:\My\Projects\tmp\2\FsUnit-master\tests\FsUnit.MbUnit.Test\haveLengthTests.fs:line 45

Expected System.ArgumentException

Expected : System.ArgumentException
But      : was <StartupCode$FsUnit-MbUnit-Test>.$HaveLengthTests+Seq with 1 item should fail to have Length 1@45

   at FsUnit.Test.haveLength tests.Seq with 1 item should fail to have Length 1() in D:\My\Projects\tmp\2\FsUnit-master\tests\FsUnit.MbUnit.Test\haveLengthTests.fs:line 45

shouldFail tests 
Passed0Failed1Inconclusive or Skipped0
Duration: 0.011s, Assertions: 2.
shouldFaild should throw an exception 

Duration: 0.008s, Assertions: 2.
Expected True
Method should fail

Expected : True
But      : was False

   at <StartupCode$FsUnit-MbUnit-Test>.$ShouldFailTests.shouldFaild should throw an [email protected](Unit unitVar0) in D:\My\Projects\tmp\2\FsUnit-master\tests\FsUnit.MbUnit.Test\shouldFailTests.fs:line 23
   at [email protected](Object arg) in D:\My\Projects\tmp\2\FsUnit-master\src\FsUnit.Xunit\CustomMatchers.fs:line 29
   at NHamcrest.CustomMatcher`1.Matches(T item) in C:\Documents and Settings\Graham\My Documents\NHamcrest\NHamcrest\CustomMatcher.cs:line 28
   at FsUnit.Test.shouldFail tests.shouldFaild should throw an exception() in D:\My\Projects\tmp\2\FsUnit-master\tests\FsUnit.MbUnit.Test\shouldFailTests.fs:line 23

Expected System.Exception

Expected : System.Exception
But      : was <StartupCode$FsUnit-MbUnit-Test>.$ShouldFailTests+shouldFaild should throw an exception@23

   at FsUnit.Test.shouldFail tests.shouldFaild should throw an exception() in D:\My\Projects\tmp\2\FsUnit-master\tests\FsUnit.MbUnit.Test\shouldFailTests.fs:line 23

I expected

"This string is long" |> should contain "string"

to do something like a test framework's Assert.Contains<string,string>, and the error message I get was (at first) quite confusing:

Test Name:  Test contain raw
Test Outcome:   Failed
Test Duration:  0:00:00.081

Result Message: 
Exception of type 'FsUnit.Xunit+MatchException' was thrown.
Position: First difference is at position 0
Expected: Contains string
Actual:   was This string is long
Result StackTrace:  
at FsUnit.Xunit.Assert.That.Static[a](a actual, IMatcher`1 matcher)
  at TestTestFramework.Test contain raw() in <snip>TestTestFramework.fs:line 13

Currently there are separate assemblies in the FsUnit 1.3.0.1 NuGet package:

• lib/net20: built against .Net 2.0, references FSharp.Core 2.3.0.0
• lib/net40: built against .Net 2.0, references FSharp.Core 2.3.0.0

Would it be possible to keep the net20 as is but change the net40 one to build against .Net 4.0 and reference FSharp.Core 4.3.0.0?

I have a binding redirect issue in one of my projects where I need to redirect to FSharp.Core 2.3.0.0 for .Net 3.5 and to FSharp.Core 4.3.1.0 for all other platforms, but this does not work with FsUnit as it will always try to load the 2.3.0.0 one even in .Net 4.0 - which then conflicts with the other dependencies or fails to load entirely. In other words, since both reference exactly the same version, I cannot treat them separately for .Net 2.0 and .Net 4.0.

In using fsunit from a strongly-named assembly I get the folllowing error

1) Test Error : TryFsunit.lib1.hello System.IO.FileLoadException : Could not load file or assembly 'FsUnit.NUnit, Version=1.3.1.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. A strongly-named assembly is required. (Exception from HR ESULT: 0x80131044) at TryFsunit.lib1.hello()

Nunit works fine. It's just FSunit that isn't signed. There are many ways to sign an assembly in the FSUnit build process -- see msdn article

To reproduce

1. create a small library project. See (1)
2. add fsunit from nuget to the project
3. add any test
4. sign that library with a strong name. (There are many ways to do that. I used the <OtherFlags>--keyfile:SomeSignature.snk</OtherFlags> method in the .fsproj). See (2)
5. build with msbuild
6. run from command line "nunit-console.exe"
7. you will see the above error "Could not load file or assembly 'FsUnit.NUnit'...A strongly-named assembly is required."

(1) Sample library1.fs fragment

let add a b = a + b
// this fails at test runtime
[<Test>] 
let hello2() = add 2 3 |> should equal 5
// This works, which means: nunit is strong signed. But fsunit is not. 
[<Test>] 
let hello() =
    let n = add 2 3
    Assert.That(n,Is.EqualTo(5))

(2) Sample .fsproj file fragment with <OtherFlags>

<PropertyGroup>
    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
    <OutputType>Library</OutputType>
  ....
  <OtherFlags>--keyfile:SignKeyLifeQuest.snk</OtherFlags>
</PropertyGroup>

It seems there is no FsUnit.Xunit netstandard support yet although the main package already got it in march. Would be nice to see this for the other packages as well

Thank you for the wonderful FsUnit.

I was hoping to use FsUnit and FsCheck together in joyous union of ultimate-test-nirvana-fun, but alas, they 💕 different versions of xUnit. FsUnit desiring exactly xunit (= 1.9.1) and FsCheck a little more open to xunit (≥ 1.9.2 && < 3.0).

How can I help make these fine libraries play together?

The first assertion does what you would expect, but the second (array version) is considered a match failure. Using dmohl-FsUnit-dee815d.

open Xunit
open FsUnit.Xunit

[1] |> should equal [1]
// FAILS
[|1|] |> should equal [|1|]