Visual Studio Fix

Menu Bar -> Test -> Test Settings -> Default Processor Architecture -> X64

After upgrading my .NET Core project which targets net461 to csproj I have this issue again when trying to run dotnet test in the command line it always runs the x86 build.

I ran into the same issue today on Windows 10 x64. It seems the dotnet test runner always runs as 32 bit executable and hence expects x86 binaries. Forcing both the ASP.NET Core and the xUnit test project to build x86 assemblies works for me as a stopgap measure.

"buildOptions": { "platform": "x86" }

I did a little testing today. The problem is if you try to test an executable project/web app, referencing Microsoft.AspNetCore.Server.Kestrel (or any project that indirectly references that package, like a Microsoft.AspNetCore package for example)

Steps to reproduce:

Create ConsoleApp with this as a ConsoleApp1.csproj:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net461</TargetFramework>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Server.Kestrel" Version="1.1.2" />
  </ItemGroup>
</Project>

Test class in the console app that will be tested:

namespace ConsoleApp1
{
    public class ConsoleClass
    {
        public int Method()
        {
            return 123;
        }
    }
}

Create xUnit test project with this as .csproj:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net461</TargetFramework>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.0.0" />
    <PackageReference Include="xunit" Version="2.3.0-beta3-build3705" />
    <PackageReference Include="xunit.runner.visualstudio" Version="2.3.0-beta3-build3705" />
    <DotNetCliToolReference Include="dotnet-xunit" Version="2.3.0-beta3-build3705" />
  </ItemGroup>
  <ItemGroup>
    <ProjectReference Include="..\ConsoleApp1\ConsoleApp1.csproj" />
  </ItemGroup>  
</Project>

The test method class:

using ConsoleApp1;
using Xunit;

namespace XUnitTestProject1
{
    public class UnitTest1
    {
        [Fact]
        public void Test1()
        {
            var consoleTest = new ConsoleClass();
            var returned = consoleTest.Method();
            Assert.Equal(123, returned);
        }
    }
}

Expected behavior

running dotnet xunit causes test to pass.

Actual behavior

running dontet xunit causes the test to fail dotnet xunit output:

Detecting target frameworks in XUnitTestProject1.csproj...
Building for framework net461...
  ConsoleApp1 -> d:\michal\Documents\Visual Studio 2017\Projects\CoreXUnitNet461\ConsoleApp1\bin\Debug\net461\ConsoleApp1.exe
  XUnitTestProject1 -> d:\michal\Documents\Visual Studio 2017\Projects\CoreXUnitNet461\XUnitTestProject1\bin\Debug\net461\XUnitTestProject1.dll
Running desktop CLR tests for framework net461...
xUnit.net Console Runner (64-bit Desktop .NET 4.0.30319.42000)
  Discovering: XUnitTestProject1
  Discovered:  XUnitTestProject1
  Starting:    XUnitTestProject1
    XUnitTestProject1.UnitTest1.Test1 [FAIL]
      System.BadImageFormatException : Nie można załadować pliku lub zestawu 'ConsoleApp1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' lub jednej z jego zależności. Próbowano załadować program w niepoprawnym formacie.
      Stack Trace:
           w XUnitTestProject1.UnitTest1.Test1()
  Finished:    XUnitTestProject1
=== TEST EXECUTION SUMMARY ===
   XUnitTestProject1  Total: 1, Errors: 0, Failed: 1, Skipped: 0, Time: 0,137s

Removing the Microsoft.AspNetCore.Server.Kestrel reference from the Console App causes the test to pass Changing the project type from Console Application to Class Library, even with the Microsoft.AspNetCore.Server.Kestrel reference present, causes the test to pass Running dotnet test causes the tests to pass as well

Environment Data

dotnet info output:

.NET Command Line Tools (1.0.4)

Product Information:
 Version:            1.0.4
 Commit SHA-1 hash:  af1e6684fd

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.14393
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\1.0.4

Additional notes

Running tests in Visual Studio 2017 works properly every time, only the cli tools seem to be broken

I tried running tests with different versions of a dotnet-xunit package as well as different versions of Microsoft.AspNetCore.Server.Kestrel package. The results were always the same.

I made a simple test repo that has 5 projects, showcasing different project type/references combination:

• 3 executable projects, 1 without Kestrel reference
• 1 Class library project with Kestrel reference
• xUnit test project with 4 test methods

Running tests with dotnet xunit causes 2 out of 4 test methods to fail with System.BadImageFormatException

@RehanSaeed You are my savior 👍

@RehanSaeed THANK YOU! A thousand times THANK YOU ! The Visual Studio setting you pointed out fixed got things working here!

Thanks but anyway - it should be fixed.