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dotnet test with xUnit and full .NET framework causes System.BadImageFormatException

See original GitHub issue

Steps to reproduce

Create a web application that targets full .NET framework, e.g. with: "frameworks": { "net461": { } },

Create a class library with xUnit, testhost and web application as dependencies - e.g.:

{
  "version": "1.0.0-*",
  "testRunner": "xunit",
  "dependencies": {
    "xunit": "2.1.0",
    "dotnet-test-xunit": "1.0.0-rc2-build10015",
    "Microsoft.AspNetCore.TestHost": "1.0.0-rc2-final",
    "WebApp":  "*" 
  },
  "frameworks": {
    "net461": { }
  }
}

Create a unit test in class library that uses the web application:

public class IntegrationTests
{
    [Fact]
    public void Test()
    {
        var builder = new WebHostBuilder();
        builder.UseStartup<Startup>();
    }       
}

Expected behavior

Tests are executed properly

Actual behavior

Project WebApp (.NETFramework,Version=v4.5.1) was previously compiled. Skipping compilation.
Project WebApp.Tests (.NETFramework,Version=v4.6.1) will be compiled because inputs were modified
Compiling WebApp.Tests for .NETFramework,Version=v4.6.1

Compilation succeeded.
    0 Warning(s)
    0 Error(s)

Time elapsed 00:00:01.4138420


xUnit.net .NET CLI test runner (32-bit win81-x86)
  Discovering: WebApp.Tests
  Discovered:  WebApp.Tests
  Starting:    WebApp.Tests
      System.BadImageFormatException : Could not load file or assembly 'WebApp, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. An attempt was made to load a program with an incorrect format.
      Stack Trace:
           at WebApp.Tests.IntegrationTests.Test()
  Finished:    WebApp.Tests
=== TEST EXECUTION SUMMARY ===
   WebApp.Tests  Total: 1, Errors: 0, Failed: 1, Skipped: 0, Time: 0,193s

Environment data

dotnet --info output:

.NET Command Line Tools (1.0.0-preview1-002702)

Product Information:
 Version:     1.0.0-preview1-002702
 Commit Sha:  6cde21225e

Runtime Environment:
 OS Name:     Windows
 OS Version:  6.3.9600
 OS Platform: Windows
 RID:         win81-x64

Issue Analytics

State:
Created 7 years ago
Comments:30 (1 by maintainers)

Top GitHub Comments

51reactions

RehanSaeedcommented, Jul 4, 2016

Visual Studio Fix

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

8reactions

felschrcommented, Mar 8, 2017

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.

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