Skip to main content

Migrating from XUnit v2 to v3–Troubleshooting

The XUnit team decided to do a major overhaul of the XUnit libraries and created completely new V3 packages. So don't expect backwards compatibility but a significant architectural shift that brings improved performance, better isolation, and modernized APIs to .NET testing. While the migration requires some work, the benefits should make it worthwhile for most projects.

In this post I’ll share some of the migration problems I encountered and how to fix them.

XUnit.Abstractions is not recognized

This is an easy one. The XUnit.Abstractions has become an internal namespace and should no longer be referenced. Just remove any

using Xunit.Abstractions

statement from you code.

No v3 version of Serilog.Sinks.XUnit

After switching to the v3 version of the Xunit packages, I noticed that the old XUnit v2 version was still used somewhere causing the following compiler error:

The type 'FactAttribute' exists in both 'xunit.core, Version=2.4.2.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c' and 'xunit.v3.core, Version=3.0.0.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c'

The root cause turned out to be the Serilog.Sinks.XUnit NuGet package which doesn’t support xUnit.v3 yet at the moment of writing this post.

I fixed it by creating my own fork and compiling a new version of this NuGet package using xUnit.v3.

Bye, bye [UseCultureAttribute]

Before xUnit v3 I had to create my own [UseCultureAttribute] to use a different culture than the default culture to run my tests. Starting from v3, we can override the culture using either a command line switch or through our xunit.runner.json configuration file:

IAsyncLifetime changes

IAsyncLifetime now inherits from IAsyncDisposable, and the disposal behavior has changed:

Remark: Also notice the use of ValueTask instead of Task

Cancellation token warning

This last one isn’t really a show stopper (unless you have Treat warnings as errors active like me) but still useful to apply.

xUnit1051: Calls to methods which accept CancellationToken should use TestContext.Current.CancellationToken to allow test cancellation to be more responsive.

Remark: I noticed that you also have the option to inject an ITestContextAccessor instance as described here: https://anthonysimmon.com/xunit-cancellationtoken-support/

More about this new TestContext class can be found here: What's New in v3?

Popular posts from this blog

Podman– Command execution failed with exit code 125

After updating WSL on one of the developer machines, Podman failed to work. When we took a look through Podman Desktop, we noticed that Podman had stopped running and returned the following error message: Error: Command execution failed with exit code 125 Here are the steps we tried to fix the issue: We started by running podman info to get some extra details on what could be wrong: >podman info OS: windows/amd64 provider: wsl version: 5.3.1 Cannot connect to Podman. Please verify your connection to the Linux system using `podman system connection list`, or try `podman machine init` and `podman machine start` to manage a new Linux VM Error: unable to connect to Podman socket: failed to connect: dial tcp 127.0.0.1:2655: connectex: No connection could be made because the target machine actively refused it. That makes sense as the podman VM was not running. Let’s check the VM: >podman machine list NAME         ...

Azure DevOps/ GitHub emoji

I’m really bad at remembering emoji’s. So here is cheat sheet with all emoji’s that can be used in tools that support the github emoji markdown markup: All credits go to rcaviers who created this list.

VS Code Planning mode

After the introduction of Plan mode in Visual Studio , it now also found its way into VS Code. Planning mode, or as I like to call it 'Hannibal mode', extends GitHub Copilot's Agent Mode capabilities to handle larger, multi-step coding tasks with a structured approach. Instead of jumping straight into code generation, Planning mode creates a detailed execution plan. If you want more details, have a look at my previous post . Putting plan mode into action VS Code takes a different approach compared to Visual Studio when using plan mode. Instead of a configuration setting that you can activate but have limited control over, planning is available as a separate chat mode/agent: I like this approach better than how Visual Studio does it as you have explicit control when plan mode is activated. Instead of immediately diving into execution, the plan agent creates a plan and asks some follow up questions: You can further edit the plan by clicking on ‘Open in Editor’: ...