xUnit VS runtimelab

Several well-known NuGet packages such as xUnit.net, FluentAssertions, StyleCop, Entity Framework Core, and others include by default a significant number of Roslyn analyzers. They help you adhere to the conventions and best practices of these libraries.

Most of my rules apply to document types, so let's build some tests for document types. We start by creating a new test class and a new test function and getting a list of all document types. This test is created using xUnit and FluentAssertions:

xUnit -> https://xunit.net/

.NET / xUnit / NUnit / MSTest

This library extends the traditional assertions provided by frameworks like MSTest, NUnit, or XUnit by offering a more extensive set of extension methods. Fluent Assertions supports a wide range of types like collections, strings, and objects and even allows for more advanced assertions like throwing exceptions.

You can verify the functionality of this validator by writing the following tests (using xUnit):

The git repo has other runners. AssemblyRunner appears to be the best fit for an already compiled tests project, but there is a runner that can be wrapped into an MSBuild task for example.

At this point you're going to see a familiar screen asking you to select a project. Here we're looking for a test project. By default, Visual Studio gives you access to 3 different testing frameworks based on your choice of project. These are MSTest, XUnit and NUnit. Ultimately, all 3 of these testing accomplish the same thing, and I've worked with all of them at various points in my career. The difference is mainly in exact syntax and documentation. Although, it's generally considered that MSTest is a little "older" than NUnit or XUnit, so I tend to see it less now. For the purposes of this demo, I'm going to go with NUnit:

xUnit unit tests tool

Use a testing framework: Utilize a testing framework like NUnit, xUnit, or MSTest to create, organize, and run your tests. These frameworks provide a consistent way to write tests, generate test reports, and integrate with continuous integration tools.

There was a "green thread" experiment for dotnet a while ago, here is the conclusion: https://github.com/dotnet/runtimelab/issues/2398

Experiment result write-up: https://github.com/dotnet/runtimelab/blob/e69dda51c7d796b812...

TLDR: The green threads experiment was a failure as it found (expected and obvious) issues that the Java applications are now getting to enjoy, joining their Go colleagues, while also requiring breaking changes. It, however, gave inspiration to subsequent re-examination of current async/await implementation and whether it can be improved by moving state machine generation and execution away from IL completely to runtime. It was a massive success as evidenced by preliminary overhead estimations in the results.

Yeah, it kind of is. There are quite a few of experiments that are conducted to see if they show promise in the prototype form and then are taken further for proper integration if they do.

Unfortunately, object stack allocation was not one of them even though DOTNET_JitObjectStackAllocation configuration knob exists today, enabling it makes zero impact as it almost never kicks in. By the end of the experiment[0], it was concluded that before investing effort in this kind of feature becomes profitable given how a lot of C# code is written, there are many other lower hanging fruits.

To contrast this, in continuation to green threads experiment, a runtime handled tasks experiment[1] which moves async state machine handling from IL emitted by Roslyn to special-cased methods and then handling purely in runtime code has been a massive success and is now being worked on to be integrated in one of the future version of .NET (hopefully 10?)

[0] https://github.com/dotnet/runtime/issues/11192

[1] https://github.com/dotnet/runtimelab/blob/feature/async2-exp...

Unlike these folks from dotnet, which tested directly on ASP for real workload

  https://github.com/dotnet/runtimelab/issues/2398?darkschemeovr=1

[1] https://github.com/dotnet/runtimelab/issues/2398

The only way to avoid it is to not build on top of Java or not adding any features on top of Java.

> To give another example with C#, there has been a lot of recent discussion about finding potential alternatives to their async-await concurrency model. They cite the level of effort it takes to maintain the async await style code and the costs that come from this.

I had a very different take-away. They did PoC with virtual threads and decided it's not worth the switch now and async-await that they have is good enough.

https://github.com/dotnet/runtimelab/issues/2398

> Some of the languages it gets compared too aren't even that old yet.

C# is old enough to drink and Scala just had its 20th birthday this week :)

It was tried and the dotnet team decided to drop it: https://github.com/dotnet/runtimelab/issues/2398

Technical details here: https://github.com/dotnet/runtimelab/blob/feature/green-thre...

Just last month .NET ended a green threading experiment, mainly because the overhead it adds to FFI was too high:

https://github.com/dotnet/runtimelab/issues/2398

Rust had green threads until late 2014, and they were removed because of their impact on performance.

Everyone has done the basic research: green threading is a convenient abstraction that comes with certain performance trade offs. It doesn't work for the kind of profile that Rust is trying to target.