Verify VS xUnit

Bogus - For creating fake data Verify - Snapshot testing for .NET MELT - For testing ILogger usage Stryker - Mutation Testing for .NET TestContainers - run docker programmatically in integration tests

Are you familiar with "snapshot testing" tools such as Verify that store expected output in files. It's still unit testing.

We can use Verify to perform snapshot testing and check for the correct output of the program. In order to make things easier and simplify working with process output capturing and invocation, I used CliWrap.

You will have to write extra code to set up a code base to get it started (there's always a large initial cost in getting things set up, and you'll be writing code that helps get the state of your application setup), but I can assure you that our team paid the initial tax and the only reason our tests change now is because of requirements changes (and maybe sometimes because the testing tools we use like Verify have some breaking changes in behavior when we upgrade). Otherwise, it helps us identify issues in our code, particularly when we do library upgrades or change to a different library. Again, our tests do not change when we completely reimplement anything, just when the external contract changes. We just get to refactor/reimplement and have confidence that the old behavior stays the same. And then you get to hook up a benchmark to your tests and, if your reason for refactoring was performance reasons, you can show that it was effective.

I assume this means you can take something like this, combine it with Snapshot/Approval testing (link to a library I have used), and then you have some quick-to-generate tests that help guard against regressions (even visual ones) by say:

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.