MSpec is called a "context/specification" test framework because of the "grammar" that is used in describing and coding the tests or "specs". The grammar reads roughly like this

When the system is in such a state, and a certain action occurs, it should do such-and-such or be in some end state.

You should be able to see the components of the traditional Arrange-Act-Assert model in there. To support readability and remove as much "noise" as possible, MSpec eschews the traditional attribute-on-method model of test construction. Instead it uses custom delegates that you assign anonymous methods, and asks you to name them following a certain convention.

using Machine.Specifications;
[Subject("Authentication")]
class When_authenticating_an_admin_user
{
    static SecurityService subject;
    static UserToken user_token;
    Establish context = () => 
        subject = new SecurityService();
    Because of = () =>
        user_token = subject.Authenticate("username", "password");
    It should_indicate_the_users_role = () =>
        user_token.Role.ShouldEqual(Roles.Admin);
    It should_have_a_unique_session_id = () =>
        user_token.SessionId.ShouldNotBeNull();
}

1. Create a .NET Framework or .NET Core library project.
2. Install Nuget packages as follows:

Install-Package Machine.Specifications

3. Install the test SDK and Visual Studio runner:

Install-Package Microsoft.NET.Test.SDK
Install-Package Machine.Specifications.Runner.VisualStudio

4. Optionally, install the assert and mocking libraries:

Install-Package Machine.Specifications.Should
Install-Package Machine.Fakes

For project documentation, please visit the wiki.

A PluralSight course by @kevinkuebler is available here.

Discuss with us on Discussions, or raise an issue.

Project	Build	NuGet
Machine.Specifications
Machine.Specifications.Reporting
Machine.Specifications.Runner.Console
Machine.Specifications.Runner.ReSharper
Machine.Specifications.Runner.Rider
Machine.Specifications.Runner.TDNet
Machine.Specifications.Runner.Utility
Machine.Specifications.Runner.VisualStudio
Machine.Specifications.Should
Machine.Fakes