Top 20 NuGet aaa Packages

NSubstitute is a friendly substitute for .NET mocking frameworks. It has a simple, succinct syntax to help developers write clearer tests. NSubstitute is designed for Arrange-Act-Assert (AAA) testing and with Test Driven Development (TDD) in mind.
Shouldly - Assertion framework for .NET. The way asserting *Should* be
The most powerful free mocking library available for .NET developers.
Auto-mocking Autofac container that uses NSubstitute.
NMock3 is a Mocking framework that uses lambda syntax to setup expectations and test interactions between classes and interfaces.
Automatic generation of C# code for Shouldly unit tests. Reads your test output and generates a matching test for each property in your model. An easy way to achieve 100% test coverage.
Automatic generation of C# object literal initialiser, based on runtime data. Reads the object at runtime and writes the equivalent C# to recreate that object in code. Useful for snapshotting the output of one unit test for input to the next.
Testify is a unit test assertions, test data creation and contract verification framework. It's not dependent on any specific unit testing framework.
Testify is a unit test assertions, test data creation and contract verification framework. It's not dependent on any specific unit testing framework. Testify.Moq adds mocking support via Moq.
The library for writing tests in BDD and AAA styles