Top 20 NuGet aaa Packages

NSubstitute is a friendly substitute for .NET mocking libraries. 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.
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.
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.
The library for writing tests in BDD and AAA styles