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.
The library for writing tests in BDD and AAA styles
NMock3 is a Mocking framework that uses lambda syntax to setup expectations and test interactions between classes and interfaces.
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.