Shouldly

Shouldly is a .NET library that provides a set of extension methods for writing expressive and readable assertions in unit tests, it's designed to be an alternative to traditional assertion libraries. In the context of ASP.NET, Shouldly can be used in conjunction with test frameworks such as MSTest, xUnit, and NUnit to write more expressive and readable unit tests for the application. It provides advanced features such as support for collection-specific assertions, support for asynchronous code, and support for custom types, also includes options to customize the error message.