Top 20 NuGet preconditions Packages

A lightweight .NET library for expressive Guard Clauses.
Code Contracts and common functionalities used by other PostSharp pattern libraries. An official PostSharp pattern library.
A simple library that facilitates runtime checks of code and allows to define preconditions and invariants within a method.
Preconditions provide convenience static methods that help to check that a method or a constructor is invoked with proper parameter or not. In other words it checks the pre-conditions.
Provides static classes for representing program contracts as preconditions in a way that's compatible with System.Diagnostics.Contracts.
Package Description
Library for easy fluent assertions
Fully managed library providing convenience methods to perform argument checks. Thrower allows to write preconditions in a pretty lean way, which reduces the clutter at the beginning of each method by removing the need to use the cumbersome 'if true then throw ex' required to validate parameters. Fo...
Preconditions provide convenience static methods that help to check that a method or a constructor is invoked with proper parameter or not. In other words it checks the pre-conditions.
Useful preconditions for Discord.Net 2.0.
SolidStack.Core.Guards is an extremely simple, unambiguous and lightweight guard clause library that allow you to write pre-conditions and post-conditions for your methods in a readable way.
Write easy fluent preconditions in methods of your code. The library is provided as it is. Use at your own risk.
Common validations.