danielwertheim / Ensure.That

Guard clause project for .NET

Ensure.That

Ensure.That is a simple guard clause argument validation lib, that helps you with validation of your arguments. It IS NOT for [insert your custom exception of choice here]. It aims at having an acceptable/good enough message (a bit like, take it or leave it) for devs (in logs etc) not for application users/systems etc. So no custom exceptions, messages or I18N support.

Ensure.That - Using extension methods

Ensure.That(myString).IsNotNullOrWhiteSpace();
Ensure.That(myString, nameof(myString)).IsNotNullOrWhiteSpace();

Chainable:

Ensure
  .That(myString)
  .IsNotNullOrWhiteSpace()
  .IsGuid();

Easily extendable:

public static class StringArgExtensions
{
    public static StringParam IsNotFishy(this StringParam param)
        => param.Value != "fishy"
            ? param
            : throw Ensure.ExceptionFactory.ArgumentException("Something is fishy!", param.Name);
}

Ensure.That(myString, nameof(myString)).IsNotFishy();

NOTE: If you are worried that the constructed public readonly struct Param<T> {} created for the argument being validated will hurt your performance you can use any of the other constructs e.g. contextual Ensure.String or EnsureArg (see below for samples).

Ensure.Context - Using contextual validation

Introduced in the v7.0.0 release.

Ensure.String.IsNotNullOrWhiteSpace(myString);
Ensure.String.IsNotNullOrWhiteSpace(myString, nameof(myArg));

Easily extendable:

public static class StringArgExtensions
{
    public static string IsNotFishy(this StringArg _, string value, string paramName = null)
        => value != "fishy"
            ? value
            : throw Ensure.ExceptionFactory.ArgumentException("Something is fishy!", paramName);
}

Ensure.String.IsNotFishy(myString, nameof(myString));

EnsureArg - Using simple static methods

Introduced in the v5.0.0 release.

EnsureArg.IsNotNullOrWhiteSpace(myString);
EnsureArg.IsNotNullOrWhiteSpace(myString, nameof(myArg));

Easily extendable:

public static partial class EnsureArg
{
    public static string IsNotFishy(string value, string paramName = null)
        => value != "fishy"
            ? value
            : throw Ensure.ExceptionFactory.ArgumentException("Something is fishy!", paramName);
}

EnsureArg.IsNotFishy(myString, nameof(myString));

Samples

The Samples above just uses string validation, but there are more. E.g.:

• Strings
• Numerics
• Collections (arrays, lists, collections, dictionaries)
• Booleans
• Guids

Get up and running with the source code

Unit-tests are written using xUnit and there are no integration tests, hence you should just be able to:

• Pull
• Compile
• Run the tests

Easiest done using:

git clone ...

and

dotnet test src/