DomainGuard

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📘 Detailed Explanation

DomainGuard is a lightweight, high-performance guard clause library designed specifically for:

• Domain-Driven Design (DDD)
• Clean Architecture
• Enterprise applications
• Value Objects, Aggregates, Entities, Domain Services
• High-performance APIs and microservices

Key Principles

Zero dependencies
DomainGuard does not rely on external packages such as FluentValidation. It is intentionally minimal.

Zero allocations
Only pure value checks. No memory pressure, no object creation.

Modern Generic Math API
Uses .NET INumber<T> for universal numeric validation without boxing.

Expressive Errors
Errors are automatically enriched using CallerArgumentExpression.

Fast
Pure inlineable guard clauses with no reflection, no attributes, no scanning.

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🚀 Usage

Install via NuGet

dotnet add package DomainGuard

Basic Examples

using DomainGuard;

// Null Checks
name.EnsureNonNull();
address.EnsureNull();

// Default Checks
id.EnsureNotDefault();

// Numeric Checks
quantity.EnsurePositive();
balance.EnsureNonNegative();
amount.EnsureGreaterThan(5);
price.EnsureWithinRange(0, 100);

// String Checks
email.EnsureValidEmail();
title.EnsureNonBlank();
fileUrl.EnsureImageUrl();
sku.EnsureMatchesPattern(@"^[A-Z0-9]+$");

// Collections
items.EnsureAny();
collection.EnsureNonEmpty();

// Enums
status.EnsureEnumValueDefined();

// Dictionaries
dict.EnsureKeyExists("key");

// Booleans
isValid.EnsureTrue();
isDeleted.EnsureFalse();

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Value Object Example

public sealed class ProductName
{
    public string Value { get; }

    public ProductName(string value)
    {
        Value = value
            .EnsureNonBlank()
            .EnsureLengthInRange(3, 100);
    }
}

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Aggregate Example

public void ChangePrice(decimal newPrice)
{
    newPrice.EnsurePositive();

    Price = newPrice;
}

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🧪 Unit Tests

DomainGuard includes full test coverage with:

• xUnit
• FluentAssertions
• Coverage via Coverlet + ReportGenerator

Naming style:

MethodName_WhenCondition_ShouldExpectedBehavior

Example:

EnsurePositive_WhenValueIsGreaterThanZero_ShouldReturnValue()

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🎯 Why DomainGuard?

| Feature | Benefit | |--------|---------| | Zero Dependencies | No heavy packages, minimalistic and clean | | Fast | No reflection, no boxing | | CallerArgumentExpression | Beautiful domain error messages | | Generic Math (INumber<T>) | Universal numeric rule support | | 100% tested | Confidence in production | | Designed for DDD | Perfect for Value Objects & Aggregates | | NuGet-ready | Metadata, docs, CI/CD |

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👥 Contributors

| Name | Role | |------|------| | Tural Suleymani | Author, Maintainer |

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📄 License

This project is licensed under the MIT License.
See the LICENSE file for details.

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💬 Support

• Issues: https://github.com/turalsuleymani/DomainGuard/issues
• PRs: Welcome

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⭐ If you like DomainGuard...

Please star the repo on GitHub . It helps visibility and supports future development!