The .NET ecosystem is vast, with countless libraries designed to make development easier, faster, and more efficient. While popular ones like Newtonsoft.Json or Entity Framework are well-known, there are several underrated libraries that can significantly enhance your projects. In this post, I’ll highlight some of these hidden gems that you might not have heard of but are definitely worth exploring.

1. SmartFormat

SmartFormat is a powerful and lightweight library for formatting strings in a much cleaner way than traditional string interpolation or concatenation. It’s particularly useful when dealing with complex formatting scenarios, such as conditional formatting, list handling, and nested structures.

Why It’s Awesome:

• Supports advanced formatting like pluralization and conditional formatting.
• Works seamlessly with localization, making it perfect for international applications.

Usage Example:

using SmartFormat;

string formatted = Smart.Format("Hello {0}, today is {1:dddd}.", "Marmik", DateTime.Now);
Console.WriteLine(formatted);

2. FluentValidation

FluentValidation is a library for building strongly-typed validation rules for your .NET objects. It allows you to keep your validation logic separate from your models, making your code more readable and maintainable.

Why It’s Awesome:

• Provides a fluent interface to define validation rules.
• Easily integrates with ASP.NET Core for request validation.

Usage Example:

using FluentValidation;

public class UserValidator : AbstractValidator<User>
{
    public UserValidator()
    {
        RuleFor(user => user.Name).NotEmpty();
        RuleFor(user => user.Email).EmailAddress();
    }
}

3. Polly

Polly is a resilience and transient fault-handling library that allows you to easily add retry, circuit breaker, timeout, and other fault-handling policies to your applications.

Why It’s Awesome:

• Helps handle transient errors gracefully, especially in distributed systems.
• Provides out-of-the-box policies that are highly customizable.

Usage Example:

using Polly;
using System.Net.Http;

var retryPolicy = Policy
    .Handle<HttpRequestException>()
    .Retry(3);

retryPolicy.Execute(() => {
    // Your HTTP call here
});

4. Humanizer

Humanizer is a small but powerful library that helps make your application’s text more readable by humanizing dates, times, numbers, and more. It’s perfect for making output user-friendly.

Why It’s Awesome:

• Converts C# enums to human-readable strings.
• Humanizes time spans, like converting "1 day ago" from DateTime.

Usage Example:

using Humanizer;

TimeSpan timeSpan = TimeSpan.FromDays(1);
Console.WriteLine(timeSpan.Humanize()); // Output: "one day"

5. Scrutor

Scrutor provides assembly scanning and registration for the .NET Core DI container. It allows you to register your services easily without manually adding every single class, making your dependency injection setup much cleaner.

Why It’s Awesome:

• Automates the registration process, reducing boilerplate code.
• Provides flexible filtering and lifetime options.

Usage Example:

services.Scan(scan => scan
    .FromAssemblyOf<SomeType>()
    .AddClasses()
    .AsImplementedInterfaces()
    .WithScopedLifetime());

6. Mapster

Mapster is a fast, flexible, and lightweight object-to-object mapper that can replace AutoMapper. It’s highly performant and requires minimal configuration compared to other mappers.

Why It’s Awesome:

• No need for extensive profiles or configurations.
• Offers powerful customization features with minimal setup.

Usage Example:

using Mapster;

var dto = source.Adapt<DestinationType>();

Conclusion

Exploring lesser-known libraries can greatly enhance your development workflow, providing new ways to tackle common challenges. These hidden gems offer powerful functionality with minimal overhead, making them valuable additions to any .NET developer’s toolkit.

Have a favorite hidden .NET library? Share it in the comments, and let’s spread the word about these underappreciated tools!