SetSharp

Tired of manually mapping appsettings.json to C# classes? SetSharp is a powerful .NET source generator that automatically creates strongly-typed C# configuration classes directly from your JSON settings, seamlessly integrating with the IOptions pattern.

Say goodbye to magic strings and runtime errors. With SetSharp, your configuration becomes a first-class citizen in your codebase, complete with compile-time safety and IntelliSense support.

Key Features

• Automatic POCO Generation: Mirrors your appsettings.json structure into clean, ready-to-use C# records.
• Strongly-Typed Access: No more _configuration["Section:Key"]. Access settings with options.Value.Section.Key.
• Seamless DI Integration: Automatically generates extension methods to register your configuration with Dependency Injection using the IOptions pattern.
• Zero Runtime Overhead: All code generation happens at compile time, adding no performance cost to your application.
• Configurable Generation: Easily enable or disable IOptions pattern integration to fit your project's needs.

Prerequisites

SetSharp has the following dependencies that you need to be aware of:

• Microsoft.Extensions.Configuration.Abstractions This is a fundamental dependency and is always required for the generator to function. If this package is missing, you will receive a compile-time error (SSG003).

• Microsoft.Extensions.Options.ConfigurationExtensions This package is required only if you are using the automatic IOptions pattern generation (which is enabled by default). If this package is missing while the feature is active, you will receive a compile-time error (SSG002).

You can disable the IOptions pattern feature and remove this second dependency by setting the SetSharp_OptionPatternGenerationEnabled MSBuild property to false in your .csproj file. See the Configuration section for details.

Getting Started

Follow these steps to integrate SetSharp into your .NET project.

1. Install the NuGet Package

Add the SetSharp NuGet package to your project using the .NET CLI or the NuGet Package Manager.

dotnet add package SetSharp

2. Add appsettings.json to your Project File

For the source generator to work its magic, you must explicitly tell the compiler to include your appsettings.json file during the build process. Edit your .csproj file and add the following ItemGroup:

<ItemGroup>
  <AdditionalFiles Include="appsettings.json" />
</ItemGroup>

3. Build Your Project

That's it! Simply build your project. SetSharp will run automatically, generating your configuration records in the background.

dotnet build

How to Use

SetSharp generates two key things for you: strongly-typed records and Dependency Injection extension methods.

1. Generated Configuration Records

For an appsettings.json like this:

{
  "ConnectionStrings": {
    "DefaultConnection": "Server=.;Database=MyDb;Trusted_Connection=True;"
  },
  "FeatureManagement": {
    "EnableNewDashboard": true
  }
}

SetSharp will generate corresponding C# records, within the SetSharp.Configuration namespace:

namespace SetSharp.Configuration
{
    public partial record RootOptions
    {
        public ConnectionStringsOptions ConnectionStrings { get; init; }
        public FeatureManagementOptions FeatureManagement { get; init; }
    }

    public partial record ConnectionStringsOptions
    {
        public const string SectionName = "ConnectionStrings";
        public string DefaultConnection { get; init; }
    }

    public partial record FeatureManagementOptions
    {
        public const string SectionName = "FeatureManagement";
        public bool EnableNewDashboard { get; init; }
    }
}

2. Dependency Injection with the Options Pattern

SetSharp makes registering these records with your DI container incredibly simple by generating extension methods for IServiceCollection.

You have two ways to register your settings:

A) Register a specific option:

Use the generated Add[OptionName] method to register a single configuration section.

// In your Program.cs or Startup.cs
builder.Services.AddConnectionStringsOptions(builder.Configuration);

B) Register all options at once:

Use the convenient AddAllGeneratedOptions method to register all settings from your appsettings.json in a single call.

// In your Program.cs or Startup.cs
builder.Services.AddAllGeneratedOptions(builder.Configuration);

Once registered, you can inject your settings anywhere in your application using the standard IOptions<T> interface.

public class MyService
{
    private readonly ConnectionStringsOptions _connectionStrings;

    public MyService(IOptions<ConnectionStringsOptions> connectionStringsOptions)
    {
        _connectionStrings = connectionStringsOptions.Value;
    }

    public void DoWork()
    {
        var connectionString = _connectionStrings.DefaultConnection;
        // ... use the connection string
    }
}

Configuration (via MSBuild Properties)

You can control the behavior of SetSharp by setting MSBuild properties in your project's .csproj file.

<PropertyGroup>
  <SetSharp_OptionPatternGenerationEnabled>false</SetSharp_OptionPatternGenerationEnabled>
  <SetSharp_SourceFile>config/production.json</SetSharp_SourceFile>
</PropertyGroup>

SetSharp_OptionPatternGenerationEnabled

Controls whether the Dependency Injection extension methods for the IOptions pattern are generated.

• true (Default): Generates Add[OptionName] and AddAllGeneratedOptions extension methods. Requires a reference to Microsoft.Extensions.Options.ConfigurationExtensions.
• false: Skips generation of DI extension methods. This removes the dependency on Microsoft.Extensions.Options.ConfigurationExtensions.

SetSharp_SourceFile

Specifies the name of the JSON configuration file to use as the source for generation. If you use this, remember to update the <AdditionalFiles> item in your .csproj to match the new name.

• Default: appsettings.json

If this property is set but the file cannot be found in the project's AdditionalFiles, you will receive a compile-time error (SSG004).

Future Plans

SetSharp is actively being developed. Have an idea or a feature request? Feel free to open an issue on GitHub to discuss it!

Changelog

See CHANGELOG.md for version history.

Contributing

Contributions are welcome! Whether it's a new feature idea, a bug report, or a pull request, your input is valued. Please feel free to open an issue to discuss your ideas or submit a pull request with your improvements.

License

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