Source Generator to create an Interface from a class definition
Get Started
$ dotnet add package AutomaticInterfaceReadme
Automatic Interface
A C# Source Generator to automatically create Interface from classes.
What does it do?
Not all .NET Interfaces are created equal. Some Interfaces are lovingly handcrafted, e.g. the public interface of your .NET package which is used by your customers. Other interfaces are far from lovingly crafted, they are birthed because you need an interface for testing or for the DI container. They are often implemented only once or twice: The class itself and a mock for testing. They are noise at best and often create lots of friction. Adding a new method / field? You have to edit the interface, too!. Change parameters? Edit the interface. Add documentation? Hopefully you add it to the interface, too!
This Source Generator aims to eliminate this cost by generating an interface from the class, without you needing to do anything. This interface will be generated on each subsequent build, eliminating the the friction.
Example
using AutomaticInterfaceAttribute;
using System;
namespace AutomaticInterfaceExample
{
/// <summary>
/// Class Documentation will be copied
/// </summary>
[GenerateAutomaticInterface] // you need to create an Attribute with exactly this name in your solution. You cannot reference Code from the Analyzer.
class DemoClass: IDemoClass // You Interface will get the Name I+classname, here IDemoclass.
// Generics, including constraints are allowed, too. E.g. MyClass<T> where T: class
{
/// <summary>
/// Property Documentation will be copied
/// </summary>
public string Hello { get; set; } // included, get and set are copied to the interface when public
public string OnlyGet { get; } // included, get and set are copied to the interface when public
/// <summary>
/// Method Documentation will be copied
/// </summary>
public string AMethod(string x, string y) // included
{
return BMethod(x,y);
}
private string BMethod(string x, string y) // ignored because not public
{
return x + y;
}
public string CMethod<T, T1, T2, T3, T4>(string? x, string y) // included
where T : class
where T1 : struct
where T3 : DemoClass
where T4 : IDemoClass
{
return "Ok";
}
public static string StaticProperty => "abc"; // static property, ignored
public static string StaticMethod() // static method, ignored
{
return "static" + DateTime.Now;
}
/// <summary>
/// event Documentation will be copied
/// </summary>
public event EventHandler ShapeChanged; // included
private event EventHandler ShapeChanged2; // ignored because not public
private readonly int[] arr = new int[100];
public int this[int index] // currently ignored
{
get => arr[index];
set => arr[index] = value;
}
}
}
