func-with-arguments.md

Func with arguments

using Shouldly;
using Pure.DI;
using System.Collections.Immutable;

DI.Setup(nameof(Composition))
    .Bind().As(Lifetime.Singleton).To<Clock>()
    .Bind().To<Dependency>()
    .Bind().To<Service>()

    // Composition root
    .Root<IService>("Root");

var composition = new Composition();
var service = composition.Root;
service.Dependencies.Length.ShouldBe(3);

service.Dependencies[0].Name.ShouldBe("Abc");
service.Dependencies[0].Id.ShouldBe(0);

service.Dependencies[1].Name.ShouldBe("Xyz");
service.Dependencies[1].Id.ShouldBe(1);

service.Dependencies[2].Id.ShouldBe(2);
service.Dependencies[2].Name.ShouldBe("");

interface IClock
{
    DateTimeOffset Now { get; }
}

class Clock : IClock
{
    public DateTimeOffset Now => DateTimeOffset.Now;
}

interface IDependency
{
    string Name { get; }
    int Id { get; }
}

class Dependency(string name, IClock clock, int id)
    : IDependency
{
    public string Name => name;
    public int Id => id;
}

interface IService
{
    ImmutableArray<IDependency> Dependencies { get; }
}

class Service(Func<int, string, IDependency> dependencyFactory): IService
{
    public ImmutableArray<IDependency> Dependencies { get; } =
    [
        dependencyFactory(0, "Abc"),
        dependencyFactory(1, "Xyz"),
        dependencyFactory(2, "")
    ];
}

Running this code sample locally

• Make sure you have the .NET SDK 9.0 or later is installed

dotnet --list-sdk

• Create a net9.0 (or later) console application

dotnet new console -n Sample

• Add references to NuGet packages
  • Pure.DI
  • Shouldly

dotnet add package Pure.DI
dotnet add package Shouldly

• Copy the example code into the Program.cs file

You are ready to run the example 🚀

dotnet run

The following partial class will be generated:

partial class Composition
{
  private readonly Composition _root;
  private readonly Lock _lock;

  private Clock? _singletonClock51;

  [OrdinalAttribute(256)]
  public Composition()
  {
    _root = this;
    _lock = new Lock();
  }

  internal Composition(Composition parentScope)
  {
    _root = (parentScope ?? throw new ArgumentNullException(nameof(parentScope)))._root;
    _lock = _root._lock;
  }

  public IService Root
  {
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    get
    {
      int overInt320;
      string overString2;
      Func<int, string, IDependency> perBlockFunc1;
      var localLockObject104 = new Object();
      Func<int, string, IDependency> localFactory105 = new Func<int, string, IDependency>((int localArg120, string localArg227) =>
      {
        lock (localLockObject104)
        {
          overInt320 = localArg120;
          overString2 = localArg227;
          if (_root._singletonClock51 is null)
          {
            using (_lock.EnterScope())
            {
              if (_root._singletonClock51 is null)
              {
                _root._singletonClock51 = new Clock();
              }
            }
          }

          IDependency localValue106 = new Dependency(overString2, _root._singletonClock51, overInt320);
          return localValue106;
        }
      });
      perBlockFunc1 = localFactory105;
      return new Service(perBlockFunc1);
    }
  }
}

Class diagram:

Loading

---
 config:
  class:
   hideEmptyMembersBox: true
---
classDiagram
	Dependency --|> IDependency
	Service --|> IService
	Composition ..> Service : IService Root
	Dependency o-- "Singleton" Clock : IClock
	Dependency *--  Int32 : Int32
	Dependency *--  String : String
	Service o-- "PerBlock" FuncᐸInt32ˏStringˏIDependencyᐳ : FuncᐸInt32ˏStringˏIDependencyᐳ
	FuncᐸInt32ˏStringˏIDependencyᐳ *--  Dependency : IDependency
	namespace Pure.DI.UsageTests.BCL.FuncWithArgumentsScenario {
		class Clock {
		}
		class Composition {
		<<partial>>
		+IService Root
		}
		class Dependency {
			+Dependency(String name, IClock clock, Int32 id)
		}
		class IDependency {
			<<interface>>
		}
		class IService {
			<<interface>>
		}
		class Service {
			+Service(FuncᐸInt32ˏStringˏIDependencyᐳ dependencyFactory)
		}
	}
	namespace System {
		class FuncᐸInt32ˏStringˏIDependencyᐳ {
				<<delegate>>
		}
		class Int32 {
			<<struct>>
		}
		class String {
		}
	}