DependencyModules.SourceGenerator by Ian Johnson
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Name: DependencyModules.SourceGenerator
Package Description
Author: Ian Johnson
NuGet: https://www.nuget.org/packages/DependencyModules.SourceGenerator/
https://www.nuget.org/packages/DependencyModules.Runtime/
You can find more details at https://github.com/ipjohnson/DependencyModules
Original Readme
DependencyModules
DependencyModules is a C# source generator package that uses attributes to create dependency injection registration modules. These modules can then be used to populate an IServiceCollection instance.
Installation
dotnet add package DependencyModules.Runtime
dotnet add package DependencyModules.SourceGenerator
Service Attributes
[DependencyModule]
- used to attribute class that will become dependency module (must be partial)[SingletonService]
- registers service asAddSingleton
[ScopedService]
- registers service asAdddScoped
[TransientService]
- registers service asAddTransient
// Registration example
[DependencyModule]
public partial class MyModule { }
// registers SomeClass implementation for ISomeService
[SingletonService]
public class SomeClass : ISomeService
{
public string SomeProp => "SomeString";
}
// registers OtherSerice implementation
[TransientService]
public class OtherService
{
public OtherService(ISomeService service)
{
SomeProp = service.SomeProp;
}
public string SomeProp { get; }
}
Container Instantiation
AddModule
- method adds modules to service collection
var serviceCollection = new ServiceCollection();
serviceCollection.AddModule<MyModule>();
var provider = serviceCollection.BuildServiceProvider();
var service = provider.GetService<OtherService>();
Module Re-use
DependencyModules creates an Attribute
class that can be used to apply sub dependencies.
// Modules can be re-used with the generated attributes
[DependencyModule]
[MyModule.Attribute]
public partial class AnotherModule { }
Parameters
Sometimes you want to provide extra registration for your module. This can be achieved by adding a constructor to your module or optional properties. Note these parameters and properties will be correspondingly implemented in the module attribute.
[DependencyModule]
public partial class SomeModule : IServiceCollectionConfiguration
{
private bool _someFlag;
public SomeModule(bool someFlag = false)
{
_someFlag = someFlag;
}
public string OptionalString { get; set; } = "";
public void ConfigureServices(IServiceCollection services)
{
if (_someFlag)
{
// custom registration
}
}
}
[DependencyModule]
[SomeModule.Attribute(true, OptionalString = "otherString")]
public partial class SomeOtherModule
{
}
Managing duplicate registration
By default a module will only be loaded once, assuming attributes are used or the modules are specified in the same AddModules
call. Seperate calls to AddModule
will result in modules being loaded multiple times. If a module uses parameters it can be useful to load a module more than once. That can be accompilished by overriding the Equals
and GetHashcode
methods to allow for multiple loads.
Services will be registered using an Add
method by default. This can be overriden using the With
property on individual service or at the DepedencyModule
level.
[SingletonService(With = RegistrationType.Try)]
public class SomeService { }
[DependencyModule(With = RegistrationType.Try)]
public partial class SomeModule { }
Realm
By default, all dependencies are registered in all modules within the same assembly. The realm allows the developer to scope down the registration within a given module.
// register only dependencies specifically marked for this realm
[DependencyModule(OnlyRealm = true)]
public partial class AnotherModule { }
[SingletonService(ServiceType = typeof(ISomeInterface),
Realm = typeof(AnotherModule))]
public class SomeDep : ISomeInterface { }
Keyed Registration
Registration attributes have a Key
property that allows for specifying the key at registration time.
[SingletonService(Key = "SomeKey")]
public class KeyService : IKeyService { }
// yields this registration line
services.AddKeyedSingleton(typeof(IKeyService), "SomeKey", typeof(KeyService));
Unit testing & Mocking
DependencyModules provides an xUnit extension to make testing much easier. It handles the population and construction of a service provider using specified modules.
> dotnet add package DependencyModules.xUnit
> dotnet add package DependencyModules.xUnit.NSubstitute
// applies module & nsubstitute support to all tests.
// test attributes can be applied at the assembly, class, and test method level
[assemlby: MyModule.Attribute]
[assembly: NSubstituteSupport]
public class OtherServiceTests
{
[ModuleTest]
public void SomeTest(OtherService test, [Mock]ISomeService service)
{
service.SomeProp.Returns("some mock value");
Assert.Equals("some mock value", test.SomeProp);
}
public void
}
Implementation
Behind the scenes the library generates registration code that can be used with any IServiceCollection
compatible DI container.
Example generated code for SutModule.cs
// SutModule.Dependencies.g.cs
public partial class SutModule
{
private static int moduleField = DependencyRegistry<SutModule>.Add(ModuleDependencies);
private static void ModuleDependencies(IServiceCollection services)
{
services.AddTransient(typeof(IDependencyOne), typeof(DependencyOne));
services.AddSingleton(typeof(IGenericInterface<>), typeof(GenericClass<>));
services.AddScoped(typeof(IScopedService), typeof(ScopedService));
services.AddSingleton(typeof(ISingletonService), typeof(SingletonService));
services.AddSingleton(typeof(IGenericInterface<string>), typeof(StringGeneric));
}
}
// SutModule.Modules.g.cs
public partial class SutModule : IDependencyModule
{
static SutModule()
{
}
// this method loads all dependencies into IServiceCollection.
public void PopulateServiceCollection(IServiceCollection services)
{
DependencyRegistry<SutModule>.LoadModules(services, this);
}
void IDependencyModule.InternalApplyServices(IServiceCollection services)
{
DependencyRegistry<SutModule>.ApplyServices(services);
}
public override bool Equals(object? obj)
{
return obj is SutModule;
}
public override int GetHashCode()
{
return HashCode.Combine(base.GetHashCode());
}
public class Attribute : System.Attribute, IDependencyModuleProvider
{
public IDependencyModule GetModule()
{
var newModule = new SutModule();
return newModule;
}
}
}
About
Generating service dependencies from attributes.
Also,by the author, a more advanced example you will find in the DemoWithTest.zip inside the zip file
How to use
Example ( source csproj, source files )
- CSharp Project
- Program.cs
- MyModule.cs
- IDatabase.cs
- Database.cs
- DatabaseCon.cs
This is the CSharp Project that references DependencyModules.SourceGenerator
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net8.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
</PropertyGroup>
<PropertyGroup>
<EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
<CompilerGeneratedFilesOutputPath>$(BaseIntermediateOutputPath)\GX</CompilerGeneratedFilesOutputPath>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="DependencyModules.Runtime" Version="1.0.0-RC9074" />
<PackageReference Include="DependencyModules.SourceGenerator" Version="1.0.0-RC9074" />
<PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="9.0.2" />
</ItemGroup>
</Project>
This is the use of DependencyModules.SourceGenerator in Program.cs
using DependencyModules.Runtime;
using InjectDemo;
using Microsoft.Extensions.DependencyInjection;
var serviceCollection = new ServiceCollection();
serviceCollection.AddModule<MyModule>();
var provider = serviceCollection.BuildServiceProvider();
var service = provider.GetService<Database>();
if(service == null)
throw new Exception("Service not found");
else
service.Open();
This is the use of DependencyModules.SourceGenerator in MyModule.cs
using DependencyModules.Runtime.Attributes;
[DependencyModule]
public partial class MyModule
{
}
This is the use of DependencyModules.SourceGenerator in IDatabase.cs
namespace InjectDemo
{
internal interface IDatabase
{
public void Open();
}
}
This is the use of DependencyModules.SourceGenerator in Database.cs
using DependencyModules.Runtime.Attributes;
namespace InjectDemo;
[SingletonService(ServiceType = typeof(Database))]
partial class Database : IDatabase
{
private readonly IDatabase con;
public Database(IDatabase con)
{
this.con = con;
}
public void Open()
{
Console.WriteLine($"open from database");
con.Open();
}
}
This is the use of DependencyModules.SourceGenerator in DatabaseCon.cs
using DependencyModules.Runtime.Attributes;
namespace InjectDemo;
[SingletonService]
public partial class DatabaseCon:IDatabase
{
public string? Connection { get; set; }
public void Open()
{
Console.WriteLine("open from database con" );
}
}
Generated Files
Those are taken from $(BaseIntermediateOutputPath)\GX
- MyModule.858.Dependencies.g.cs
- MyModule.858.Module.g.cs
using DependencyModules.Runtime.Helpers;
using InjectDemo;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
public partial class MyModule
{
private static int moduleField = DependencyRegistry<MyModule>.Add(ModuleDependencies);
private static void ModuleDependencies(IServiceCollection services)
{
services.AddSingleton(typeof(Database), typeof(Database));
services.AddSingleton(typeof(IDatabase), typeof(DatabaseCon));
}
}
using BaseAttribute = System.Attribute;
using DependencyModules.Runtime.Helpers;
using DependencyModules.Runtime.Interfaces;
using Microsoft.Extensions.DependencyInjection;
#nullable enable
public partial class MyModule : IDependencyModule
{
static MyModule()
{
}
public void PopulateServiceCollection(IServiceCollection services)
{
DependencyRegistry<MyModule>.LoadModules(services, this);
}
void IDependencyModule.InternalApplyServices(IServiceCollection services)
{
DependencyRegistry<MyModule>.ApplyServices(services);
}
public override bool Equals(object? obj)
{
return obj is MyModule;
}
public override int GetHashCode()
{
return HashCode.Combine(base.GetHashCode());
}
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Assembly | AttributeTargets.Method | AttributeTargets.Parameter, AllowMultiple = true)]
public partial class Attribute : BaseAttribute, IDependencyModuleProvider
{
public IDependencyModule GetModule()
{
var newModule = new MyModule();
return newModule;
}
}
}
#nullable disable
Usefull
Download Example (.NET C# )
Share DependencyModules.SourceGenerator
https://ignatandrei.github.io/RSCG_Examples/v2/docs/DependencyModules.SourceGenerator