DependencyModules.xUnit.NSubstitute 1.0.0-RC9047

DependencyModules

DependencyModules is a C# source generator package that uses attributes to create dependency injection registration modules. These packages 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 as AddSingleton
• [ScopedService] - registers service as AdddScoped
• [TransientService] - registers service as AddTransient

// 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 
{

}

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 { }

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);
  }
}