Type registration uses TryAdd and TryAddEnumerable

src/Microsoft.Health.Extensions.DependencyInjection.UnitTests/TypeRegistrationTests.cs

@@ -377,6 +377,54 @@ public void GivenADelegateFromTypeBuilder_WhenResolvingComponent_ThenResolverRet
  IComponent instance = componentFactory.Invoke();
 
  Assert.IsType<ComponentB>(instance);
+
+ Assert.Equal(2, provider.GetServices<IComponent>().Count());
+ }
+
+ [Fact]
+ public void GivenATypeBuilder_WhenRegisteringMultipleTimes_ThenNoDuplicatesAreAdded()
+ {
+ _collection.Add<ComponentA>()
+ .Transient()
+ .AsSelf()
+ .AsService<IComponent>();
+
+ _collection.Add<ComponentA>()
+ .Transient()
+ .AsSelf()
+ .AsService<IComponent>();
+
+ var provider = _collection.BuildServiceProvider();
+ var services = provider.GetServices<IComponent>();
+ Assert.Single(services);
+ }
+
+ [Fact]
+ public void GivenATypeBuilder_WhenRegisteringMultipleTimes_ThenErrorWithDifferentScopes()
+ {
+ _collection.Add<ComponentA>()
+ .Transient()
+ .AsSelf()
+ .AsService<IComponent>();
+
+ _collection.Add<ComponentA>()
+ .Singleton()
+ .AsSelf()
+ .AsService<IComponent>();
+
+ _collection.BuildServiceProvider();
+
+ Assert.Collection(_collection, r =>
+ {
+ Assert.Equal(ServiceLifetime.Transient, r.Lifetime);
+ Assert.Equal(typeof(ComponentA), r.ServiceType);
+ Assert.Equal(typeof(ComponentA), r.ImplementationType);
+ }, r =>
+ {
+ Assert.Equal(ServiceLifetime.Transient, r.Lifetime);
+ Assert.Equal(typeof(IComponent), r.ServiceType);
+ Assert.Equal(typeof(ComponentA), r.ImplementationType);
+ });
  }
 
  [Fact]

src/Microsoft.Health.Extensions.DependencyInjection/TypeRegistrationBuilder.cs

@@ -212,14 +212,7 @@ private void RegisterType(Type serviceType, bool replace = false)
 
  serviceDescriptor = serviceDescriptor.WithMetadata(_type);
 
- if (replace)
- {
- _serviceCollection.Replace(serviceDescriptor);
- }
- else
- {
- _serviceCollection.Add(serviceDescriptor);
- }
+ AddToServiceCollection(serviceDescriptor, replace);
  }
 
  private void SetupRootRegistration(Type serviceType, bool replace)
@@ -255,16 +248,28 @@ private void SetupRootRegistration(Type serviceType, bool replace)
  {
  serviceDescriptor = serviceDescriptor.WithMetadata(_type);
 
- if (replace)
- {
- _serviceCollection.Replace(serviceDescriptor);
- }
- else
- {
- _serviceCollection.Add(serviceDescriptor);
- }
+ AddToServiceCollection(serviceDescriptor, replace);
  }
 
  _cachedResolver = provider => provider.GetService(_firstRegisteredType);
  }
+
+ private void AddToServiceCollection(ServiceDescriptor serviceDescriptor, bool replace)
+ {
+ if (replace)
+ {
+ _serviceCollection.RemoveAll(serviceDescriptor.ServiceType);
+ }
+
+ if (serviceDescriptor.ServiceType == serviceDescriptor.ImplementationType || serviceDescriptor.ImplementationFactory != null)
+ {
+ // Concrete type registration
+ _serviceCollection.TryAdd(serviceDescriptor);
+ }
+ else
+ {
+ // Register services as enumerable
+ _serviceCollection.TryAddEnumerable(serviceDescriptor);
+ }
+ }
 }