ServiceProviderValidationExtensions

This library makes more fine-grained control possible for registrations in ServiceProvider. These are especially useful for large complicated application.

It contains the following features:

Exclusive service registration

A service can be registered as exclusive, meaning that not more than once occourence of it can exists in the ServiceProvider. To register a service as exclusive, call SetExclusiveService on the IServiceCollection:

serviceCollection.SetExclusiveService<IMyService>()

Alternatively, overloads for the more common signatures of AddSingleton, AddScoped and AddTransient exists, e.g.:

serviceCollection.AddSingleton<MyService>(ServiceValidation.ExclusiveService);
serviceCollection.AddSingleton<IMyService, MyService>(ServiceValidation.ExclusiveService);

Exclusive implementation registration

An implementation can be registered as exclusive, meaning that not more than once occourence of the combination of the type of service and the implementation can exists in the ServiceProvider. To register a service as exclusive, call SetExclusiveImplementation on the IServiceCollection:

serviceCollection.SetExclusiveImplementation<IMyService, MyService>()

Alternatively, overloads for the more common signatures of AddSingleton, AddScoped and AddTransient exists, e.g.:

serviceCollection.AddSingleton<IMyService, MyService>(ServiceValidation.ExclusiveService);

Reporting

The reporting functionality makes it possible to get insights into the registrations in the ServiceProvider. It currently supports detecting duplicate service registrations.

void ConfigureReporting(ReportConfigurer rb)
{
    rb.OnDuplicateService(
        ds => Console.WriteLine($"{ds.ServiceType} is registered {dsc.ImplementationTypes.Count} times"),
        c => c.Except(typeof(IConfigureOptions<>)).Except<ILoggerProvider>());
}

Host.CreateDefaultBuilder().UseServiceProviderExtendedValidation(ConfigureReporting).Build();

Invoking the validation

There are two ways of invoking the validation, as described below. In case any validation fails, a ServiceProviderValidationException is thrown.

Hosting extensions

Reference the ServiceProviderValidationExtensions.Hosting package and use the UseServiceProviderExtendedValidation extension method.

Host.CreateDefaultBuilder()
    .UseServiceProviderExtendedValidation()

or

Host.CreateApplicationBuilder()
    .ConfigureContainerWithServiceProviderExtendedValidation()

Manually building the ServiceProvider

Call BuildServiceProviderWithValidation on the IServiceCollection, e.g.

serviceCollection.BuildServiceProviderWithValidation()