Kuna.Extensions.DependencyInjection.Validation

Effortless testing of dependency registrations with Microsoft.Extensions.DependencyInjection

Installation

Install the Nuget Package

Package Manager Console

Install-Package Kuna.Extensions.DependencyInjection.Validation

.NET Core CLI

dotnet add package Kuna.Extensions.DependencyInjection.Validation

Usage

This library allows you to scan assemblies and verify that all dependencies required for the instantiation of types are registered with the dependency injection container. It has been tested exclusively with the base container implementation provided by Microsoft.

To utilize the library, you may add a test to your API project using the structure provided in the example.

First, create an instance of the generic RegistrationValidator, where the generic type parameter is the entry point for your application (e.g. Program). Then, call the Validate method and provide the types to be tested. The RegistrationValidator will scan the assemblies for definitions of the specified types, including concrete types and open generic interface definitions. For example, if you are using MediatR to dispatch commands or events, you may specify open generic interfaces such as IRequest<> or INotificationHandler<>.

The WebApplicationFactory is used to initiate the bootstrapping process for the application, which configures the ServiceCollection. To prevent the app from running, it is necessary to handle two exceptions: FailureException and SuccessException. When the SuccessException is thrown, it can be safely ignored, and optional feedback can be provided by calling Result.ToString() and writing it to the output console. In the event of a FailureException, the test will fail when you call Assert.Failure (which works for both XUnit and NUnit). You can then call Result.ToString() to display the failures. If you desire a different output format, you may create an extension for the Result type.

Example

public class ServicesConfigurationTest
{
    private readonly ITestOutputHelper console;

    public ServicesConfigurationTest(ITestOutputHelper console)
    {
        this.console = console;
    }

    [Fact]
    public void VerifyDependencyRegistrations()
    {
        var assemblies = new[]
        {
            typeof(ShoppingCartsController).Assembly, // api
            typeof(IShoppingCartRepository).Assembly, // application
        };

        var verifier = new RegistrationValidator<Program>(assemblies);

        try
        {
            verifier.Validate(
                typeof(Controller),
                typeof(IHandleCommand<>));
        }
        catch (FailureException fe)
        {
            this.console.WriteLine(fe.Result.ToString());

            Assert.Fail("Could not resolve all dependencies");
        }
        catch (SuccessException e)
        {
            this.console.WriteLine(e.Result.ToString());
        }
    }
}

Example of output

Xunit.Sdk.FailException
Assert.Fail(): Could not resolve all dependencies
   at Carts.Api.Tests.ServicesConfigurationTest.VerifyDependencyRegistrations() in C:\Github\Kuna\Kuna.EventSourcing\Sample\ECommerce\Carts\Carts.Api.Tests\ServicesConfigurationTests.cs:line 43



Number of types to verify: 6

Failure messages:
-----------------------------------------
Unable to resolve service for type 'Carts.Domain.Services.IProductPriceCalculator' while attempting to activate 'Carts.Application.CommandHandlers.AddProductHandler'.

Failed to resolve:
-----------------------------------------
Kuna.EventSourcing.Core.Commands.IHandleCommand`1[[Carts.Domain.Commands.AddProduct, Carts.Domain, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]

Resolved successfuly:
-----------------------------------------
Carts.Api.Controllers.ShoppingCartsController
Kuna.EventSourcing.Core.Commands.IHandleCommand`1[[Carts.Domain.Commands.CancelShoppingCart, Carts.Domain, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]
Kuna.EventSourcing.Core.Commands.IHandleCommand`1[[Carts.Domain.Commands.ConfirmShoppingCart, Carts.Domain, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]
Kuna.EventSourcing.Core.Commands.IHandleCommand`1[[Carts.Domain.Commands.OpenShoppingCart, Carts.Domain, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]
Kuna.EventSourcing.Core.Commands.IHandleCommand`1[[Carts.Domain.Commands.RemoveProduct, Carts.Domain, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]