xUnit: add Startup to test project and reuse configurations

readme.md

xUnit: add Startup to test project and reuse configurations

Outline:

• Create a xUnit test project;
• Add the necessary NuGet packages:
  • Microsoft.AspNetCore.TestHost;
  • Microsoft.Extensions.Configuration.Json;
• Add the Startup and InjectionFixture classes above;
• Make your test classes implement IClassFixture<InjectionFixture> and receive an instance of InjectionFixture in their constructors;
• Add the optional appsettings.json configuration file if you need it.

---

References:

• https://stackoverflow.com/a/41350245/484108
• https://xunit.github.io/docs/shared-context.html#class-fixture

InjectionFixture.cs

using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.TestHost;
using System;
using System.Net.Http;

namespace Tests
{
    public class InjectionFixture : IDisposable
    {
        private readonly TestServer server;
        private readonly HttpClient client;

        public InjectionFixture()
        {
            server = new TestServer(new WebHostBuilder().UseStartup<Startup>());
            client = server.CreateClient();
        }

        public IServiceProvider ServiceProvider => server.Host.Services;

        public void Dispose()
        {
            Dispose(true);
        }

        protected virtual void Dispose(bool disposing)
        {
            if (disposing)
            {
                server.Dispose();
                client.Dispose();
            }
        }
    }
}

MyTests.cs

using Xunit;

namespace Tests
{
    public class MyTests : IClassFixture<InjectionFixture>
    {
        private readonly InjectionFixture injection;

        public MyTests(InjectionFixture injection)
        {
            this.injection = injection;
        }

        [Fact]
        public void SomeTest()
        {
            // TODO: add test code.
        }
    }
}

Startup.cs

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

namespace Tests
{
    public class Startup
    {
        public Startup(IHostingEnvironment env)
        {
            var builder = new ConfigurationBuilder()
                .SetBasePath(env.ContentRootPath)
                .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
                .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
                .AddEnvironmentVariables();

            Configuration = builder.Build();
        }

        public IConfigurationRoot Configuration { get; }

        public void ConfigureServices(IServiceCollection services)
        {
            // TODO: add your code.
        }

        public void Configure(IApplicationBuilder app)
        {
            // TODO: add your code.
        }
    }
}