NET NET：在Xunit Test中为AppService，存储库等执行所有依赖注入

Question

我正在尝试在XUnit测试中为AppService实现依赖注入。理想的目标是运行原始应用程序启动/配置，并使用启动中的任何依赖项注入，而不是在测试中再次重新初始化所有DI，这就是整个目标。

更新：Mohsen的答案很接近。需要更新几个语法/要求错误才能起作用。

由于某种原因，原始应用程序可以工作，并且可以致电Department App Service。但是，它无法在Xunit中调用。最终使Testserver在原始应用程序中使用Startup和Configuration进行工作。现在收到以下错误：

Message: The following constructor parameters did not have matching fixture data: IDepartmentAppService departmentAppService

namespace Testing.IntegrationTests
{
    public class DepartmentAppServiceTest
    {
        public DBContext context;
        public IDepartmentAppService departmentAppService;

        public DepartmentAppServiceTest(IDepartmentAppService departmentAppService)
        {
            this.departmentAppService = departmentAppService;
        }

        [Fact]
        public async Task Get_DepartmentById_Are_Equal()
        {
            var options = new DbContextOptionsBuilder<SharedServicesContext>()
                .UseInMemoryDatabase(databaseName: "TestDatabase")
                .Options;
            context = new DBContext(options);

            TestServer _server = new TestServer(new WebHostBuilder()
                .UseContentRoot("C:\\OriginalApplication")
                .UseEnvironment("Development")
                .UseConfiguration(new ConfigurationBuilder()
                    .SetBasePath("C:\\OriginalApplication")
                    .AddJsonFile("appsettings.json")
                    .Build()).UseStartup<Startup>());

            context.Department.Add(new Department { DepartmentId = 2, DepartmentCode = "123", DepartmentName = "ABC" });
            context.SaveChanges();

            var departmentDto = await departmentAppService.GetDepartmentById(2);

            Assert.Equal("123", departmentDto.DepartmentCode);
        }
    }
}

我收到此错误：

Message: The following constructor parameters did not have matching fixture data: IDepartmentAppService departmentAppService

就像真实应用程序一样，需要在测试中使用依赖注入。原始应用程序执行此操作。下面的答案目前还不够，一个使用不是当前目标的模拟，另一个答案使用绕过问题目的的Controller。

注意：IDepartmentAppService依赖于IDepartmentRepository（也注入Startup类）和Automapper依赖关系。这就是为什么调用整个启动类的原因。

良好的资源：

如何使用构造函数依赖项注入对asp.net核心应用程序进行单元测试

Xunit项目中的依赖注入

Answer 1

使用下面的Custom Web Application Factory和ServiceProvider.GetRequiredService，随时编辑和优化答案

CustomWebApplicationFactory：

public class CustomWebApplicationFactory<TStartup> : WebApplicationFactory<TStartup> where TStartup : class
{
    protected override void ConfigureWebHost(IWebHostBuilder builder)
    {
        builder.ConfigureAppConfiguration((hostingContext, configurationBuilder) =>
        {
            var type = typeof(TStartup);
            var path = @"C:\\OriginalApplication";

            configurationBuilder.AddJsonFile($"{path}\\appsettings.json", optional: true, reloadOnChange: true);
            configurationBuilder.AddEnvironmentVariables();
        });

        // if you want to override Physical database with in-memory database
        builder.ConfigureServices(services =>
        {
            var serviceProvider = new ServiceCollection()
                .AddEntityFrameworkInMemoryDatabase()
                .BuildServiceProvider();

            services.AddDbContext<ApplicationDBContext>(options =>
            {
                options.UseInMemoryDatabase("DBInMemoryTest");
                options.UseInternalServiceProvider(serviceProvider);
            });
        });
    }
}

整合测试：

public class DepartmentAppServiceTest : IClassFixture<CustomWebApplicationFactory<OriginalApplication.Startup>>
{
    public CustomWebApplicationFactory<OriginalApplication.Startup> _factory;
    public DepartmentAppServiceTest(CustomWebApplicationFactory<OriginalApplication.Startup> factory)
    {
        _factory = factory;
        _factory.CreateClient();
    }

    [Fact]
    public async Task ValidateDepartmentAppService()
    {      
        using (var scope = _factory.Server.Host.Services.CreateScope())
        {
            var departmentAppService = scope.ServiceProvider.GetRequiredService<IDepartmentAppService>();
            var dbtest = scope.ServiceProvider.GetRequiredService<ApplicationDBContext>();
            dbtest.Department.Add(new Department { DepartmentId = 2, DepartmentCode = "123", DepartmentName = "ABC" });
            dbtest.SaveChanges();
            var departmentDto = await departmentAppService.GetDepartmentById(2);
            Assert.Equal("123", departmentDto.DepartmentCode);
        }
    }
}

资源：

https://docs.microsoft.com/zh-cn/aspnet/core/test/integration-tests?view=aspnetcore-2.2

https://fullstackmark.com/post/20/painless-integration-testing-with-aspnet-core-web-api

Answer 2

您正在混合单元测试和集成测试。TestServer是用于集成测试的，如果您想重用Startup类以避免再次注册依赖项，则应使用HttpClient并通过HTTP调用使用的控制器和操作IDepartmentAppService。

如果要进行单元测试，则需要设置DI并注册所有需要的依赖项以进行测试IDepartmentAppService。

通过测试治具使用DI：

public class DependencySetupFixture
{
    public DependencySetupFixture()
    {
         var serviceCollection = new ServiceCollection();
         serviceCollection.AddDbContext<SharedServicesContext>(options => options.UseInMemoryDatabase(databaseName: "TestDatabase"));
         serviceCollection.AddTransient<IDepartmentRepository, DepartmentRepository>();
         serviceCollection.AddTransient<IDepartmentAppService, DepartmentAppService>();

         ServiceProvider = serviceCollection.BuildServiceProvider();
    }

    public ServiceProvider ServiceProvider { get; private set; }
}

public class DepartmentAppServiceTest : IClassFixture<DependencySetupFixture>
{
    private ServiceProvider _serviceProvide;

    public DepartmentAppServiceTest(DependencySetupFixture fixture)
    {
        _serviceProvide = fixture.ServiceProvider;
    }

    [Fact]
    public async Task Get_DepartmentById_Are_Equal()
    {
        using(var scope = _serviceProvider.CreateScope())
        {   
            // Arrange
            var context = scope.ServiceProvider.GetServices<SharedServicesContext>();
            context.Department.Add(new Department { DepartmentId = 2, DepartmentCode = "123", DepartmentName = "ABC" });
            context.SaveChanges();

            var departmentAppService = scope.ServiceProvider.GetServices<IDepartmentAppService>();

            // Act
            var departmentDto = await departmentAppService.GetDepartmentById(2);

            // Arrange
            Assert.Equal("123", departmentDto.DepartmentCode);           
        }
    }
}

在单元测试中使用依赖注入不是一个好主意，您应该避免这种情况。顺便说一句，如果您不想重复自己的注册依赖项，则可以将DI配置包装在另一个类中，并在所需的任何位置使用该类。

通过Startup.cs使用DI：

public class IocConfig
{
    public static IServiceCollection Configure(IServiceCollection services, IConfiguration configuration)
    {
         serviceCollection
            .AddDbContext<SomeContext>(options => options.UseSqlServer(configuration["ConnectionString"]));
         serviceCollection.AddScoped<IDepartmentRepository, DepartmentRepository>();
         serviceCollection.AddScoped<IDepartmentAppService, DepartmentAppService>();
         .
         .
         .

         return services;
    }
}

在Startup类和ConfigureServices方法中只需使用IocConfig类：

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }

    public void ConfigureServices(IServiceCollection services)
    {
         IocConfig.Configure(services, configuration);

         services.AddMvc();
         .
         .
         .

如果你不想使用IocConfig类，变化ConfigureServices中的Startup类：

public IServiceCollection ConfigureServices(IServiceCollection services)
{
     .
     .
     .
     return services;

在测试项目重用IocConfig或Startup类中：

public class DependencySetupFixture
{
    public DependencySetupFixture()
    {
          var builder = new ConfigurationBuilder()
                .SetBasePath(Directory.GetCurrentDirectory())
                .AddJsonFile("appsettings.json", false, true));
         configuration = builder.Build();

         var services = new ServiceCollection();

         // services = IocConfig.Configure(services, configuration)
         // or
         // services = new Startup(configuration).ConfigureServices(services);

         ServiceProvider = services.BuildServiceProvider();
    }

    public ServiceProvider ServiceProvider { get; private set; }
}

并在测试方法中：

[Fact]
public async Task Get_DepartmentById_Are_Equal()
{
    using (var scope = _serviceProvider.CreateScope())
    {
        // Arrange
        var departmentAppService = scope.ServiceProvider.GetServices<IDepartmentAppService>();

        // Act
        var departmentDto = await departmentAppService.GetDepartmentById(2);

        // Arrange
        Assert.Equal("123", departmentDto.DepartmentCode);
    }
}

Answer 3

当你测试的时候。您需要使用模拟库或直接在构造函数上注入您的服务，即。

public DBContext context;
public IDepartmentAppService departmentAppService;

/// Inject DepartmentAppService here
public DepartmentAppServiceTest(DepartmentAppService departmentAppService)
{
    this.departmentAppService = departmentAppService;
}