在集成测试ASP.NET Core Web API和EF Core时重新配置依赖关系

Question

我正在按照本教程
使用Entity Framework Core和SQL Server进行集成测试

我的代码看起来像这样

集成测试类

public class ControllerRequestsShould : IDisposable
{
    private readonly TestServer _server;
    private readonly HttpClient _client;
    private readonly YourContext _context;

    public ControllerRequestsShould()
    {
        // Arrange
        var serviceProvider = new ServiceCollection()
            .AddEntityFrameworkSqlServer()
            .BuildServiceProvider();

        var builder = new DbContextOptionsBuilder<YourContext>();

        builder.UseSqlServer($"Server=(localdb)\\mssqllocaldb;Database=your_db_{Guid.NewGuid()};Trusted_Connection=True;MultipleActiveResultSets=true")
            .UseInternalServiceProvider(serviceProvider);

        _context = new YourContext(builder.Options);
        _context.Database.Migrate();

        _server = new TestServer(new WebHostBuilder()
            .UseStartup<Startup>()
            .UseEnvironment(Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT")));
        _client = _server.CreateClient();
    }

    [Fact]
    public async Task ReturnListOfObjectDtos()
    {
        // Arrange database data
        _context.ObjectDbSet.Add(new ObjectEntity{ Id = 1, Code = "PTF0001", Name = "Portfolio One" });
        _context.ObjectDbSet.Add(new ObjectEntity{ Id = 2, Code = "PTF0002", Name = "Portfolio Two" });

        // Act
        var response = await _client.GetAsync("/api/route");
        response.EnsureSuccessStatusCode();


        // Assert
        var result = Assert.IsType<OkResult>(response);            
    }

    public void Dispose()
    {
        _context.Dispose();
    }

据我了解,该.UseStartUp方法确保TestServer使用我的启动类

我遇到的问题是,当我的法案声明被发现时

var response = await _client.GetAsync("/api/route");

我的启动类中出现连接字符串为空的错误.我认为我对这个问题的理解是,当我的控制器被客户端命中时,它会注入我的数据存储库,而数据存储库又会注入数据库上下文.

我想我需要将服务配置为该部分的一部分,new WebHostBuilder以便它使用在测试中创建的上下文.但我不知道该怎么做.

Startup.cs中的ConfigureServices方法

        public void ConfigureServices(IServiceCollection services)
    {
        // Add framework services
        services.AddMvc(setupAction =>
        {
            setupAction.ReturnHttpNotAcceptable = true;
            setupAction.OutputFormatters.Add(new XmlDataContractSerializerOutputFormatter());
            setupAction.InputFormatters.Add(new XmlDataContractSerializerInputFormatter());
        });

        // Db context configuration
        var connectionString = Configuration["ConnectionStrings:YourConnectionString"];
        services.AddDbContext<YourContext>(options => options.UseSqlServer(connectionString));

        // Register services for dependency injection
        services.AddScoped<IYourRepository, YourRepository>();
    }

Answer 1

@ ilya-chumakov的答案很棒.我只想补充一个选项

3.使用WebHostBuilderExtensions中的ConfigureTestServices方法.

方法ConfigureTestServices在Microsoft.AspNetCore.TestHost版本2.1中可用(在20.05.2018,它是RC1-final).它让我们可以用模拟覆盖现有的注册.

代码:

_server = new TestServer(new WebHostBuilder()
    .UseStartup<Startup>()
    .ConfigureTestServices(services =>
    {
        services.AddTransient<IFooService, MockService>();
    })
);

Answer 2

1.使用 WebHostBuilder.ConfigureServices

过了一段时间,我认为最简单的解决方案是WebHostBuilder.ConfigureServices一起使用WebHostBuilder.UseStartup<T>来覆盖和模拟Web应用程序的DI注册:

_server = new TestServer(new WebHostBuilder()
    .ConfigureServices(services =>
    {
        services.AddScoped<IFooService, MockService>();
    })
    .UseStartup<Startup>()
);

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        //use TryAdd to support mocking IFooService
        services.TryAddTransient<IFooService, FooService>();
    }
}

这里的关键是使用类中的TryAdd方法Startup.在原作之前WebHostBuilder.ConfigureServices调用,所以首先注册你的模拟.如果使用,则跳过实际服务的注册.StartupTryAdd

更多信息:运行ASP.NET核心应用程序的集成测试.

2.继承/新的启动类

创建TestStartup类以重新配置ASP.NET Core DI.您可以从中继承它Startup并仅覆盖所需的方法:

public class TestStartup : Startup
{
    public TestStartup(IHostingEnvironment env) : base(env) { }

    public override void ConfigureServices(IServiceCollection services)
    {
        //mock DbContext and any other dependencies here
    }
}

或者TestStartup可以从头开始创建以保持测试更清洁.

并指定它UseStartup来运行测试服务器:

_server = new TestServer(new WebHostBuilder().UseStartup<TestStartup>());

Сomplete大型示例:使用内存数据库集成测试您的asp .net核心应用程序.