c# - 如何在 ASP.NET Core MVC 中对 RazorViewEngineOptions 进行单元测试？

Question

在从 ConfigureServices 调用的扩展方法中我正在添加 EmbeddedFileProvider 的实例至 RazorViewEngineOptions .我想测试它是否已添加，但我找不到如何获取 RazorViewEngineOptions实例。

这在应用程序运行时有效:

public void ConfigureServices(IServiceCollection services)
{
    services.AddMvc()
                  .SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
    services.AddMyServices(Configuration);
}

public static IServiceCollection AddMyServices(this IServiceCollection services, IConfiguration configuration)
{
    services.Configure<RazorViewEngineOptions>(options => 
    {
        options.FileProviders.Add(new EmbeddedFileProvider(typeof(MyClass).Assembly, "My.Namespace"));
    });

    return services;
}

但是我该如何测试呢？ NullReferenceException被扔在这里:

[Fact]
public void MyTest()
{
    var services = new ServiceCollection();
    var serviceProvider = services.BuildServiceProvider();

    MyServicesBuilder.AddMyServices(services, new Mock<IConfiguration>().Object);
    var razorOptions = serviceProvider.GetService<IOptions<RazorViewEngineOptions>>();

    Assert.Equal(1, razorOptions.Value.FileProviders.Where(x => x.GetType() == typeof(EmbeddedFileProvider)).Count());
}

我试过添加 services.AddMvc()或 services.AddSingleton<RazorViewEngineOptions>() .

我也试过调用 services.GetRequiredService<RazorViewEngineOptions>()但这会抛出 System.InvalidOperationException : No service for type 'Microsoft.Extensions.Options.IOptions'1[Microsoft.AspNetCore.Mvc.Razor.RazorViewEngineOptions

我也尝试过询问 RazorViewEngineOptions而不是 IOptions<RazorViewEngineOptions> .

Answer 1

在构建提供者之后添加到服务集合的任何内容，提供者都不会知道。

将所需的一切添加到服务集合中，然后才构建提供者来执行您的断言

例如

[Fact]
public void MyTest() {
    //Arrange
    var services = new ServiceCollection();
    services.AddOptions();

    IConfiguration config = new ConfigurationBuilder()
        // Call additional providers here as needed.
        //...
        .Build();

    //Act
    MyServicesBuilder.AddMyServices(services, config);
    //OR
    //services.AddMyServices(config);

    //Assert
    var serviceProvider = services.BuildServiceProvider();
    var razorOptions = serviceProvider.GetService<IOptions<RazorViewEngineOptions>>();

    Assert.NotNull(razorOptions);
    Assert.Equal(1, razorOptions.Value.FileProviders.Where(x => x.GetType() == typeof(EmbeddedFileProvider)).Count());
}