c# - 如何使用 NSubstitute 框架验证接收到具有特殊类型的 AddSingleton

Question

我想模拟 IServiceCollection 以使用 Nsubstite 模拟库和 检查是否使用特定接口(interface)和具体类型调用了 AddSingleton xUnit.

这是我的单元测试:

[Fact] 
public checkIfServicesAddedTo_DI()
{
    var iServiceCollectionMock = Substitute.For<IServiceCollection>();
    var iConfiguration = Substitute.For<IConfiguration>();
    MatchServicesManager servicesManager = new MatchServicesManager();
    servicesManager.AddServices(iServiceCollectionMock, iConfiguration);

    iServiceCollectionMock.Received(1).AddSingleton(typeof(IMatchManager) , typeof(MatchManager));
}

这是实现:

public class MatchServicesManager : IServicesManager
{
    public void AddServices(IServiceCollection services, IConfiguration configuration)
    {
        services.AddSingleton<IMatchManager, MatchManager>();
    }
}

我希望测试成功，但它失败并出现以下错误:

NSubstitute.Exceptions.ReceivedCallsException : Expected to receiveexactly 1 call matching: Add(ServiceDescriptor) Actually received nomatching calls. Received 1 non - matching call(non - matchingarguments indicated with '*' characters): Add(*ServiceDescriptor *)

Answer 1

AddSingleton 是 IServiceCollection 的扩展方法。这使得模拟或验证变得更加困难。

考虑使用接口(interface)的实际实现，然后在执行被测方法后验证预期行为。

例如

public void checkIfServicesAddedTo_DI() {
    //Arrange
    var services = new ServiceCollection();// Substitute.For<IServiceCollection>();
    var configuration = Substitute.For<IConfiguration>();
    MatchServicesManager servicesManager = new MatchServicesManager();

    //Act
    servicesManager.AddServices(services, configuration);

    //Assert (using FluentAssertions)
    services.Count.Should().Be(1);
    services[0].ServiceType.Should().Be(typeof(IMatchManager));
    services[0].ImplementationType.Should().Be(typeof(MatchManager));
}