如何对依赖基类的方法进行单元测试

Question

我有一个下面的类，它有基类，我正在尝试编写单元测试。

public class CarService : ServiceBase, IProvisioningService
{
private IAuditRepository _repository;
public CarService(IHostingFactory hostingFactory) : base(name, hostingFactory)
{         
}
public override void DoWork()
{
if (_repository == null)
{
//its calling the base method.
_repository = CurrentContext.ContainerFactory.GetInstance<IAuditRepository>();                  
try
{
_repository.Insert("something");
}
catch (Exception ex)
{
}
}       
}
}

CurrentContext.ContainerFactory是基类的一部分。CurrentContext.ContainerFactory抛出null异常。如何为这些类创建Mock？

接口是单元测试必须的吗？

使用基类更新

public abstract class ServiceBase : IServiceBase
{
public HostingContext CurrentContext { get; }
public string ServiceName { get; }
protected ServiceBase(string serviceName, IHostingFactory hostingFactory)
{
ServiceName = serviceName;
_stopSignal = false;
CurrentContext = hostingFactory.CreateContext(serviceName);
Logger = CurrentContext.LoggerInstance;
}
}

HostingContext类

public class HostingContext
{
public HostingContext(
Func<string, ILogger> loggerFactory,
string serviceName, 
string connString): this(loggerFactory(contextName),serviceName, connString, new ContainerFactory())
{}
}

单元测试类

MockRepository repository = new MockRepository(MockBehavior.Default);
var containerFactoryMock = repository.Create<IContainerFactory>();
var auditRepositoryMock = repository.Create<IAuditRepository>();
var hostingFactoryMock = repository.Create<IHostingFactory>();
var hostingContextMock = new HostingContext("Sample", "ConnString",containerFactoryMock.Object);

hostingFactoryMock.Setup(factory => factory.CurrentContext(It.IsAny<string>()))
.Returns(hostingContextMock);
CarService carService = new CarService(hostingFactoryMock.Object);
carService.Work();

Answer 1

您没有设置容器工厂的行为，因此当您调用.GetInstance<IAuditRepository>()时，它将返回null，因此您的错误。

为测试中的类提供必要的依赖项，以允许测试一直进行到完成。

//Arrange
var repository = new MockRepository(MockBehavior.Default);
var containerFactoryMock = repository.Create<IContainerFactory>();
var auditRepositoryMock = repository.Create<IAuditRepository>();
var hostingFactoryMock = repository.Create<IHostingFactory>();
var loggerMock = repository.Create<ILogger>();
var hostingContextMock = new HostingContext(loggerMock, "Sample", "ConnString",containerFactoryMock.Object);
hostingFactoryMock
.Setup(_ => _.CreateContext(It.IsAny<string>()))
.Returns(hostingContextMock);
containerFactoryMock
.Setup(_ => _.GetInstance<IAuditRepository>())
.Returns(auditRepositoryMock);
CarService carService = new CarService(hostingFactoryMock.Object);
//Act
carService.Work();
//Assert
auditRepositoryMock.Verify(_ => _.Insert(It.IsAny<string>()), Times.Once);