Multi tool use

Moq class with constructors ILogger and options netcore 2.1 vs2017 getting error

I need to mock a class that has parameters in the constructor by I cannot figure out how you do it using moq. It crashes

Constructor arguments cannot be passed for interface mocks.

See my attempt below:

[Fact]
public async Task MyTest()
{
var mySettings= GetMySettings();
var mySettingsOptions = Options.Create(mySettings);
var mockLogger = Mock.Of<ILogger<MyClass>>();


var mock=new Mock<IMyClass>(mySettings,mockLogger);
mock.Setup(x=>x.DoSomething(It.IsAny<string>().Returns("todo");
}


public class MyClass : IMyClass
{
private readonly ILogger<MyClass> logger;
private readonly MySettings mySettings;

public MyClass(IOptions<MySettings> settings,ILogger<MyClass>logger)
{
this.logger = logger;
this.mySettings = settings.Value;
}


public string DoSomething(string myarg)
{
//omitted
}

}


How do you do it? many thanks

EDITED

In order to mock repository and test the behaviour i also need to mock the other classes that have constructors in it. Hope makes sense

public class MyService:IMyService
{
private MyClass myclass;
private OtherClass otherClass;
private Repository repository;


public MyService(IRepository repository,IMyClass myclass,IMyOtherClass otherClass)
{
this.myclass=myClass;
this.otherClass=otherClass;
this.repository=repository;
}

public void DoStuff()
{
bool valid1=myclass.Validate(); //mock myclass
var valid2=otherClass.Validate(); //mock otherClass


if(Valid1 && valid2)
{
repository.GetSomething();//this is really what I am mocking
}
//etc..

}
}


2 Answers
2

It doesn't matter if your class constructor has parameters or not, because you're working with its mock object.

var mock = new Mock<IMyClass>();
mock.Setup(x=>x.DoSomething(It.IsAny<string>()).Returns("todo");


Then you can use this mock to your repository constructor:

var myService = new MyService(repositoryMock.Object, mock.Object, otherClassMock.Object);


You are getting this error because you are trying to create a mock of an interface (IMyClass in this case) with constructor values. It seems like you are trying to test the method in the class MyClass, therefore you should be creating a moq of this class.
To clarify change
var mock=new Mock<IMyClass>(mySettings,mockLogger); to var mock=new Mock<MyClass>(mySettings,mockLogger);

IMyClass

MyClass

var mock=new Mock<IMyClass>(mySettings,mockLogger);

var mock=new Mock<MyClass>(mySettings,mockLogger);

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