NSubstitute: Mocking properties

Question

I created substitutes for Person and AddressBook classes in the unit Test. The AddressBook class contains properties of type Person and name: SamplePerson.

public interface IAddressBook
{
    Person SamplePerson { get; set; }
}

public class AddressBook : IAddressBook
{
    public Person SamplePerson { get; set; }

    public AddressBook(Person samplePerson)
    {
        SamplePerson = samplePerson;
    }
}

public interface IPerson
{
    string GetName(string name);
}

public class Person : IPerson
{
    public string GetName(string name)
    {
        return name;
    }
}

public void TestMethod1()
{
    var personMock = Substitute.For<IPerson>();
    var addressBookMock = Substitute.For<IAddressBook>();

    addressBookMock.SamplePerson.Returns(personMock); //not working
    addressBookMock.SamplePerson = personMock; //not working
    addressBookMock.SamplePerson = (Person)personMock; //not working

    Assert.AreEqual(1, 1);
}

I would like to assign mock variable of Person type to propeties of mock variable of type AddressBook.

Is this possible?

`SamplePerson` property returns `Person` and not `IPerson` so your attempt to return `IPerson` will not work. Either mock the class or return an actual instance. — Nkosi, Jul 18 '18 at 11:56
But it is impossible to mock Class using NSubsitute. I am receiving: ,,Could not find a parameterless contructor". — Piotr X, Jul 18 '18 at 12:00
Either mock the `Person` class or return an actual instance. — Nkosi, Jul 18 '18 at 12:01

score 3 · Accepted Answer · answered Jul 18 '18 at 12:18

IAddressBook.SamplePerson property returns Person implementation and not IPerson interface, so your attempt to return IPerson will not work.

Either mock the Person class

var personMock = Substitute.For<Person>();
var addressBookMock = Substitute.For<IAddressBook>();
addressBookMock.SamplePerson.Returns(personMock);

or return an actual instance.

var person = new Person();
var addressBookMock = Substitute.For<IAddressBook>();
addressBookMock.SamplePerson.Returns(person);

NSubstitute: Mocking properties

1 Answers1