CODEWITHSUNDEEP
c#unit-testingmoq
JoanComasFdz
JoanComasFdz

Reputation: 3066

How to moq a property that will be indirectly modified?

I am trying to do a very simple thing: Set an initial value to a property, call a method which callback should modify the property value, and read the property at the end.

Class Test2 is using ITest1 to automatize some actions.

public interface ITest1
{
    decimal Value { get; set; }
    void Increment();
}

public class Test2
{
    ITest1 test1;
    public Test2(Itest1 test1)
    {
        this.test1 = test1;
    }

    public void Increment()
    {
        this.test1.Increment();
    }
    public Get()
    {
       return this.test1.Value;
    }
}

In order to achieve this behaviour I setted up this test:

[TestClass]
public class Test2Test
{
    private Test2 test2;
    private decimal value;

    [TestInitialize]
    public void Setup()
    {
        var test1Mock = new Mock<ITest1>();
        test1Mock.SetupGet(m => m.Value).Returns(value);
        test1Mock
            .Setup(m => m.Increment())
            .Callback(() => value++);

        this.test2= new Test2(test1Mock.Object);
    }

    [TestMethod]
    public void Get_Returns0()
    {
        Assert.AreEqual(0, this.test2.Get());
    }

    [TestMethod]
    public void Get_AfterIncrement_Returns1()
    {
        this.test2.Increment();
        Assert.AreEqual(1, this.test2.Get());
    }
}

The second test is returning always 0. Why is this happening?

Upvotes: 1

Views: 481

Answers (1)

JoanComasFdz
JoanComasFdz

Reputation: 3066

The solution is to return actions instead of variables as:

.Return(() => value) instead of .Return(value)

Answer found here.

Upvotes: 1

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