CODEWITHSUNDEEP
c#moq
Damian
Damian

Reputation: 4651

Mock member variables

How do can I mock a member variables of a class?

It seems this FooA() is never called.

Note: I am beginner in moq (and rusty in C#) so please bear with me ;-)

Unhandled Exception: Moq.MockVerificationException: The following setups were not matched: IA a => a.FooA()

Here is the source code:

using Moq;

namespace TestMock
{
    interface IA {
        void FooA();
    }
    class A : IA {
        public void FooA() { }
    }

    class B {
        public void FooB() {
            a.FooA();
        }
        IA a = new A();
    }

    class Program
    {
        static void Main(string[] args)
        {
            // Arrange
            var mockA = new Mock<IA>();
            mockA.Setup(a => a.FooA());
            var mockB = new Mock<B>();

            // Act
            B b = new B();
            b.FooB();

            // Assert
            mockA.VerifyAll();
        }
    }
}

Upvotes: 2

Views: 2635

Answers (1)

Nkosi
Nkosi

Reputation: 247561

B in its original form is tightly coupled to dependency IA which makes it difficult to mock when testing.

Refactor B to depend on IA via constructor injection. (Explicit Dependencies Principle)

class B {
    IA a;

    public B(IA a) {
        this.a = a;
    }

    public void FooB() {
        a.FooA();
    }
}

Now inject the mocked dependency in the test and verify behavior

[TestMethod]
public void TestMoq() {
    // Arrange
    var mockA = new Mock<IA>();
    mockA.Setup(a => a.FooA());

    // Act
    B b = new B(mockA.Object);
    b.FooB();

    // Assert
    mockA.VerifyAll();
}

Upvotes: 2

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