385 words (approximately 2 mins)

Overview

Credit: https://hamidmosalla.com/2017/08/03/moq-working-with-setupget-verifyget-setupset-verifyset-setupproperty/

Examples in these notes use this system:

public interface IPropertyManager
{
    string FirstName { get; set; }
    string LastName { get; set; }
    void MutateFirstName(string name);
}

public class PropertyManager : IPropertyManager
{
    public string FirstName { get; set; }
    public string LastName { get; set; }

    public void MutateFirstName(string name) => this.FirstName = name;
}

class PropertyManagerConsumer
{
    private readonly IPropertyManager _propertyManager;

    public PropertyManagerConsumer(IPropertyManager propertyManager) => _propertyManager = propertyManager;

    public void ChangeName(string name) => _propertyManager.FirstName = name;

    public string GetName() => return _propertyManager.FirstName;

    public void ChangeRemoteName(string name) => _propertyManager.MutateFirstName(name);
}

And this test arrangement:

var mock = new Mock<IPropertyManager>();

var sut = new PropertyManagerConsumer(mock.Object);

Property Chains

Also known as recursive mocks:

var mock = new Mock<HttpContextBase>();
mock.SetupGet(p => p.Response.Request.UserAgent).Returns("My Browser");

SetupGet (Getters)

Use SetupGet() to stub a property with a certain value and verify that the system under test sees it:

mock.SetupGet(m => m.FirstName).Returns("Jane");

Assert.IsTrue(sut.GetName() == "Jane");

A property stubbed with SetupGet() cannot later be changed. To do that, see SetupProperty() below.

SetupSet (Setters)

Use SetupSet() to set the expectation that, when the system under test runs, it sets the FirstName property of the mocked type to John via that property’s setter:

mock.SetupSet(m => m.FirstName = "John").Verifiable();

sut.ChangeName("John");

// Verify that the IPropertyManager's FirstName property was set to "John" via a call to the system under test's ChangeName method:
mock.Verify();

Or, if we didn’t call SetupSet(), we could use VerifySet() to the same effect:

sut.ChangeName("John");

// Verify that the IPropertyManager's FirstName property was set to "John" via a call to the system under test's ChangeName method:
mock.VerifySet(m => m.FirstName = "John");

Verify Some Method of the SUT Passes the Correct Argument

sut.ChangeRemoteName("Jack");

// ChangeRemoteName calls the PropertyManager's MutateFirstName method
// Verify that ChangeRemoteName sends the correct string to MutateFirstName
mock.Verify(m => m.MutateFirstName(It.Is<string>(a => a == "Jack")), Times.Once);

SetupProperty for Tracking Auto Properties

Use SetupProperty() to start “tracking” the sets/gets on a property (useful for automatic properties):

mock.SetupProperty(m => m.FirstName);
mock.Object.FirstName = "Jill";

Assert.IsTrue(mock.Object.FirstName == "Jill");

mock.Object.FirstName = "Julia";
Assert.IsTrue(mock.Object.FirstName == "Julia");

Without the call to SetupProperty(), the above assertions would fail.

SetupAllProperties to Track All Auto Properties

mock.SetupAllProperties();

mock.Object.FirstName = "John";
mock.Object.LastName = "Wick";

Assert.IsTrue(mock.Object.FirstName == "John");
Assert.IsTrue(mock.Object.LastName == "Wick");

Above, if we only used mock.SetupProperty(m => m.FirstName), the second assertion would fail because only the FirstName property is being tracked.