Mock Non-Abstract and Non-Virtual Classes or Members
The advanced features supported in Telerik® JustMock enables you to mock any class or member, including non-virtual and non-abstract implementations. The mocking of non-abstract classes is also available in the free edition but it only supports mocking a concrete class with virtual methods. The commercial version also includes mocking of non-abstract and non-virtual members of classes.
The commercial edition allows you to mock concrete objects without having to change anything in their interface.
This is an elevated feature. Refer to this topic to learn more about the differences between the commercial and the free versions of Telerik JustMock.
Here is the example class we are going to use:
Sample setup
public class Customer
{
public Customer()
{
throw new NotImplementedException("Constructor");
}
public string Name { get; set; }
public int GetNumberOfOrders()
{
throw new NotImplementedException();
}
public int GetNumberOfOrders(bool includeCompleted)
{
throw new NotImplementedException();
}
public void AddOrder(string productName)
{
throw new NotImplementedException();
}
public delegate void OrderAddedEventHandler(bool added);
public event OrderAddedEventHandler OnOrderAddedCallback;
}
Public Class Customer
Public Sub New()
Throw New NotImplementedException("Constructor")
End Sub
Public Property Name As String
Public Function GetNumberOfOrders() As Integer
Throw New NotImplementedException()
End Function
Public Function GetNumberOfOrders(ByVal includeCompleted As Boolean) As Integer
Throw New NotImplementedException()
End Function
Public Sub AddOrder(ByVal productName As String)
Throw New NotImplementedException()
End Sub
Public Delegate Sub OrderAddedEventHandler(ByVal added As Boolean)
Public Event OnOrderAddedCallback As OrderAddedEventHandler
End Class
Important
To use this kind of object mocking, you first need to go to elevated mode by enabling Telerik JustMock from the menu. Learn how to do that in the How to Enable/Disable Telerik JustMock topic.
Arrange Property
You can arrange the property get and set even when the property is not marked as abstract or virtual.
Example 1: Mock concrete implementation of property getter
[TestMethod]
public void ShouldSetupACallToAFinalProperty()
{
// Arrange
var customerMock = Mock.Create<Customer>();
Mock.Arrange(() => customerMock.Name).Returns("TestName");
// Act
var actual = string.Empty;
actual = customerMock.Name;
// Assert
Assert.AreEqual("TestName", actual);
}
<TestMethod>
Public Sub ShouldSetupACallToAFinalProperty()
' Arrange
Dim customerMock = Mock.Create(Of Customer)()
Mock.Arrange(Function() customerMock.Name).Returns("TestName")
' Act
Dim actual = String.Empty
actual = customerMock.Name
' Assert
Assert.AreEqual("TestName", actual)
End Sub
Example 2 defines that setting the final customerMock.Name property to any string value other than "TestName" will cause an exception of type StrictMockException to be thrown.
If you would like to learn more about mocking properties, check the Mock Properties help topic.
Example 2: Mock concrete implementation of property setter
[TestMethod]
[ExpectedException(typeof(StrictMockException))]
public void ShouldAssertPropertySet()
{
// Arrange
var customerMock = Mock.Create<Customer>(Behavior.Strict);
Mock.ArrangeSet(() => customerMock.Name = "TestName");
// Act
customerMock.Name = "Sample";
}
<TestMethod>
<ExpectedException(GetType(StrictMockException))>
Public Sub ShouldAssertPropertySet()
' Arrange
Dim customerMock = Mock.Create(Of Customer)(Behavior.Strict)
Mock.ArrangeSet(Function() customerMock.Name = "TestName")
' Act
customerMock.Name = "Sample"
End Sub
Arrange Method
Note that here we are going to mock an instance of the Customer class in the same way as we would do that for non-abstract classes whose members are declared as virtual.
Example 3: Mock concrete implementation of class and its members
[TestMethod]
[ExpectedException(typeof(NotImplementedException))]
public void ShouldCallOriginalForNonVirtualExactlyOnce()
{
// Arrange
// Create a mock of the object
var customerMock = Mock.Create<Customer>();
// Arrange your expectations
Mock.Arrange(() => customerMock.GetNumberOfOrders()).CallOriginal().OccursOnce();
//Act
customerMock.GetNumberOfOrders();
//Assert
Mock.Assert(customerMock);
}
<TestMethod>
<ExpectedException(GetType(NotImplementedException))>
Public Sub ShouldCallOriginalForNonVirtualExactlyOnce()
' Arrange
' Create a mock of the object
Dim customerMock = Mock.Create(Of Customer)()
' Arrange your expectations
Mock.Arrange(Function() customerMock.GetNumberOfOrders()).CallOriginal().OccursOnce()
' Act
customerMock.GetNumberOfOrders()
' Assert
Mock.Assert(customerMock)
End Sub
Generic methods and classes can also be mocked. Check the Generics topic for more details on that functionality.
Arrange Method Overloads
The following example shows how to mock different overloads of the concrete implementation of a method. Customer.GetNumberOfOrders has two overloads - one without arguments and one with a boolean argument. Here we mock them both by Returns. In the first case, we return just the argument that has been passed. In the second case we return the sum of the two integer values. After that, we act by calling both overloads and assert what we have arranged.
Example 4: Mock concrete implementation of methods with overloads
[TestMethod]
public void ShouldAssertOnMethodOverload()
{
// Arrange
var customerMock = Mock.Create<Customer>();
Mock.Arrange(() => customerMock.GetNumberOfOrders()).Returns(30);
Mock.Arrange(() => customerMock.GetNumberOfOrders(Arg.Is(true))).Returns(10);
// Assert
Assert.AreEqual(customerMock.GetNumberOfOrders(), 30);
Assert.AreEqual(customerMock.GetNumberOfOrders(true), 10);
}
<TestMethod>
Public Sub ShouldAssertOnMethodOverload()
' Arrange
Dim customerMock = Mock.Create(Of Customer)()
Mock.Arrange(Function() customerMock.GetNumberOfOrders()).Returns(30)
Mock.Arrange(Function() customerMock.GetNumberOfOrders(Arg.Is)).Returns(10)
' Assert
Assert.AreEqual(customerMock.GetNumberOfOrders(), 30)
Assert.AreEqual(customerMock.GetNumberOfOrders(True), 10)
End Sub
Arrange Method Callbacks
In this sections, you will find how to use the Raises method to fire a callback and pass event arguments once a final method is called.
Example 5: Fire callback and pass event arguments when non-virtual method is called
[TestMethod]
public void ShouldAssertOnMethodCallbacks()
{
// Arrange
var customerMock = Mock.Create<Customer>();
Mock.Arrange(() => customerMock.AddOrder(Arg.IsAny<string>())).Raises(() => customerMock.OnOrderAddedCallback += null, true);
bool called = false;
customerMock.OnOrderAddedCallback += delegate (bool added)
{
called = added;
};
// Act
customerMock.AddOrder("test");
// Assert
Assert.IsTrue(called);
}
<TestMethod>
Public Sub ShouldAssertOnMethodCallbacks()
' Arrange
Dim customerMock = Mock.Create(Of Customer)()
Mock.Arrange(Function() customerMock.AddOrder(Arg.IsAny(Of String)())).Raises(Sub() AddHandler customerMock.OnOrderAddedCallback, Nothing, True)
Dim called As Boolean = False
AddHandler customerMock.OnOrderAddedCallback, Sub(added As Boolean) called = added
' Act
customerMock.AddOrder("test")
' Assert
Assert.IsTrue(called)
End Sub
More information on raising mocked events is available in the Basic Usage | Raise topic.