How to test a class with delegate in constructor using Moq - moq

Question

Can someone explain to me how to create an instance of this component in a Moq TestMethod? Here is the definition of the class. I need to test the ProcessAutomaticFillRequest method.
public class AutomaticDispenserComponent : IAutomaticDispenserComponent
{
private readonly Lazy<IMessageQueueComponent> _messageQueueComponent;
protected IMessageQueueComponent MessageQueueComponent { get { return _messageQueueComponent.Value; } }
public AutomaticDispenserComponent(Func<IMessageQueueComponent> messageQueueComponentFactory)
{
_messageQueueComponent = new Lazy<IMessageQueueComponent>(messageQueueComponentFactory);
}
public void ProcessAutomaticFillRequest(FillRequestParamDataContract fillRequestParam)
{
if (fillRequestParam.PrescriptionServiceUniqueId == Guid.Empty)
throw new InvalidOperationException("No prescription service was specified for processing fill request.");
if (fillRequestParam.Dispenser == null)
throw new InvalidOperationException("No dispenser was specified for processing fill request.");
var userContext = GlobalContext.CurrentUserContext;
var channel = string.Format(Channel.FillRequest, userContext.TenantId,
userContext.PharmacyUid, fillRequestParam.Dispenser.DeviceAgentUniqueId);
NotificationServer.Publish(channel, fillRequestParam);
}
Here is how I started my test, but I don't know how to create an instance of the component:
[TestMethod]
[ExpectedException(typeof (InvalidOperationException))]
public void FillRequestFailsWhenPrescriptionServiceUniqueIdIsEmpty()
{
// How do I create an instance of automatiqueDispenserComponent here
// since there is Func as constructor parameter?
var fillRequestParam = new FillRequestParamDataContract
{
PrescriptionServiceUniqueId = Guid.Empty
};
_automaticDispensercomponent.ProcessAutomaticFillRequest(fillRequestParam);
// ...
}

Answer 1

Updated the answer based on the comments below. You need to mock the Func parameter for the test.
[TestMethod]
[ExpectedException(typeof(InvalidOperationException))]
public void FillRequestFailsWhenPrescriptionServiceUniqueIdIsEmpty()
{
var mockMsgQueueComponent = new Mock<Func<IMessageQueueComponent>>();
var _automaticDispensercomponent = new AutomaticDispenserComponent
(mockMsgQueueComponent.Object);
var fillRequestParam = new FillRequestParamDataContract
{
PrescriptionServiceUniqueId = Guid.Empty
};
_automaticDispensercomponent.ProcessAutomaticFillRequest(fillRequestParam);
}