how to fake / unit test Azure Storage Queue?

Question

I am trying to find a way to test some code I have that will query an azure storage queue. For now, I have been asked to create my own local in memory queue class that simulates the upstream Azure queue. At this point, I'm trying to see if I can create a sample message in a fake queue so the callee of my class has some data to work with.

So I'm trying to do something like this:

using Azure.Storage.Queues.Models;
namespace Widgets.Tests.Queues
{
    public class InMemoryAzureMessageQueue : IAzureQueueClient
    {
        public string DequeueMessage(QueueMessage message)
        {
            throw new System.NotImplementedException();
        }

        public QueueMessage[] GetMessages()
        {
           //pseudocode
           QueueMessage qm = new QueueMessage();
           QueueMessage[] listqm = new QueueMessage[];
           qm.messageID = xxx;
           qm.messageBody = "hello";

           listqm.add(qm);
           return listqm;

        }

        public bool HasMesssages()
        {
            return true; 
        }
    }
 }

When I try to create "qm" I'm getting the following error message: 'QueueMessage' does not contain a constructor that takes 0 arguments

What I've Tried So Far:

I have tried to "go to defintion" while clicking on QueueMessage just to see what the constructor looks like. But when I do, I get an error saying that there is no definition found.

The description of the class says this:

The object returned in the QueueMessageList array when calling Get Messages on a Queue.

Maybe I can't just create a message like this?

I'm really green at .NET and all things Azure. Any tips would be appreciated.

Answer 1

The QueueMessage class does not contain an accessible constructor. You can however build a message using the QueuesModelFactory , which was designed for mocking these messages:

public QueueMessage[] GetMessages()
{
    QueueMessage qm = QueuesModelFactory.QueueMessage(
        messageId: "xxx",
        popReceipt: "",
        messageText: "hello",
        dequeueCount: 0);
    QueueMessage[] listqm = new QueueMessage[1];

    listqm[0] = qm;
    return listqm;
}