azure-webjobs-sdk: Deserializing ServiceBusMessage to POCO fails

My setup:

• macOS 10.13.6
• VS Code Version 1.28.2
• Azure Functions Core Tools (2.1.725 Commit hash: 68f448fe6a60e1cade88c2004bf6491af7e5f1df)
• Function Runtime Version: 2.0.12134.0

Repro is here: https://github.com/ChristianWeyer/azure-functions-servicebus-serialization-repro

This is the scenario:

C# Azure Function 1: -HTTP Trigger -> creates a message and sends it into SB queue via output binding => Java Azure function: -SB queue trigger -> creates new message based on incoming message and sends it to another queue via SB queue output binding => C# Azure Function 2: -Service Bus queue trigger -> inspects received message… and does nothing 😉

The message coming from the Java function into C# Function 2 (via SB) cannot be deserialized through model binding - so this fails:

public static class NotifyClientsAboutOrderShipmentFunctions
{
    [FunctionName("NotifyClientsAboutOrderShipment")]
    public static void Run(
        [ServiceBusTrigger("shippingsinitiated", Connection = "ServiceBus")]
        ShippingCreatedMessage msg, // Issue with deserializing incoming message
        ILogger log)
    {
        log.LogInformation($"NotifyClientsAboutOrderShipment SB queue trigger function processed message: {msg}");
        
        var messageToNotify = new { orderId = msg.OrderId };

        // TODO: Notify users' clients through SignalR...
    }
}

Exception:

[02/11/2018 09:06:21] Executing 'NotifyClientsAboutOrderShipment' (Reason='New ServiceBus message detected on 'shippingsinitiated'.', Id=9b058fc4-b60b-4e50-aa1b-c10f97135767)
[02/11/2018 09:06:24] Executed 'NotifyClientsAboutOrderShipment' (Failed, Id=9b058fc4-b60b-4e50-aa1b-c10f97135767)
[02/11/2018 09:06:24] System.Private.CoreLib: Exception while executing function: NotifyClientsAboutOrderShipment. Microsoft.Azure.WebJobs.Host: Exception binding parameter 'msg'. System.Private.DataContractSerialization: There was an error deserializing the object of type Serverless.Messages.ShippingCreatedMessage. The input source is not correctly formatted. System.Private.DataContractSerialization: The input source is not correctly formatted.
[02/11/2018 09:06:24] MessageReceiver error (Action=UserCallback, ClientId=MessageReceiver1shippingsinitiated, EntityPath=shippingsinitiated, Endpoint=cw-serverless-microservices.servicebus.windows.net)
[02/11/2018 09:06:24] System.Private.CoreLib: Exception while executing function: NotifyClientsAboutOrderShipment. Microsoft.Azure.WebJobs.Host: Exception binding parameter 'msg'. System.Private.DataContractSerialization: There was an error deserializing the object of type Serverless.Messages.ShippingCreatedMessage. The input source is not correctly formatted. System.Private.DataContractSerialization: The input source is not correctly formatted.

Not too helpful with the missing details 😉

If I change the function to look like this (and do the deserialization manually), it works:

public static class NotifyClientsAboutOrderShipmentFunction
{
    [FunctionName("NotifyClientsAboutOrderShipment")]
    public static void Run(
        [ServiceBusTrigger("shippingsinitiated", Connection = "ServiceBus")]
        /*ShippingCreatedMessage*/ string msg, // Issue with deserializing incoming message
        ILogger log)
    {
        log.LogInformation($"NotifyClientsAboutOrderShipment SB queue trigger function processed message: {msg}");

        ShippingCreatedMessage message = JsonConvert.DeserializeObject<ShippingCreatedMessage>(msg);
        
        var messageToNotify = new { orderId = message.OrderId };

        // TODO: Notify users' clients through SignalR...
    }
}

This is the message being sent via the ‘response’ queue:

{
  "Id": "c497b524-5929-48e5-aa7e-1a5992678afb",
  "Created": "2018-11-02T09:15:20.000133Z",
  "OrderId": "9190338c-546d-4d44-a7f3-081d6563bfc8"
}

What is expected:

1. Automatic deserialization should properly work
2. If it does not work, a more detailed & more helpful exception message should be shown why it did not work

Thanks!