[BUG] EventGridPublisherClient.SendEventsAsync fails if event handler function receives single EventGridEvent

Given the following Azure Functions v3 precompiled function:

[FunctionName("event-handle")]
public void HandleAsync([EventGridTrigger] EventGridEvent e, ILogger logger)
{
   logger.LogInformation(e.Subject);
}

And an Event Grid Domain (with no custom topic) with a Domain-Scoped Event Subscription (that basically handles every event with no filters whatesoever):

When using the code shown in PublishEventsToTopic to send all events in a batch:

await client.SendEventsAsync(eventsList);

the code fails with:

This resource is configured to receive event in 'EventGridEvent' schema. 
The JSON received does not conform to the expected schema. Token Expected: StartObject, Actual Token Received: EndArray. 

If the code is changed to send each event individually, delivery succeeds.

Expected behavior I would expect the batching on the client to have no impact on how the handling function is authored, and automatically invoke the function multiple times for each sent event.

Environment:

• Azure.Messaging.EventGrid 4.3.0
• Hosted Azure Functions v3 runtime
• Visual Studio 16.10

[jsquire]

Thank you for your feedback. Tagging and routing to the team member best able to assist.

[JoshLove-msft]

Hi @kzu, We are sorry that you are experiencing trouble here. The stable EventGrid functions bindings still rely on the old Microsoft.Azure.EventGrid library, which is why you are seeing this behavior. There is a beta EventGrid binding that uses the new models defined in Azure.Messaging.EventGrid - https://www.nuget.org/packages/Microsoft.Azure.WebJobs.Extensions.EventGrid/3.0.0-beta.3 If you would like to try it out, things should work more smoothly. Additionally, we will have a stable release of the EventGrid binding in the coming months that you can try.