SignalR triggers and outputs do not work when using a non-default settingname for 'ConnectionStringSetting'

[fgheysels]

I've created an Azure Function which has bindings to a serverless Azure SignalR resource. In the Azure SignalR resource, I've configured 'Upstream' to my Azure Function.

The Azure Function App contains multiple functions which have SignalR triggers or SignalR outputs, like this:

[FunctionName(nameof(SubscribeToDeviceAsync))]
public static async Task SubscribeToDeviceAsync(
    [SignalRTrigger("telemetry", "messages", nameof(SubscribeToDeviceAsync),
                    parameterNames: new string[]{ "deviceId"}, 
                    ConnectionStringSetting = "DeviceTelemetrySignalRConnectionString")] InvocationContext invocationContext,
    string deviceId,
    ILogger logger) {}

or

[FunctionName(nameof(TelemetryNotifier))]
public static async Task Run(
        [EventHubTrigger("%TelemetryEventHub_Name%", Connection = "TelemetryEventHub_ConnectionString", ConsumerGroup = "%TelemetryNotifier_ConsumerGroup%")]
        EventData[] events,
        [SignalR(ConnectionStringSetting = "DeviceTelemetrySignalRConnectionString", HubName = "telemetry")]
        IAsyncCollector<SignalRMessage> signalRMessages,
        ILogger log)

Note that I've specified a custom setting-name for the SignalR connectionstring setting (as is documented here ) When I run my Function, I get InvalidOperationExceptions which say:

Exception while executing function: TelemetryNotifier The SignalR Service connection string or endpoints are not set.

When I remove the ConnectionStringSetting from my bindings, and configure the function to have a setting named AzureSignalRConnectionString, then everything works.

[fgheysels]

It looks like the custom setting name on the output binding on IAsyncCollector works with the custom settingname.

When I call the SubscribeToDeviceAsync method however, which has the SignalRTrigger binding, I get the response:

Microsoft.AspNetCore.SignalR.HubException: 'The SignalR Service connection string or endpoints are not set.'

As soon as I change the SignalRTrigger binding (remove the ConnectionStringSetting property-name and add a setting AzureSignalRConnectionString to my Function configuration, the function works as expected.

[Y-Sindo]

ConnectionStringSetting for SignalRTrigger should work in traditional mode, like the sample you give. I am unable to reproduce the problem. Could you give a reproducible function project?

[fgheysels]

@Y-Sindo , I've created a sample project which can be found here.

[Y-Sindo]

Already reproduced the problem. invocationContext.GetGroupsAsync() method doesn't respect the ConnectionStringSetting. Will fix later.