[.NET] Incorrect DURABLE2001 warning when an activity has no parameter.

[GillesTourreau]

Description

When an orchestrator call an activity with no parameters data, the warning DURABLE2001 is raised with the following message: CallActivityAsync is passing the incorrect type 'none' instead of 'FunctionContext' to the activity function 'GetData'.

To reproduce the warning of the analyzer:

public static class Function1
{
    [Function(nameof(Function1))]
    public static async Task<List<string>> RunOrchestrator(
        [OrchestrationTrigger] TaskOrchestrationContext context)
    {
        ILogger logger = context.CreateReplaySafeLogger(nameof(Function1));
        logger.LogInformation("Saying hello.");
        var outputs = new List<string>();

        outputs.Add(await context.CallActivityAsync<string>(nameof(GetData)));   // Here a warning DURABLE2001 is display.

        return outputs;
    }

    [Function(nameof(GetData))]
    public static string GetData([ActivityTrigger] FunctionContext executionContext)
    {
        return $"THE DATA !!!";
    }

    [Function("Function1_HttpStart")]
    public static async Task<HttpResponseData> HttpStart(
        [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequestData req,
        [DurableClient] DurableTaskClient client,
        FunctionContext executionContext)
    {
        ILogger logger = executionContext.GetLogger("Function1_HttpStart");

        // Function input comes from the request content.
        string instanceId = await client.ScheduleNewOrchestrationInstanceAsync(
            nameof(Function1));

        logger.LogInformation("Started orchestration with ID = '{instanceId}'.", instanceId);

        // Returns an HTTP 202 response with an instance management payload.
        // See https://learn.microsoft.com/azure/azure-functions/durable/durable-functions-http-api#start-orchestration
        return await client.CreateCheckStatusResponseAsync(req, instanceId);
    }
}

Remarks: The is no data passed as argument. Only a FunctionContext parameter is declared because we need at least one parameter to declare the activity binding with [ActivityTrigger].

Expected behavior

When we call the CallActivityAsync() method to an activity which take no parameters, no warning DURABLE2001 should be raised by the compiler.

Actual behavior

When we call the CallActivityAsync() method to an activity which take no parameters, a warning DURABLE2001 is display during the compilation.

Relevant source code snippets

There is a repository which contains a complete sample to reproduce the error : https://github.com/GillesTourreau/DurableAnalyzersIssueActivityWithFunctionContext

Known workarounds

Provide a description of any known workarounds you used.

App Details

• Durable Functions extension version (e.g. v1.8.3): v1.8.0
• Azure Functions runtime version (1.0 or 2.0): 4.0
• Programming language used: .NET / C#

[cgillum]

The activity function signature in your repro is actually not valid because FunctionContext is not a valid parameter for [ActivityTrigger].

    [Function(nameof(GetData))]
    public static string GetData([ActivityTrigger] FunctionContext executionContext)

To avoid this warning and potential confusion to other maintainers of your code, I suggest putting a dummy value for the [ActivityTrigger] parameter, like object unusedInput and making FunctionContext executionContext its own separate parameter without the [ActivityTrigger] attribute.

[GillesTourreau]

@cgillum

I tried this two approaches :

public static string GetData([ActivityTrigger] object unusedInput, FunctionContext executionContext)

and

public static string GetData([ActivityTrigger] object unusedInput)

Both raise a DURABLE2001 warning with the following message: CallActivityAsync is passing the incorrect type 'none' instead of 'object' to the activity function 'GetData'.

For your information, with previous versions of Microsoft.Azure.Functions.Worker.Extensions.DurableTask libraries (for example, the v1.2.3), we used a ActivityContext parameter instead of FunctionContext when we have no data to send to the activity.

public static string GetData([ActivityTrigger] ActivityContext context)

An with the v1.8.0 and using ActivityContext parameter, we obtain the following exception in the generated code:

So what is the best way to declare an activity which accept no data to receive from the orchestrator and will not raise a DURABLE2001 warning?

[cgillum]

@GillesTourreau thanks for the clarification. I agree this is a bug. We should not be issuing this warning if the caller is not passing any arguments to the activity call.

The reason for the exception that you're seeing is that the ActivityContext in this case is a completely unrelated type from the System.Diagnostics namespace. We don't have a replacement for IActivityContext in the .NET Isolated model, but I agree that we should add it.

[GillesTourreau]

The reason for the exception that you're seeing is that the ActivityContext in this case is a completely unrelated type from the System.Diagnostics namespace. We don't have a replacement for IActivityContext in the .NET Isolated model, but I agree that we should add it.

@cgillum, Sorry, but I used the wrong class 😂 as argument, it should be TaskActivityContext instead of ActivityContext. And there is no issue when using it (no exception), but still have the DURABLE2001 warning.