I have a Web API like this:

• it calls the IService.Get method which returns an IAsyncEnumerable<> data
• the Get method will return a success/failure indicator
• it returns the individual item and accumulate the success/failure numbers
• finally it return an object that contains the success and failure count

Code:

app.MapGet("/api/data", ([FromServices] IService s, CancellationToken cancellationToken) =>
    {
        return Func();

        async IAsyncEnumerable<dynamic> Func()
        {
            var success = 0;
            var fail = 0;

            await foreach (var x in s.Get(cancellationToken))
            {
                if (x.Item1)
                    success++;
                else
                    fail++;

                yield return new { success = x.Item1, id = x.Item2 };
            }

            yield return new { success, fail };
        }
    });

I have already get the code inside the IService.Get to be very reactive. But I am stuck at the final step.

In the API, I need to:

• return the raw data from Get
• accumulate and transform the raw data and return the final result

What reactive function could do this?