Feature request: Add HandleResultAsync

Hey everybody,

today I ran into a case where handling a result involved executing an async operation:

var policy = Policy<HttpResponseMessage>
                .HandleResult(response => response.Content.ReadAsStringAsync().Result.Contains("pattern"))
                .RetryAsync(retries, (exception, retryCount, context) => doSomething());

So as you can see, I need to access the content of the response to decide whether to retry or not. Unfortunately the only way to parse it is with async methods. So to get it to work with HandleResult, I need to add Result, which is not recommended and might lead to problems.

The obvious solution would be to add a HandleResultAsync method to Polly, similar to e.g. Retry and RetryAsync. I haven’t looked at the code myself yet, but maybe it’s not too complicated to add the async counterpart and I think it would enable support for a quite frequent use case.

Anyways, I love using Polly. It makes things a lot easier, so thanks for that! 😃

[reisenberger]

For anyone exploring this problem, this Stackoverflow answer explores a possible solution to a similar case.

[rmandvikar]

With nested retry policies, wouldn’t it retry retryCount ^ 2 times instead of just retryCount times?