Include Exception Properties at FailureDetails via Custom Provider

[nytian]

Issue describing the changes in this PR

Add support for including exception properties at TaskFailureDetails via custom provider

Note: This PR won't work unless microsoft/durabletask-dotnet#474 is merged.

Pull request checklist

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[andystaples]

Looking mostly good - just one thing to discuss

[cgillum]

I'm a bit confused about why we mix JSON and protobuf together in the same payloads. I don't remember us doing this before, so maybe I'm missing some context.

[andystaples]

Comments

[andystaples]

Couple of questions about this

1. Why Newtonsoft objects specifically, and not other JSON library objects?
2. I notice we are not doing these Newtonsoft conversions in TaskFailureDetailsConverter.cs - is this deliberate?
3. Also, this may be generally unintuitive for customers who expect their JValue properties to be returned as JValue (or the string equivalent) and instead get some defined object.

[nytian]

I added these because, in the test case, some nested objects such as lists and dictionaries are serialized and deserialized as JSON values when passed from Worker.Extensions to WebJobs.Extensions. Therefore, we need to include this JSON block here.

For TaskFailureDetailsConverter, there’s no serialization or deserialization involved — it directly handles the object itself, so a JSON block isn’t needed there.

Yeah, if they specifically expect a JValue, we might be violating that here — but are there really many such cases? It seems that handling nested structures is more important overall. I’m fine with either approach, though. leave it as it-is for other folks to join the discussion..