HttpRequestMessage caught from the orchestrator does not contain the original exception content

[ggirard07]

Description

HttpRequestException thrown from an activity does not contain the original exception message when caught in the orchestrator.

I made a sample app to demonstrate the issue: https://github.com/ggirard07/DurableFunctionWithHttpRequestException

Expected behavior

Original message of the exception should be available in the ex.InnerException.Message property.

Actual behavior

Content of the ex.InnerException.Message property is always

Exception of type 'System.Net.Http.HttpRequestException' was thrown.

Relevant source code snippets

[FunctionName("DurableFunction")]
public static async Task<List<string>> RunOrchestrator( [OrchestrationTrigger] DurableOrchestrationContext context ILogger log)
{
    ...
    try
    {
        outputs.Add(await context.CallActivityAsync<string>("DurableFunction_Hello", "London"));
    }
    catch (FunctionFailedException ex)
    {
        //at that point, ex.InnerException.Message is no longer the original content
    }
    ...
}

[FunctionName("DurableFunction_Hello")]
public static string SayHello([ActivityTrigger] string name, ILogger log)
{
    throw new HttpRequestException("This is the message of my original HttpRequestException....");
}

Known workarounds

Provide a description of any known workarounds you used.

App Details

• Durable Functions extension version (e.g. v1.8.3): v1.8.3
• Azure Functions runtime version (1.0 or 2.0): v2.0.12555.0
• Programming language used: C#/dotnet

[fabio-muramatsu]

Hi,
I just hit this issue when testing durable functions. The FunctionFailedException that is caught by the orchestrator has an inner exception of the right type, but as mentioned by @ggirard07, the message and stack trace are not retained. @cgillum Are there any plans to change this behavior to retain the original contents of the exception thrown by the Activity?
The workaround that I'm considering is having the Activities return an object indicating success/failure, along with the exception.
Thank you!

[ConnorMcMahon]

I'm going to track this as a specific sub-case of an issue that would be solved by #314.