MethodCaller CallMethodTryAsync Errors

[richard-chamberlain]

I'm currently upgrading a Csla 4.6 project that uses ObjectFactory to Csla 10.
All DataPortal ObjectFactory async functions throws a NotSupportedException unless the return value is Task<object>.

I traced the issue to the function ThrowIfNotTaskTReturn in MethodCaller

static async Task<object?> ThrowIfNotTaskTReturn(object? returnValue, object objectType, string calledMethodName)
{
	if (returnValue is not Task<object?> t)
	{
		ThrowNotSupportedException(objectType, calledMethodName);
	}

	return await t.ConfigureAwait(false);
}

Any Suggestions?

Thanks,
Richard

[rockfordlhotka]

I'm pretty sure the object factory concept has always expected return values to be object. In CSLA 10 @StefanOssendorf did a massive amount of work to support nullable types (NRT), and so it makes sense that we'd now expect object? as the return type, because the code could return a null.

What is the problem you are encountering?

[richard-chamberlain]

Let me use samples to show the issue

//This Works. This is what I used in Csla 4.6
public PersonEdit Create()
{
    var bo = ApplicationContext.CreateInstanceDI<PersonEdit>();
	CheckRules(bo);
	MarkNew(bo);
    return bo;
}

//This Works (Return value Task<object?> or Task<object>)
public async Task<object?> Create()
{
    var bo = ApplicationContext.CreateInstanceDI<PersonEdit>();
    CheckRules(bo);
	MarkNew(bo);
    return await Task.FromResult(bo);
}

//This Fails (Return value Task<PersonEdit?> or Task<PersonEdit>)
public async Task<PersonEdit?> Create()
{
    var bo = ApplicationContext.CreateInstanceDI<PersonEdit>();
    CheckRules(bo);
	MarkNew(bo);
    return await Task.FromResult(bo);
}

[StefanOssendorf]

That is a bug.
Task<PersonEdit?> or Task<PersonEdit> should have matched is Task<object> or is Task<object?>.