Merging node inputs discards null values

[vmaksimovski]

I was testing out the following decision with the inputs listed below. I believe there is an issue with how node inputs are combined when a JS UDF is used that implements a passthrough for its inputs. In particular, any key that has a null value seems to get discarded from the output dictionary or any object in the output dictionary.

Note that in the decision provided, function1 is trivial -- but it's possible that the user might want it to add a particular function output along with passing through its inputs via { ...inputs, udf_result}
test-null.json

Inputs:

{
    "b": null,
    "test": {
        "a": null
    }
}

Result:

{
  test: {},
}

Expected

{
    "b": null,
    "test": {
        "a": null
    }
}