UpdateRecord and arrays

[Robert R. Bruno]

Is there a way to use UpdateRecord to update the value of a record that is
an array? In the example we have, we'd like to take a string from one field
in the record which is a string and copy it into another field that is an
array field but currently is null in the record.  So something like:

Input:

{  "test": "test1", "test_array": null}

Desired output:

{  "test": "test1", "test_array": ["test1"] }

We were going to look into if joltransform can do it if UpdateRecord can't.

Thanks!

Robert