Support ChangeCase on nested fields

[wijnanjo]

I'm dumping a nested structure into MongoDB and I'd like to apply lowercase on all fieldnames, also the nested fields. The current ChangeCase transformation only applies to the first level fields.

[feamcor]

I have a slightly different use case...

Consider a CDC record from Debezium.
The record has many metadata fields on first level, plus before and/or after fields that contains the columns and their before/after values depending on the transaction (insert/update/delete).
I would like to have changeCase applied only to the inner object of the before and after fields.

Without changeCase transformation:

{"metadata1":"value","metadata2":"value","before": {"col1":"val1","col2":"val2"}}

After changeCase transformation (e.g. "transforms.changeCase.fields.unwrap":"before,after"):

{"metadata1":"value","metadata2":"value","before": {"COL1":"val1","COL2":"val2"}}