vtysh not returning valid json when xpath does not exist and specified json format

[rhagelstrom]

Description

When running the following to query an xpath that doesn't exist the result isn't json but the string "(null)". I would expect the output returned would be valid json.

show mgmt datastore-contents running xpath json

Version

10.4.3

How to reproduce

From vtysh run the following with an xpath that doesn't exist.

show mgmt datastore-contents running xpath json

Expected behavior

The value returned is a string
(null)

I'd expect valid json, maybe {}

Actual behavior

The output is not valid json
(null)

Additional context

No response

Checklist

• I have searched the open issues for this bug.
• I have not included sensitive information in this report.

[rhagelstrom]

When I say an xpath that doesn't exist, I mean an item that is not configured so the leaf node in operstate/configstate does not exist

[mjstapp]

yes, the pattern we try to use is that we send at least an empty json object. we'll see about getting this path cleaned up.