Re-tested on Snapshot environment - found issue is fixed.
See attached screenshot:

Ready for PO review

Hey , I’m expecting this issue to be fixed on the back-end side.

Tested on Snapshot-2 environment - works as expected in general (when fields don’t have required subfields).
See attached screenshots:
MARC bib:

MARC authority:

But I’ve found a way how to work around validation of the required subfield. And looks like it should be handled on UI sided. So, please review following case:
1. Subfields “$a” and “$l” are marked as “required” for “245” field, in MARC bib validation rules.
2. User tries to save MARC bib field with empty “$l”, ex.:
- “$a Edit MARC bib without required standard and appended $l“ - in this case, record will not be saved because of error during saving on back-end side.
or with space only in “$l” subfield:
- “$a Edit MARC bib without required standard and appended $l “

Expected result: return error: “Fail: Subfield ‘l' is required."
Actual result: UI sends empty subfield to ‘validate’ endpoint, and it passes validation. My guess is that UI shouldn’t send an empty subfield.

the issue is fixed

Hi
Tested on Snapshot env, following issue found:
”400” error is returned by “validate” endpoint when MARC field doesn’t have required subfield.
Error message is: "An odd number of parameters were passed to buildMap; even amounts are needed to construct key-value pairs"
In following example, subfields “$a” and “$l” of “245” field are marked as required in MARC validation rules.

Configured MARC validation rule example:

Saving of the record without required subfields in “245” field:

Saving of the record with required subfields in “245” field: