maskPII

Partially masks a value while preserving some characters for debugging.

Used for parameters annotated with @PII (Personally Identifiable Information).

Masking behavior:

• null: Returns "null"

• Empty string: Returns ""

• String with 4 or fewer chars: Returns "****"

• Email (contains @): Masks local part, preserves domain (e.g., "jo***@example.com")

• Other strings: Shows first 2 and last 2 chars (e.g., "Jo***oe" for "JohnDoe")

• Other types: Converts to string and masks

Parameters