Golang REST API: Handling Undefined vs. Null Attributes in JSON PATCH Requests with Gin and Validator

Introduction In the realm of REST APIs, particularly those built with Golang, Gin, and Validator, the distinction between undefined and null attributes in JSON payloads is not just a nuance—it’s a critical operational requirement. This distinction directly impacts how data is manipulated during PATCH requests, where the intent behind an attribute’s absence or explicit nullification must be unambiguously interpreted. Failure to differentiate these states can lead to data inconsistencies, loss of critical information, and compromised system integrity, as the API may incorrectly overwrite, delete