visibility can now return "restricted"

What changed

Producer-side tools call this additive. It breaks exhaustive switches, strict parsers and generated client enums.

Affects visibility on issue-field reachable from 3 operations.

New value: restricted.

can now return "restricted"

Who is affected

Code that reads GitHub's issue-field objects, used by 3 GitHub operations.

Before and after

Code that breaks

switch (response.visibility) {
  // existing branches …
  // no branch for "restricted"
  default:
    throw new Error("unexpected visibility");
}

Based on GitHub’s published API specification. How severity is decided.