Function kind_of 

const fn kind_of(action: &Action) -> ActionKind

The ActionKind an Action value attempts.

Action::Replace(b) maps to ActionKind::Replace here even at Site::Object, where it also carries ActionKind::ReplaceObject. That is deliberate: this function answers what the hook returned, which is the ActionRefused event’s action field. The refusal comes from classify, which names ReplaceObject, and the two are compared against different things: the event field against what the hook returned, the refusal against the published table.