+function isActorRejectActivityValid (activity: any) {
+ return isBaseActivityValid(activity, 'Reject')
+}
+
+function isActorUpdateActivityValid (activity: any) {
+ normalizeActor(activity.object)
+
+ return isBaseActivityValid(activity, 'Update') &&
+ isActorObjectValid(activity.object)
+}
+
+function normalizeActor (actor: any) {
+ if (!actor || !actor.url) return
+
+ if (typeof actor.url !== 'string') {
+ actor.url = actor.url.href || actor.url.url
+ }
+
+ if (actor.summary && typeof actor.summary === 'string') {
+ actor.summary = truncate(actor.summary, { length: CONSTRAINTS_FIELDS.USERS.DESCRIPTION.max })
+
+ if (actor.summary.length < CONSTRAINTS_FIELDS.USERS.DESCRIPTION.min) {
+ actor.summary = null
+ }
+ }
+
+ return
+}
+
+function isValidActorHandle (handle: string) {
+ if (!exists(handle)) return false
+
+ const parts = handle.split('@')
+ if (parts.length !== 2) return false
+
+ return isHostValid(parts[1])
+}
+
+function areValidActorHandles (handles: string[]) {
+ return isArray(handles) && handles.every(h => isValidActorHandle(h))
+}
+