Allow admins/auditors to read private personal snippets

app/policies/personal_snippet_policy.rb

@@ -29,4 +29,6 @@ class PersonalSnippetPolicy < BasePolicy
   rule { anonymous }.prevent :comment_personal_snippet
   rule { can?(:comment_personal_snippet) }.enable :award_emoji
+
+  rule { full_private_access }.enable :read_personal_snippet
 end

changelogs/unreleased/51754-admin-view-private-personal-snippets.yml

+---
+title: Allow users with full private access to read private personal snippets.
+merge_request: 24560
+author:
+type: fixed

spec/models/event_spec.rb

@@ -399,10 +399,7 @@ describe Event do
           expect(event.visible_to_user?(nil)).to be_falsy
           expect(event.visible_to_user?(non_member)).to be_falsy
           expect(event.visible_to_user?(author)).to be_truthy
-
-          # It is very unexpected that a private personal snippet is not visible
-          # to an instance administrator. This should be fixed in the future.
-          expect(event.visible_to_user?(admin)).to be_falsy
+          expect(event.visible_to_user?(admin)).to be_truthy
         end
       end
     end

spec/policies/personal_snippet_policy_spec.rb

@@ -128,6 +128,17 @@ describe PersonalSnippetPolicy do
       end
     end
+    context 'admin user' do
+      subject { permissions(admin_user) }
+
+      it do
+        is_expected.to be_allowed(:read_personal_snippet)
+        is_expected.to be_disallowed(:comment_personal_snippet)
+        is_expected.to be_disallowed(:award_emoji)
+        is_expected.to be_disallowed(*author_permissions)
+      end
+    end
+
     context 'external user' do
       subject { permissions(external_user) }