Optimize system note visibility checking by hiding notes that

have been fully redacted and contain cross-project references.

The previous implementation relied on Note#cross_reference_not_visible_for?,
which essentially tries to render all the Markdown references in a system note
and only displays the note if the user can see the referring project. But this
duplicated the work that Banzai::NotesRenderer was doing already. Instead, for
each note we render, we memoize the number of visible user references and
use it later if it is available.

Improves #19273

1 files changed, 14 insertions, 0 deletions

diff --git a/spec/models/note_spec.rb b/spec/models/note_spec.rb
index 6549791f675..7d0697dab42 100644
--- a/spec/models/note_spec.rb
+++ b/spec/models/note_spec.rb
@@ -226,6 +226,20 @@ describe Note, models: true do
     it "returns false" do
       expect(note.cross_reference_not_visible_for?(private_user)).to be_falsy
     end
+
+    it "returns false if user visible reference count set" do
+      note.user_visible_reference_count = 1
+
+      expect(note).not_to receive(:reference_mentionables)
+      expect(note.cross_reference_not_visible_for?(ext_issue.author)).to be_falsy
+    end
+
+    it "returns true if ref count is 0" do
+      note.user_visible_reference_count = 0
+
+      expect(note).not_to receive(:reference_mentionables)
+      expect(note.cross_reference_not_visible_for?(ext_issue.author)).to be_truthy
+    end
   end
 
   describe 'clear_blank_line_code!' do