Fix duplicate filename displayed in design todos

app/helpers/todos_helper.rb

@@ -37,11 +37,12 @@ module TodosHelper
   end
 
   def todo_target_title(todo)
-    if todo.target
-      "\"#{todo.target.title}\""
-    else
-      ""
-    end
+    # Design To Dos' filenames are displayed in `#todo_target_link` (see `Design#to_reference`),
+    # so to avoid displaying duplicate filenames in the To Do list for designs,
+    # we return an empty string here.
+    return "" if todo.target.blank? || todo.for_design?
+
+    "\"#{todo.target.title}\""
   end
 
   def todo_parent_path(todo)

changelogs/unreleased/fix-design-todos-filename-duplication.yml

+---
+title: Fix duplicate filename displayed in design todos
+merge_request: 32274
+author: Arun Kumar Mohan
+type: fixed

spec/helpers/todos_helper_spec.rb

@@ -5,7 +5,7 @@ require 'spec_helper'
 describe TodosHelper do
   let_it_be(:user) { create(:user) }
   let_it_be(:author) { create(:user) }
-  let_it_be(:issue) { create(:issue) }
+  let_it_be(:issue) { create(:issue, title: 'Issue 1') }
   let_it_be(:design) { create(:design, issue: issue) }
   let_it_be(:note) do
     create(:note,
@@ -68,6 +68,41 @@ describe TodosHelper do
     end
   end
 
+  describe '#todo_target_title' do
+    context 'when the target does not exist' do
+      let(:todo) { double('Todo', target: nil) }
+
+      it 'returns an empty string' do
+        title = helper.todo_target_title(todo)
+        expect(title).to eq("")
+      end
+    end
+
+    context 'when given a design todo' do
+      let(:todo) { design_todo }
+
+      it 'returns an empty string' do
+        title = helper.todo_target_title(todo)
+        expect(title).to eq("")
+      end
+    end
+
+    context 'when given a non-design todo' do
+      let(:todo) do
+        create(:todo, :assigned,
+        user: user,
+        project: issue.project,
+        target: issue,
+        author: author)
+      end
+
+      it 'returns the title' do
+        title = helper.todo_target_title(todo)
+        expect(title).to eq("\"Issue 1\"")
+      end
+    end
+  end
+
   describe '#todo_target_path' do
     context 'when given a design' do
       let(:todo) { design_todo }