Fix for note duplication when restoring notes when changing codelist (#382)

* Refactor note addition in Value object

Introduce RetoreNote method to prevent duplicate notes.
The method checks for existing notes before adding a new one,
ensuring that notes with the same text, type, and mandatory
status are not duplicated. This enhances the integrity of
the notes associated with a Value object.

* Added unit test

Author: likp

PxWeb.UnitTests/Data/PaxiomFixUtilTests.cs

@@ -67,6 +67,33 @@ public void RestoreNotes_WhenNotesExist_ReturnsNotes()
             Assert.AreEqual(1, variable.Values[0].Notes.Count);
         }
 
+        [TestMethod]
+        public void RestoreNotes_WhenSameNoteExist_DoesNotAddNote()
+        {
+            // Arrange
+            var variable = new Variable("VAR1", "VAR1", PlacementType.Heading, 1);
+            var value = new Value("v1");
+            value.AddNote(new Note("My note", NoteType.Value, true));
+            PaxiomUtil.SetCode(value, "v1");
+            variable.Values.Add(value);
+            value = new Value("v2");
+            PaxiomUtil.SetCode(value, "v2");
+            variable.Values.Add(value);
+            value = new Value("v3");
+            PaxiomUtil.SetCode(value, "v3");
+            variable.Values.Add(value);
+            var notes = new Dictionary<string, Notes>();
+            var list = new Notes();
+            list.Add(new Note("My note", NoteType.Value, true));
+            notes.Add("v1", list);
+
+            // Act
+            PaxiomFixUtil.RestoreNotes(variable, notes);
+
+            // Assert
+            Assert.AreEqual(1, variable.Values[0].Notes.Count);
+        }
+
         [TestMethod]
         public void RestoreNotes_WhenNotesNotApplicable_ReturnsNotes()
         {

PxWeb/Code/Api2/DataSelection/PaxiomFixUtil.cs

@@ -31,12 +31,28 @@ public static void RestoreNotes(Variable variable, Dictionary<string, Notes> not
                 {
                     foreach (var note in notes[valueCode])
                     {
-                        value.AddNote(note);
+                        RetoreNote(value, note);
                     }
                 }
             }
         }
 
+        private static void RetoreNote(Value value, Note note)
+        {
+            if (value.Notes is null)
+            {
+                value.AddNote(note);
+            }
+            else
+            {
+                if (value.Notes.Any(n => n.Text == note.Text && n.Type == note.Type && n.Mandantory == note.Mandantory))
+                {
+                    return; // Note already exists
+                }
+                value.AddNote(note);
+            }
+        }
+
         public static Dictionary<string, Notes> ExtractNotes(Variable variable)
         {