V15: Adding tests for INavigationQueryService.TryGetLevel() (#17375)

* Fixing implementation to return null as level when it cannot retrieve it

* Adding unit tests

src/Umbraco.Core/Services/Navigation/ContentNavigationServiceBase.cs

@@ -64,12 +64,13 @@ internal abstract class ContentNavigationServiceBase
     public bool TryGetSiblingsKeysInBin(Guid key, out IEnumerable<Guid> siblingsKeys)
         => TryGetSiblingsKeysFromStructure(_recycleBinNavigationStructure, key, out siblingsKeys);
 
-    public bool TryGetLevel(Guid contentKey, out int level)
+    public bool TryGetLevel(Guid contentKey, out int? level)
     {
         level = 1;
         Guid? parentKey;
         if (TryGetParentKey(contentKey, out parentKey) is false)
         {
+            level = null;
             return false;
         }
 
@@ -77,6 +78,7 @@ internal abstract class ContentNavigationServiceBase
         {
             if (TryGetParentKey(parentKey.Value, out parentKey) is false)
             {
+                level = null;
                 return false;
             }
 

src/Umbraco.Core/Services/Navigation/INavigationQueryService.cs

@@ -44,5 +44,5 @@ public interface INavigationQueryService
 
     bool TryGetSiblingsKeys(Guid key, out IEnumerable<Guid> siblingsKeys);
 
-    bool TryGetLevel(Guid contentKey, out int level);
+    bool TryGetLevel(Guid contentKey, out int? level);
 }

src/Umbraco.PublishedCache.HybridCache/PublishedContent.cs

@@ -137,7 +137,7 @@ internal class PublishedContent : PublishedContentBase
     {
         get
         {
-            INavigationQueryService? navigationQueryService = null;
+            INavigationQueryService? navigationQueryService;
             switch (_contentNode.ContentType.ItemType)
             {
                 case PublishedItemType.Content:
@@ -150,8 +150,13 @@ internal class PublishedContent : PublishedContentBase
                     throw new NotImplementedException("Level is not implemented for " + _contentNode.ContentType.ItemType);
             }
 
-            navigationQueryService.TryGetLevel(Key, out int level);
-            return level;
+            // Attempt to retrieve the level, returning 0 if it fails or if level is null.
+            if (navigationQueryService.TryGetLevel(Key, out var level) && level.HasValue)
+            {
+                return level.Value;
+            }
+
+            return 0;
         }
     }
 

tests/Umbraco.Tests.UnitTests/Umbraco.Core/Services/ContentNavigationServiceBaseTests.cs

@@ -486,6 +486,47 @@ public class ContentNavigationServiceBaseTests
         }
     }
 
+    [Test]
+    public void Cannot_Get_Level_From_Non_Existing_Content_Key()
+    {
+        // Arrange
+        var nonExistingKey = Guid.NewGuid();
+
+        // Act
+        var result = _navigationService.TryGetLevel(nonExistingKey, out var level);
+
+        // Assert
+        Assert.Multiple(() =>
+        {
+            Assert.IsFalse(result);
+            Assert.IsNull(level);
+        });
+    }
+
+    [Test]
+    [TestCase("E48DD82A-7059-418E-9B82-CDD5205796CF", 1)] // Root
+    [TestCase("C6173927-0C59-4778-825D-D7B9F45D8DDE", 2)] // Child 1
+    [TestCase("E856AC03-C23E-4F63-9AA9-681B42A58573", 3)] // Grandchild 1
+    [TestCase("A1B1B217-B02F-4307-862C-A5E22DB729EB", 3)] // Grandchild 2
+    [TestCase("60E0E5C4-084E-4144-A560-7393BEAD2E96", 2)] // Child 2
+    [TestCase("D63C1621-C74A-4106-8587-817DEE5FB732", 3)] // Grandchild 3
+    [TestCase("56E29EA9-E224-4210-A59F-7C2C5C0C5CC7", 4)] // Great-grandchild 1
+    [TestCase("B606E3FF-E070-4D46-8CB9-D31352029FDF", 2)] // Child 3
+    [TestCase("F381906C-223C-4466-80F7-B63B4EE073F8", 3)] // Grandchild 4
+    public void Can_Get_Level_From_Existing_Content_Key(Guid key, int expectedLevel)
+    {
+        // Act
+        var result = _navigationService.TryGetLevel(key, out var level);
+
+        // Assert
+        Assert.Multiple(() =>
+        {
+            Assert.IsTrue(result);
+            Assert.IsNotNull(level);
+            Assert.AreEqual(expectedLevel, level);
+        });
+    }
+
     [Test]
     public void Cannot_Move_Node_To_Bin_When_Non_Existing_Content_Key()
     {