fix: improve api error handling for dashboards and folders (#111831)

pkg/services/folder/folderimpl/folder.go

@@ -1401,13 +1401,13 @@ func (s *Service) validateParent(ctx context.Context, orgID int64, parentUID str
 
 	// Create folder under itself is not allowed
 	if parentUID == UID {
-		return folder.ErrCircularReference
+		return folder.ErrCircularReference.Errorf("circular reference detected")
 	}
 
 	// check there is no circular reference
 	for _, ancestor := range ancestors {
 		if ancestor.UID == UID {
-			return folder.ErrCircularReference
+			return folder.ErrCircularReference.Errorf("circular reference detected")
 		}
 	}
 

pkg/services/folder/folderimpl/sqlstore.go

@@ -417,7 +417,7 @@ func (ss *FolderStoreImpl) GetHeight(ctx context.Context, foldrUID string, orgID
 			ele := queue[0]
 			queue = queue[1:]
 			if parentUID != nil && *parentUID == ele {
-				return 0, folder.ErrCircularReference
+				return 0, folder.ErrCircularReference.Errorf("circular reference detected")
 			}
 			folders, err := ss.GetChildren(ctx, folder.GetChildrenQuery{UID: ele, OrgID: orgID})
 			if err != nil {

pkg/services/folder/folderimpl/sqlstore_test.go

@@ -840,7 +840,7 @@ func TestIntegrationGetHeight(t *testing.T) {
 
 	t.Run("should failed when the parent folder exist in the subtree", func(t *testing.T) {
 		_, err = folderStore.GetHeight(context.Background(), parent.UID, orgID, &subTree[0])
-		require.Error(t, err, folder.ErrCircularReference)
+		require.Error(t, err, folder.ErrCircularReference.Errorf("circular reference detected"))
 	})
 }
 

pkg/services/folder/folderimpl/unifiedstore.go

@@ -298,7 +298,7 @@ func (ss *FolderUnifiedStoreImpl) GetHeight(ctx context.Context, foldrUID string
 			ele := queue[0]
 			queue = queue[1:]
 			if parentUID != nil && *parentUID == ele {
-				return 0, folder.ErrCircularReference
+				return 0, folder.ErrCircularReference.Errorf("circular reference detected")
 			}
 			folders, err := ss.GetChildren(ctx, folder.GetChildrenQuery{UID: ele, OrgID: orgID})
 			if err != nil {