Chore: Fix fetching the General folder when nested folders is set and improve error handling (#62951)

* Nested folders: Modify Get() not to fail fetching the General folder

* Add test

pkg/services/folder/folderimpl/folder.go

@@ -34,7 +34,7 @@ type Service struct {
 	features             featuremgmt.FeatureToggles
 	accessControl        accesscontrol.AccessControl
 
-	// bus is currently used to publish events that cause scheduler to update rules.
+	// bus is currently used to publish event in case of title change
 	bus bus.Bus
 }
 
@@ -121,8 +121,12 @@ func (s *Service) Get(ctx context.Context, cmd *folder.GetFolderQuery) (*folder.
 		cmd.ID = nil
 		cmd.UID = &dashFolder.UID
 	}
-	f, err := s.store.Get(ctx, *cmd)
 
+	if dashFolder.IsGeneral() {
+		return dashFolder, nil
+	}
+
+	f, err := s.store.Get(ctx, *cmd)
 	if err != nil {
 		return nil, err
 	}
@@ -191,7 +195,7 @@ func (s *Service) GetParents(ctx context.Context, q folder.GetParentsQuery) ([]*
 
 func (s *Service) getFolderByID(ctx context.Context, user *user.SignedInUser, id int64, orgID int64) (*folder.Folder, error) {
 	if id == 0 {
-		return &folder.Folder{ID: id, Title: "General"}, nil
+		return &folder.GeneralFolder, nil
 	}
 
 	dashFolder, err := s.dashboardFolderStore.GetFolderByID(ctx, orgID, id)

pkg/services/folder/folderimpl/folder_test.go

@@ -763,6 +763,32 @@ func TestNestedFolderService(t *testing.T) {
 			assert.ErrorIs(t, err, folder.ErrMaximumDepthReached)
 			require.NotNil(t, actualCmd)
 		})
+
+		t.Run("get default folder, no error", func(t *testing.T) {
+			g := guardian.New
+			guardian.MockDashboardGuardian(&guardian.FakeDashboardGuardian{CanSaveValue: true})
+			t.Cleanup(func() {
+				guardian.New = g
+			})
+
+			// dashboard store commands that should be called.
+			dashStore := &dashboards.FakeDashboardStore{}
+
+			dashboardFolderStore := foldertest.NewFakeFolderStore(t)
+
+			nestedFolderStore := NewFakeStore()
+			nestedFolderStore.ExpectedError = folder.ErrFolderNotFound
+
+			folderSvc := setup(t, dashStore, dashboardFolderStore, nestedFolderStore, featuremgmt.WithFeatures("nestedFolders"), actest.FakeAccessControl{
+				ExpectedEvaluate: true,
+			})
+			_, err := folderSvc.Get(context.Background(), &folder.GetFolderQuery{
+				OrgID:        orgID,
+				ID:           &folder.GeneralFolder.ID,
+				SignedInUser: usr,
+			})
+			require.NoError(t, err)
+		})
 	})
 }
 

pkg/services/folder/model.go

@@ -42,6 +42,12 @@ type Folder struct {
 	HasACL    bool
 }
 
+var GeneralFolder = Folder{ID: 0, Title: "General"}
+
+func (f *Folder) IsGeneral() bool {
+	return f.ID == GeneralFolder.ID && f.Title == GeneralFolder.Title
+}
+
 type FolderDTO struct {
 	Folder