NestedFolders: Add API endpoint for descendant count in a folder (#66550)

* Add CountInFolder to RegistryService interface
* Add folder children counts api route
* Update fake GetFolderChildrenCounts
* Add test for getting folder children counts
* Add validation to folder children counts handler
* Update openapi specs
* Update pkg/services/folder/folderimpl/folder.go
Co-authored-by: Sofia Papagiannaki <1632407+papagian@users.noreply.github.com>

---------

Co-authored-by: Sofia Papagiannaki <1632407+papagian@users.noreply.github.com>

pkg/services/folder/folderimpl/folder.go

@@ -623,6 +623,28 @@ func (s *Service) nestedFolderDelete(ctx context.Context, cmd *folder.DeleteFold
 	return result, nil
 }
 
+func (s *Service) GetChildrenCounts(ctx context.Context, cmd *folder.GetChildrenCountsQuery) (folder.ChildrenCounts, error) {
+	if cmd.SignedInUser == nil {
+		return nil, folder.ErrBadRequest.Errorf("missing signed-in user")
+	}
+	if *cmd.UID == "" {
+		return nil, folder.ErrBadRequest.Errorf("missing UID")
+	}
+	if cmd.OrgID < 1 {
+		return nil, folder.ErrBadRequest.Errorf("invalid orgID")
+	}
+
+	countsMap := make(folder.ChildrenCounts, len(s.registry))
+	for _, v := range s.registry {
+		c, err := v.CountInFolder(ctx, cmd.OrgID, *cmd.UID, cmd.SignedInUser)
+		if err != nil {
+			return nil, err
+		}
+		countsMap[v.Kind()] += c
+	}
+	return countsMap, nil
+}
+
 // MakeUserAdmin is copy of DashboardServiceImpl.MakeUserAdmin
 func (s *Service) MakeUserAdmin(ctx context.Context, orgID int64, userID, folderID int64, setViewAndEditPermissions bool) error {
 	rtEditor := org.RoleEditor

pkg/services/folder/folderimpl/folder_test.go

@@ -12,6 +12,7 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"github.com/grafana/grafana/pkg/bus"
+	"github.com/grafana/grafana/pkg/infra/appcontext"
 	"github.com/grafana/grafana/pkg/infra/db"
 	"github.com/grafana/grafana/pkg/infra/db/dbtest"
 	"github.com/grafana/grafana/pkg/infra/log"
@@ -22,6 +23,7 @@ import (
 	acmock "github.com/grafana/grafana/pkg/services/accesscontrol/mock"
 	"github.com/grafana/grafana/pkg/services/dashboards"
 	"github.com/grafana/grafana/pkg/services/dashboards/database"
+	"github.com/grafana/grafana/pkg/services/dashboards/service"
 	"github.com/grafana/grafana/pkg/services/featuremgmt"
 	"github.com/grafana/grafana/pkg/services/folder"
 	"github.com/grafana/grafana/pkg/services/folder/foldertest"
@@ -930,6 +932,65 @@ func TestNestedFolderService(t *testing.T) {
 	})
 }
 
+func TestGetChildrenCounts(t *testing.T) {
+	g := guardian.New
+	guardian.MockDashboardGuardian(&guardian.FakeDashboardGuardian{CanViewValue: true})
+	t.Cleanup(func() {
+		guardian.New = g
+	})
+
+	folderId := rand.Int63()
+	folderUID := util.GenerateShortUID()
+	f := folder.NewFolder("Folder", "")
+	f.ID = folderId
+	f.UID = folderUID
+	f.OrgID = orgID
+
+	nestedFolderStore := NewFakeStore()
+	nestedFolderStore.ExpectedFolder = f
+
+	dashStore := dashboards.FakeDashboardStore{}
+	dashboardCount := int64(2)
+	countCmd := dashboards.CountDashboardsInFolderRequest{
+		FolderID: f.ID,
+		OrgID:    f.OrgID,
+	}
+	dashStore.On("CountDashboardsInFolder", mock.Anything, &countCmd).Return(dashboardCount, nil)
+
+	dashboardFolderStore := foldertest.NewFakeFolderStore(t)
+	dashboardFolderStore.On("GetFolderByUID", mock.Anything, orgID, folderUID).Return(f, nil)
+
+	cfg := setting.NewCfg()
+	cfg.RBACEnabled = false
+	features := featuremgmt.WithFeatures(featuremgmt.FlagNestedFolders)
+	folderService := &Service{
+		cfg:                  cfg,
+		store:                nestedFolderStore,
+		dashboardStore:       &dashStore,
+		dashboardFolderStore: dashboardFolderStore,
+		features:             features,
+		log:                  log.New("test-folder-service"),
+		accessControl:        acimpl.ProvideAccessControl(cfg),
+		registry:             make(map[string]folder.RegistryService),
+	}
+
+	ac := acmock.New()
+	folderPermissions := acmock.NewMockedPermissionsService()
+	dashboardPermissions := acmock.NewMockedPermissionsService()
+	_, err := service.ProvideDashboardServiceImpl(cfg, &dashStore, dashboardFolderStore, nil, features, folderPermissions, dashboardPermissions, ac, folderService)
+	require.NoError(t, err)
+
+	signedInUser := user.SignedInUser{UserID: 1, OrgID: orgID}
+	ctx := appcontext.WithUser(context.Background(), &signedInUser)
+	res, err := folderService.GetChildrenCounts(ctx, &folder.GetChildrenCountsQuery{
+		SignedInUser: usr,
+		UID:          &folderUID,
+		OrgID:        orgID,
+	})
+	require.NoError(t, err)
+	require.Equal(t, res["dashboard"], dashboardCount)
+}
+
 func CreateSubtreeInStore(t *testing.T, store *sqlStore, service *Service, depth int, prefix string, cmd folder.CreateFolderCommand) []string {
 	t.Helper()
 

pkg/services/folder/foldertest/foldertest.go

@@ -7,9 +7,10 @@ import (
 )
 
 type FakeService struct {
-	ExpectedFolders []*folder.Folder
-	ExpectedFolder  *folder.Folder
-	ExpectedError   error
+	ExpectedFolders        []*folder.Folder
+	ExpectedFolder         *folder.Folder
+	ExpectedError          error
+	ExpectedChildrenCounts map[string]int64
 }
 
 func NewFakeService() *FakeService {
@@ -49,3 +50,7 @@ func (s *FakeService) Move(ctx context.Context, cmd *folder.MoveFolderCommand) (
 func (s *FakeService) RegisterService(service folder.RegistryService) error {
 	return s.ExpectedError
 }
+
+func (s *FakeService) GetChildrenCounts(ctx context.Context, cmd *folder.GetChildrenCountsQuery) (folder.ChildrenCounts, error) {
+	return s.ExpectedChildrenCounts, s.ExpectedError
+}

pkg/services/folder/model.go

@@ -160,3 +160,14 @@ type HasEditPermissionInFoldersQuery struct {
 type HasAdminPermissionInDashboardsOrFoldersQuery struct {
 	SignedInUser *user.SignedInUser
 }
+
+// GetChildrenCountsQuery captures the information required by the folder service
+// to return the count of children in a folder.
+type GetChildrenCountsQuery struct {
+	UID   *string
+	OrgID int64
+
+	SignedInUser *user.SignedInUser `json:"-"`
+}
+
+type ChildrenCounts map[string]int64

pkg/services/folder/registry.go

@@ -2,9 +2,12 @@ package folder
 
 import (
 	"context"
+
+	"github.com/grafana/grafana/pkg/services/user"
 )
 
 type RegistryService interface {
-	DeleteInFolder(ctx context.Context, orgID int64, UID string) error
+	DeleteInFolder(ctx context.Context, orgID int64, uid string) error
+	CountInFolder(ctx context.Context, orgID int64, uid string, user *user.SignedInUser) (int64, error)
 	Kind() string
 }

pkg/services/folder/service.go

@@ -26,6 +26,7 @@ type Service interface {
 	// Move changes a folder's parent folder to the requested new parent.
 	Move(ctx context.Context, cmd *MoveFolderCommand) (*Folder, error)
 	RegisterService(service RegistryService) error
+	GetChildrenCounts(ctx context.Context, cmd *GetChildrenCountsQuery) (ChildrenCounts, error)
 }
 
 // FolderStore is a folder store.