test(graph): root children permission denied is 404

GetRootDriveChildren and GetDriveItem fill
@libre.graph.permissions.actions.allowedValues on $select, the shared
children listing did not, so every child in /children and $expand=children
came back without its allowed actions and clients treated the listing as read
only. Add a setDriveItem(s)AllowedValues helper pair, matching the thumbnails
and shareTypes shape, and apply it in the listing.

GetRootDriveChildren now delegates to the shared children listing instead of
repeating its ListContainer + format + shareTypes tail; permission denied on
the root listing answers 404 like the item children endpoint (the TODO that
sat there), not 403.

services/graph/pkg/service/v0/driveitems.go

@@ -222,50 +222,9 @@ func (g Graph) GetRootDriveChildren(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	listRequest := &storageprovider.ListContainerRequest{
-		Ref: &storageprovider.Reference{ResourceId: space.GetRoot()},
-	}
-	if driveItemPropertySelected(r, _selectShareTypes) {
-		listRequest.FieldMask = shareTypesFieldMask
-	}
-
-	lRes, err := gatewayClient.ListContainer(ctx, listRequest)
-	switch {
-	case err != nil:
-		g.logger.Error().Err(err).Msg("error making ListContainer grpc call")
-		errorcode.ServiceNotAvailable.Render(w, r, http.StatusInternalServerError, err.Error())
+	files, ok := g.listDriveItemChildren(w, r, space.GetRoot())
+	if !ok {
 		return
-	case lRes.GetStatus().GetCode() != cs3rpc.Code_CODE_OK:
-		if lRes.GetStatus().GetCode() == cs3rpc.Code_CODE_NOT_FOUND {
-			errorcode.ItemNotFound.Render(w, r, http.StatusNotFound, lRes.GetStatus().GetMessage())
-			return
-		}
-		if lRes.GetStatus().GetCode() == cs3rpc.Code_CODE_PERMISSION_DENIED {
-			// TODO check if we should return 404 to not disclose existing items
-			errorcode.AccessDenied.Render(w, r, http.StatusForbidden, lRes.GetStatus().GetMessage())
-			return
-		}
-		g.logger.Error().Err(err).Msg("error sending list container grpc request")
-		errorcode.GeneralException.Render(w, r, http.StatusInternalServerError, res.GetStatus().GetMessage())
-		return
-	}
-
-	files, err := formatDriveItems(g.logger, g.publicBaseURL, lRes.GetInfos())
-	if err != nil {
-		g.logger.Error().Err(err).Msg("error encoding response as json")
-		errorcode.GeneralException.Render(w, r, http.StatusInternalServerError, err.Error())
-		return
-	}
-	g.setDriveItemsThumbnails(r, files, lRes.GetInfos())
-
-	if driveItemPropertySelected(r, _selectAllowedValues) {
-		for i, info := range lRes.GetInfos() {
-			files[i].LibreGraphPermissionsActionsAllowedValues = unifiedrole.CS3ResourcePermissionsToLibregraphActions(info.GetPermissionSet())
-		}
-	}
-
-	if driveItemPropertySelected(r, _selectShareTypes) {
-		g.addShareTypes(ctx, files, lRes.GetInfos())
 	}
 
 	render.Status(r, http.StatusOK)
@@ -333,7 +292,7 @@ func (g Graph) GetDriveItem(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if driveItemPropertySelected(r, _selectAllowedValues) {
-		driveItem.LibreGraphPermissionsActionsAllowedValues = unifiedrole.CS3ResourcePermissionsToLibregraphActions(res.GetInfo().GetPermissionSet())
+		setDriveItemAllowedValues(driveItem, res.GetInfo())
 	}
 
 	// only containers have children
@@ -436,6 +395,8 @@ func (g Graph) listDriveItemChildren(w http.ResponseWriter, r *http.Request, dri
 		return nil, false
 	}
 
+	setDriveItemsAllowedValues(r, files, res.GetInfos())
+
 	if driveItemPropertySelected(r, _selectShareTypes) {
 		g.addShareTypes(r.Context(), files, res.GetInfos())
 	}
@@ -445,6 +406,25 @@ func (g Graph) listDriveItemChildren(w http.ResponseWriter, r *http.Request, dri
 	return files, true
 }
 
+// setDriveItemAllowedValues fills @libre.graph.permissions.actions.allowedValues
+// from the item's permission set.
+func setDriveItemAllowedValues(item *libregraph.DriveItem, info *storageprovider.ResourceInfo) {
+	item.LibreGraphPermissionsActionsAllowedValues = unifiedrole.CS3ResourcePermissionsToLibregraphActions(info.GetPermissionSet())
+}
+
+// setDriveItemsAllowedValues does the same across a listing, when the property
+// was selected.
+func setDriveItemsAllowedValues(r *http.Request, items []libregraph.DriveItem, infos []*storageprovider.ResourceInfo) {
+	if !driveItemPropertySelected(r, _selectAllowedValues) {
+		return
+	}
+	for i := range items {
+		if i < len(infos) {
+			setDriveItemAllowedValues(&items[i], infos[i])
+		}
+	}
+}
+
 func (g Graph) getRemoteItem(ctx context.Context, root *storageprovider.ResourceId, baseURL *url.URL) (*libregraph.RemoteItem, error) {
 	gatewayClient, err := g.gatewaySelector.Next()
 	if err != nil {

services/graph/pkg/service/v0/driveitems_test.go

@@ -142,7 +142,7 @@ var _ = Describe("Driveitems", func() {
 			Expect(rr.Code).To(Equal(http.StatusNotFound))
 		})
 
-		It("handles ListContainer permission denied", func() {
+		It("handles ListContainer permission denied as not found", func() {
 			gatewayClient.On("ListStorageSpaces", mock.Anything, mock.Anything).Return(&provider.ListStorageSpacesResponse{
 				Status:        status.NewOK(ctx),
 				StorageSpaces: []*provider.StorageSpace{{Owner: currentUser, Root: &provider.ResourceId{}}},
@@ -154,7 +154,7 @@ var _ = Describe("Driveitems", func() {
 			r := httptest.NewRequest(http.MethodGet, "/graph/v1.0/me/drive/root/children", nil)
 			r = r.WithContext(revactx.ContextSetUser(ctx, currentUser))
 			svc.GetRootDriveChildren(rr, r)
-			Expect(rr.Code).To(Equal(http.StatusForbidden))
+			Expect(rr.Code).To(Equal(http.StatusNotFound))
 		})
 
 		It("handles ListContainer error", func() {
@@ -515,6 +515,35 @@ var _ = Describe("Driveitems", func() {
 				Expect(res.Value[0].PendingOperations).To(BeNil())
 			})
 
+			It("returns the allowed actions when selected", func() {
+				r = r.WithContext(r.Context())
+				q := r.URL.Query()
+				q.Add("$select", "@libre.graph.permissions.actions.allowedValues")
+				r.URL.RawQuery = q.Encode()
+
+				gatewayClient.On("ListContainer", mock.Anything, mock.Anything).Return(&provider.ListContainerResponse{
+					Status: status.NewOK(ctx),
+					Infos: []*provider.ResourceInfo{
+						{
+							Type:  provider.ResourceType_RESOURCE_TYPE_FILE,
+							Id:    &provider.ResourceId{StorageId: "storageid", SpaceId: "spaceid", OpaqueId: "opaqueid"},
+							Etag:  "etag",
+							Mtime: utils.TimeToTS(mtime),
+							PermissionSet: &provider.ResourcePermissions{
+								GetPath:              true,
+								InitiateFileDownload: true,
+							},
+						},
+					},
+				}, nil)
+
+				res := assertItemsList(1)
+				Expect(res.Value[0].GetLibreGraphPermissionsActionsAllowedValues()).To(ConsistOf(
+					unifiedrole.DriveItemPathRead,
+					unifiedrole.DriveItemContentRead,
+				))
+			})
+
 			It("omits share types unless they are selected", func() {
 				gatewayClient.On("ListContainer", mock.Anything, mock.Anything).Return(&provider.ListContainerResponse{
 					Status: status.NewOK(ctx),