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

pkg/api/apierrors/folder.go

@@ -3,6 +3,7 @@ package apierrors
 import (
 	"encoding/json"
 	"errors"
+	"fmt"
 	"net/http"
 
 	k8sErrors "k8s.io/apimachinery/pkg/api/errors"
@@ -17,45 +18,49 @@ import (
 
 // ToFolderErrorResponse returns a different response status according to the folder error type
 func ToFolderErrorResponse(err error) response.Response {
+	// --- Dashboard errors ---
 	var dashboardErr dashboardaccess.DashboardErr
 	if ok := errors.As(err, &dashboardErr); ok {
 		return response.Error(dashboardErr.StatusCode, err.Error(), err)
 	}
 
+	// --- 400 Bad Request ---
 	if errors.Is(err, dashboards.ErrFolderTitleEmpty) ||
 		errors.Is(err, dashboards.ErrDashboardTypeMismatch) ||
 		errors.Is(err, dashboards.ErrDashboardInvalidUid) ||
-		errors.Is(err, dashboards.ErrDashboardUidTooLong) {
+		errors.Is(err, dashboards.ErrDashboardUidTooLong) ||
+		errors.Is(err, folder.ErrFolderCannotBeParentOfItself) {
 		return response.Error(http.StatusBadRequest, err.Error(), nil)
 	}
 
+	// --- 403 Forbidden ---
 	if errors.Is(err, dashboards.ErrFolderAccessDenied) {
 		return response.Error(http.StatusForbidden, "Access denied", err)
 	}
 
+	// --- 404 Not Found ---
 	if errors.Is(err, dashboards.ErrFolderNotFound) {
 		return response.JSON(http.StatusNotFound, util.DynMap{"status": "not-found", "message": dashboards.ErrFolderNotFound.Error()})
 	}
 
+	// --- 409 Conflict ---
 	if errors.Is(err, dashboards.ErrFolderWithSameUIDExists) {
 		return response.Error(http.StatusConflict, err.Error(), nil)
 	}
 
+	// --- 412 Precondition Failed ---
 	if errors.Is(err, dashboards.ErrFolderVersionMismatch) ||
 		k8sErrors.IsAlreadyExists(err) {
 		return response.JSON(http.StatusPreconditionFailed, util.DynMap{"status": "version-mismatch", "message": dashboards.ErrFolderVersionMismatch.Error()})
 	}
 
-	if errors.Is(err, folder.ErrMaximumDepthReached) {
-		return response.JSON(http.StatusBadRequest, util.DynMap{"messageId": "folder.maximum-depth-reached", "message": folder.ErrMaximumDepthReached.Error()})
-	}
-
+	// --- Kubernetes status errors ---
 	var statusErr *k8sErrors.StatusError
 	if errors.As(err, &statusErr) {
 		return response.Error(int(statusErr.ErrStatus.Code), statusErr.ErrStatus.Message, err)
 	}
 
-	return response.ErrOrFallback(http.StatusInternalServerError, "Folder API error", err)
+	return response.ErrOrFallback(http.StatusInternalServerError, fmt.Sprintf("Folder API error: %s", err.Error()), err)
 }
 
 func ToFolderStatusError(err error) k8sErrors.StatusError {