Fix broken context menu in dataset-view-mode when no segmentation lay…

…er is visible (#6259)

* fix broken context menu in dataset-view-mode when no segmentation layer is visible

* update changelog

CHANGELOG.unreleased.md

@@ -18,6 +18,7 @@ Added a warning for when the resolution in the XY viewport on z=1-downsampled da
 
 
 ### Fixed
+- Fixed that the context menu broke webKnossos when opening it in dataset-view-mode while no segmentation layer was visible. [#6259](https://github.com/scalableminds/webknossos/pull/6259)
 
 ### Removed
 

frontend/javascripts/oxalis/view/context_menu.tsx

@@ -350,11 +350,13 @@ function NodeContextMenuOptions({
   volumeTracing,
   infoRows,
   allowUpdate,
-}: NodeContextMenuOptionsProps) {
+}: NodeContextMenuOptionsProps): JSX.Element {
   const dispatch = useDispatch();
 
   if (skeletonTracing == null) {
-    return null;
+    throw new Error(
+      "NodeContextMenuOptions should not have been called without existing skeleton tracing.",
+    );
   }
 
   const { userBoundingBoxes } = skeletonTracing;
@@ -613,7 +615,7 @@ function getBoundingBoxMenuOptions({
   ];
 }
 
-function NoNodeContextMenuOptions(props: NoNodeContextMenuProps) {
+function NoNodeContextMenuOptions(props: NoNodeContextMenuProps): JSX.Element {
   const {
     skeletonTracing,
     volumeTracing,
@@ -799,10 +801,6 @@ function NoNodeContextMenuOptions(props: NoNodeContextMenuProps) {
     allActions = nonSkeletonActions.concat(skeletonActions).concat(boundingBoxActions);
   }
 
-  if (allActions.length === 0) {
-    return null;
-  }
-
   return (
     <Menu
       onClick={hideContextMenu}
@@ -888,7 +886,6 @@ function ContextMenuInner(propsWithInputRef: PropsWithRef) {
   const { inputRef, ...props } = propsWithInputRef;
   const {
     skeletonTracing,
-    activeTool,
     maybeClickedNodeId,
     contextMenuPosition,
     hideContextMenu,
@@ -1000,7 +997,6 @@ function ContextMenuInner(propsWithInputRef: PropsWithRef) {
     // for the following two expressions, since this breaks
     // antd's internal population of the correct class names
     // for the menu.
-    // @ts-expect-error ts-migrate(2322) FIXME: Type 'Element | null' is not assignable to type 'E... Remove this comment to see the full error message
     overlay =
       maybeClickedNodeId != null
         ? NodeContextMenuOptions({
@@ -1010,8 +1006,6 @@ function ContextMenuInner(propsWithInputRef: PropsWithRef) {
             ...props,
           })
         : NoNodeContextMenuOptions({
-            // @ts-expect-error ts-migrate(2783) FIXME: 'activeTool' is specified more than once, so this ... Remove this comment to see the full error message
-            activeTool,
             segmentIdAtPosition,
             infoRows,
             viewport: maybeViewport,