Support right-side gutter in collapseUnchangedGutter extension

Author: VasylMarchuk

app/utils/code-mirror-collapse-unchanged-gutter.ts

@@ -1,4 +1,5 @@
 import { EditorView, gutter, GutterMarker, type WidgetType } from '@codemirror/view';
+import { gutter as gutterRS, GutterMarker as GutterMarkerRS } from 'codecrafters-frontend/utils/code-mirror-gutter-rs';
 
 function isCollapseUnchangedWidget(widget: WidgetType) {
   return 'type' in widget && widget.type === 'collapsed-unchanged-code';
@@ -34,6 +35,11 @@ export class CollapseUnchangedGutterMarker extends GutterMarker {
   toDOM = toDOM;
 }
 
+export class CollapseUnchangedGutterMarkerRS extends GutterMarkerRS {
+  elementClass = 'cm-collapseUnchangedBarSibling';
+  toDOM = toDOM;
+}
+
 export function collapseUnchangedGutter() {
   return [
     gutter({
@@ -43,5 +49,12 @@ export function collapseUnchangedGutter() {
         return isCollapseUnchangedWidget(widget) ? new CollapseUnchangedGutterMarker() : null;
       },
     }),
+    gutterRS({
+      class: 'cm-collapseUnchangedGutter',
+      renderEmptyElements: true,
+      widgetMarker(_view, widget, _block) {
+        return isCollapseUnchangedWidget(widget) ? new CollapseUnchangedGutterMarkerRS() : null;
+      },
+    }),
   ];
 }