test(json-crdt-extensions): 💍 add test for cursor in same position as marker

Author: streamich

src/json-crdt-extensions/peritext/overlay/Overlay.ts

@@ -315,11 +315,9 @@ export class Overlay<T = string> implements Printable, Stateful {
    * @returns Whether the point is a marker point.
    */
   public isMarker(id: ITimestampStruct): boolean {
-    const point = this.txt.point(id, Anchor.Before);
-    const overlayPoint = this.getOrNextLower(point);
-    return (
-      overlayPoint instanceof MarkerOverlayPoint && overlayPoint.id.time === id.time && overlayPoint.id.sid === id.sid
-    );
+    const p = this.txt.point(id, Anchor.Before);
+    const op = this.getOrNextLower(p);
+    return op instanceof MarkerOverlayPoint && op.id.time === id.time && op.id.sid === id.sid;
   }
 
   // ----------------------------------------------------------------- Stateful
@@ -405,7 +403,6 @@ export class Overlay<T = string> implements Printable, Stateful {
   }
 
   private insMarker(slice: MarkerSlice<T>): [start: OverlayPoint<T>, end: OverlayPoint<T>] {
-    // TODO: When marker is at rel start, and cursor too, the overlay point should have reference to the cursor.
     const point = this.mPoint(slice, Anchor.Before);
     const pivot = this.insPoint(point);
     if (!pivot) {

src/json-crdt-extensions/peritext/overlay/__tests__/Overlay.spec.ts

@@ -65,6 +65,18 @@ describe('markers', () => {
       peritext.overlay.refresh();
       expect(markerCount(peritext)).toBe(2);
     });
+
+    test('does reference cursor, when marker and cursor are at the same position', () => {
+      const {peritext} = setup();
+      peritext.editor.cursor.setAt(3);
+      const [marker] = peritext.editor.saved.insMarker(['p'], '¶');
+      peritext.editor.cursor.set(marker.start.clone());
+      peritext.overlay.refresh();
+      const overlayMarkerPoint = peritext.overlay.root2!;
+      expect(overlayMarkerPoint instanceof MarkerOverlayPoint).toBe(true);
+      expect(overlayMarkerPoint.markers.length).toBe(1);
+      expect(overlayMarkerPoint.markers.find((m) => m === peritext.editor.cursor)).toBe(peritext.editor.cursor);
+    });
   });
 
   describe('deletes', () => {