feat(table-core): fix API to calculate max expanded row depth

examples/react/basic/src/data.ts

@@ -0,0 +1,44 @@
+export type Person = {
+  firstName: string;
+  lastName: string;
+  age: number;
+  visits: number;
+  subRows?: Person[]; // <-- Key to nesting!
+};
+
+export const defaultData: Person[] = [
+  {
+    firstName: 'Tanner',
+    lastName: 'Linsley',
+    age: 24,
+    visits: 100,
+    subRows: [ // These are the nested rows for Tanner
+      {
+        firstName: 'Kevin',
+        lastName: 'Vandy',
+        age: 27,
+        visits: 200,
+      },
+      {
+        firstName: 'John',
+        lastName: 'Doe',
+        age: 45,
+        visits: 20,
+        subRows: [ // Deeper nesting is possible
+          {
+            firstName: 'Child',
+            lastName: 'Doe',
+            age: 5,
+            visits: 1,
+          },
+        ],
+      },
+    ],
+  },
+  {
+    firstName: 'Jane',
+    lastName: 'Doe',
+    age: 40,
+    visits: 80,
+  },
+];

packages/table-core/src/features/RowExpanding.ts

@@ -311,8 +311,15 @@ export const RowExpanding: TableFeature = {
         }
 
         if (exists && !expanded) {
-          const { [row.id]: _, ...rest } = oldExpanded
-          return rest
+          const currentExpandedState = table.getState().expanded as ExpandedStateList;
+          const rowIds = Object.keys(currentExpandedState);
+          const updatedExpandedState = rowIds.reduce((acc, rowId) => {
+            if (!rowId.startsWith(row.id)) {
+              acc[rowId] = !!(currentExpandedState[rowId]);
+            }
+            return acc;
+          }, {} as ExpandedStateList);
+          return updatedExpandedState;
         }
 
         return old