Enhance isSomeSelected logic and add related test cases

- Updated `isSomeSelected` to check if selected items exist in the current data.
- Added tests to verify `isSomeSelected` returns correct values for various selection states.

Author: Han5991

packages/@mantine/hooks/src/use-selection/use-selection.test.ts

@@ -105,6 +105,27 @@ describe('@mantine/hooks/use-selection', () => {
     expect(result2.current[1].isSomeSelected()).toBe(false);
   });
 
+  it('isSomeSelected returns false when selected items are not in current data', () => {
+    const { result } = renderHook(() => useSelection([1, 2, 3]));
+
+    act(() => {
+      result.current[1].setSelection([4, 5]);
+    });
+
+    expect(result.current[1].isSomeSelected()).toBe(false);
+  });
+
+  it('isSomeSelected returns true when some selected items exist in data', () => {
+    const { result } = renderHook(() => useSelection([1, 2, 3]));
+
+    // Set selection with mix of existing and non-existing items
+    act(() => {
+      result.current[1].setSelection([1, 4, 5]);
+    });
+
+    expect(result.current[1].isSomeSelected()).toBe(true);
+  });
+
   it('checks if some items are selected', () => {
     const { result } = renderHook(() => useSelection(initialData));
     // Initially, no items are selected

packages/@mantine/hooks/src/use-selection/use-selection.ts

@@ -48,12 +48,13 @@ export function useSelection<T>(data: T[], initialSelection?: T[]): [T[], Select
   }, []);
 
   const isAllSelected = useCallback(
-    () => data.length > 0 && data.every((item) => selected.has(item)),
+    () => data.length > 0 && data.every(item => selected.has(item)),
     [data, selected]
   );
 
   const isSomeSelected = useCallback(
-    () => data.length > 0 && selected.size > 0 && !isAllSelected(),
+    () => data.length > 0 && selected.size > 0 &&
+      data.some(item => selected.has(item)) && !isAllSelected(),
     [data, selected, isAllSelected]
   );