add simple test to reproduce groupBy regression

giggo1604 · giggo1604 · commit 02880de7eed9 · 2025-04-29T09:59:47.000+02:00
diff --git a/__tests__/regression.ts b/__tests__/regression.ts
@@ -0,0 +1,9 @@
+import { describe, expect, it } from '@jest/globals';
+import { List } from 'immutable';
+
+describe('undefined groupBy', () => {
+  it('should not throw an error when groupBy is called with undefined', () => {
+    const list = List([1, 2, 3]);
+    expect(() => list.groupBy(() => undefined)).not.toThrow();
+  });
+});
