import { createNullMovingComparator } from './createNullMovingComparator'; describe('createNullMovingComparator', () => { it('Moves nulls left', () => { const input = [null, 3, null, 2, null, 1, null]; const comparator = createNullMovingComparator('left'); expect([...input].sort(comparator)).toEqual([null, null, null, null, 3, 2, 1]); }); it('Moves nulls right', () => { const input = [null, 3, null, 2, null, 1, null]; const comparator = createNullMovingComparator('right'); expect([...input].sort(comparator)).toEqual([3, 2, 1, null, null, null, null]); }); });