const expect = require('expect'); const {uniqueSymmetricDifference} = require('./_30s.js'); test('uniqueSymmetricDifference is a Function', () => { expect(uniqueSymmetricDifference).toBeInstanceOf(Function); }); test('Returns the symmetric difference between two arrays.', () => { expect(uniqueSymmetricDifference([1, 2, 3], [1, 2, 4])).toEqual([3, 4]); }); test('Does not return duplicates from one array', () => { expect(uniqueSymmetricDifference([1, 2, 2], [1, 3, 1])).toEqual([2, 3]); });