const expect = require('expect'); const permutations = require('./permutations.js'); test('permutations is a Function', () => { expect(permutations).toBeInstanceOf(Function); }); test('Generates all permutations of an array', () => { expect(permutations([1, 33, 5])).toEqual([ [ 1, 33, 5 ], [ 1, 5, 33 ], [ 33, 1, 5 ], [ 33, 5, 1 ], [ 5, 1, 33 ], [ 5, 33, 1 ] ]); });