Test migration to jest by hand

Apparently using regular expressions is way easier.

test/shuffle/shuffle.js

@@ -0,0 +1,9 @@
+const shuffle = ([...arr]) => {
+let m = arr.length;
+while (m) {
+const i = Math.floor(Math.random() * m--);
+[arr[m], arr[i]] = [arr[i], arr[m]];
+}
+return arr;
+};
+module.exports = shuffle;

test/shuffle/shuffle.test.js

@@ -0,0 +1,16 @@
+const expect = require('expect');
+const shuffle = require('./shuffle.js');
+
+
+  test('shuffle is a Function', () => {
+  expect(shuffle).toBeInstanceOf(Function);
+});
+  const arr = [1,2,3,4,5,6];
+  t.notEqual(shuffle(arr), arr, 'Shuffles the array');
+  test('New array contains all original elements', () => {
+  expect(shuffle(arr).every(x => arr.includes(x))).toBeTruthy();
+});
+  t.deepEqual(shuffle([]),[],'Works for empty arrays');
+  t.deepEqual(shuffle([1]),[1],'Works for single-element arrays');
+  
+