Test migration to jest by hand

Apparently using regular expressions is way easier.

test/sampleSize/sampleSize.js

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

test/sampleSize/sampleSize.test.js

@@ -0,0 +1,17 @@
+const expect = require('expect');
+const sampleSize = require('./sampleSize.js');
+
+
+  test('sampleSize is a Function', () => {
+  expect(sampleSize).toBeInstanceOf(Function);
+});
+  const arr = [3,7,9,11];
+  t.equal(sampleSize(arr).length, 1, 'Returns a single element without n specified');
+  test('Returns a random sample of specified size from an array', () => {
+  expect(sampleSize(arr, 2).every(x => arr.includes(x))).toBeTruthy();
+});
+  t.equal(sampleSize(arr, 5).length, 4, 'Returns all elements in an array if n >= length');
+  t.deepEqual(sampleSize([], 2), [], 'Returns an empty array if original array is empty');
+  t.deepEqual(sampleSize(arr, 0), [], 'Returns an empty array if n = 0');
+  
+