Test migration to jest by hand

Apparently using regular expressions is way easier.

test/randomIntArrayInRange/randomIntArrayInRange.test.js

@@ -0,0 +1,19 @@
+const expect = require('expect');
+const randomIntArrayInRange = require('./randomIntArrayInRange.js');
+
+
+  test('randomIntArrayInRange is a Function', () => {
+  expect(randomIntArrayInRange).toBeInstanceOf(Function);
+});
+  const lowerLimit = Math.floor(Math.random() * 20);
+  const upperLimit = Math.floor(lowerLimit + Math.random() * 10);
+  const arr = randomIntArrayInRange(lowerLimit,upperLimit, 10);
+  test('The returned array contains only integers', () => {
+  expect(arr.every(x => typeof x === 'number')).toBeTruthy();
+});
+  t.equal(arr.length, 10, 'The returned array has the proper length');
+  test('The returned array\'s values lie between provided lowerLimit and upperLimit (both inclusive).', () => {
+  expect(arr.every(x => (x >= lowerLimit) && (x <= upperLimit))).toBeTruthy();
+});
+  
+