Test migration to jest by hand

Apparently using regular expressions is way easier.

test/promisify/promisify.test.js

@@ -0,0 +1,15 @@
+const expect = require('expect');
+const promisify = require('./promisify.js');
+
+
+  test('promisify is a Function', () => {
+  expect(promisify).toBeInstanceOf(Function);
+});
+  const x = promisify(Math.max);
+  test('Returns a promise', () => {
+  expect(x() instanceof Promise).toBeTruthy();
+});
+  const delay = promisify((d, cb) => setTimeout(cb, d));
+  delay(200).then(() => t.pass('Runs the function provided'));
+  
+