Test migration to jest by hand

Apparently using regular expressions is way easier.

test/xProd/xProd.test.js

@@ -0,0 +1,10 @@
+const expect = require('expect');
+const xProd = require('./xProd.js');
+
+
+  test('xProd is a Function', () => {
+  expect(xProd).toBeInstanceOf(Function);
+});
+  t.deepEqual(xProd([1, 2], ['a', 'b']), [[1, 'a'], [1, 'b'], [2, 'a'], [2, 'b']], `xProd([1, 2], ['a', 'b']) returns [[1, 'a'], [1, 'b'], [2, 'a'], [2, 'b']]`);
+  
+