Test migration to jest by hand

Apparently using regular expressions is way easier.

test/isNumber/isNumber.js

@@ -0,0 +1,2 @@
+const isNumber = val => typeof val === 'number';
+module.exports = isNumber;

test/isNumber/isNumber.test.js

@@ -0,0 +1,10 @@
+const expect = require('expect');
+const isNumber = require('./isNumber.js');
+
+
+  test('isNumber is a Function', () => {
+  expect(isNumber).toBeInstanceOf(Function);
+});
+  t.equal(isNumber(1), true, "passed argument is a number");
+  t.equal(isNumber('1'), false, "passed argument is not a number");
+