Additional tests and updated hide footprint to match show

test/show.test.js

@@ -4,3 +4,9 @@ const {show} = require('./_30s.js');
 test('show is a Function', () => {
   expect(show).toBeInstanceOf(Function);
 });
+test('show shows an element', () => {
+  let el = document.createElement('div');
+  el.setAttribute('style', 'display: none;');
+  show(el);
+  expect(el.style.display).not.toBe('none');
+});