Updated the test system

test/isObject.test.js

@@ -0,0 +1,18 @@
+const expect = require('expect');
+const {isObject} = require('./_30s.js');
+
+test('isObject is a Function', () => {
+  expect(isObject).toBeInstanceOf(Function);
+});
+test('isObject([1, 2, 3, 4]) is a object', () => {
+  expect(isObject([1, 2, 3, 4])).toBeTruthy();
+});
+test('isObject([]) is a object', () => {
+  expect(isObject([])).toBeTruthy();
+});
+test('isObject({ a:1 }) is a object', () => {
+  expect(isObject({ a: 1 })).toBeTruthy();
+});
+test('isObject(true) is not a object', () => {
+  expect(isObject(true)).toBeFalsy();
+});