Updated the test system

test/toKebabCase.test.js

@@ -0,0 +1,48 @@
+const expect = require('expect');
+const {toKebabCase} = require('./_30s.js');
+
+test('toKebabCase is a Function', () => {
+  expect(toKebabCase).toBeInstanceOf(Function);
+});
+test("toKebabCase('camelCase') returns camel-case", () => {
+  expect(toKebabCase('camelCase')).toBe('camel-case');
+});
+test("toKebabCase('some text') returns some-text", () => {
+  expect(toKebabCase('some text')).toBe('some-text');
+});
+test("toKebabCase('some-mixed-string With spaces-underscores-and-hyphens') returns some-mixed-string-with-spaces-underscores-and-hyphens", () => {
+  expect(toKebabCase('some-mixed-string With spaces-underscores-and-hyphens')).toBe(
+    'some-mixed-string-with-spaces-underscores-and-hyphens'
+  );
+});
+test("toKebabCase('IAmListeningToFMWhileLoadingDifferentURLOnMyBrowserAndAlsoEditingSomeXMLAndHTML') returns i-am-listening-to-fm-while-loading-different-url-on-my-browser-and-also-editing-some-xml-and-html", () => {
+  expect(
+    toKebabCase('IAmListeningToFMWhileLoadingDifferentURLOnMyBrowserAndAlsoEditingSomeXMLAndHTML')
+  ).toBe(
+    'i-am-listening-to-fm-while-loading-different-url-on-my-browser-and-also-editing-some-xml-and-html'
+  );
+});
+test('toKebabCase() returns undefined', () => {
+  expect(toKebabCase()).toBe(undefined);
+});
+test('toKebabCase([]) throws an erro', () => {
+  expect(() => {
+    toKebabCase([]);
+  }).toThrow();
+});
+test('toKebabCase({}) throws an erro', () => {
+  expect(() => {
+    toKebabCase({});
+  }).toThrow();
+});
+test('toKebabCase(123) throws an erro', () => {
+  expect(() => {
+    toKebabCase(123);
+  }).toThrow();
+});
+let start = new Date().getTime();
+toKebabCase('IAmListeningToFMWhileLoadingDifferentURLOnMyBrowserAndAlsoEditingSomeXMLAndHTML');
+let end = new Date().getTime();
+test('toKebabCase(IAmListeningToFMWhileLoadingDifferentURLOnMyBrowserAndAlsoEditingSomeXMLAndHTML) takes less than 2s to run', () => {
+  expect(end - start < 2000).toBeTruthy();
+});