Add GoodBye testing

Author: xJkit

__tests__/GoodBye.spec.js

@@ -0,0 +1,22 @@
+import React from 'react';
+import { shallow, mount } from 'enzyme';
+
+import GoodBye from '../src';
+
+describe('GoodBye', () => {
+  test('should handleBeforeUnload handle function works expectedly', () => {
+    const childFunction = jest.fn();
+    const fakeMsg = "hello, world.";
+    const evt = {};
+    const wrapper = shallow(
+      <GoodBye
+        when
+        alertBeforeUnload
+        alertMessage={fakeMsg}
+        children={childFunction}
+      />
+    );
+    expect(wrapper.instance().handleBeforeUnload(evt)).toBe(fakeMsg);
+    expect(evt.returnValue).toBe(fakeMsg);
+  });
+})

__tests__/provider.spec.js

@@ -1,6 +1,6 @@
 import React from 'react';
 import { shallow } from 'enzyme';
-import GoodBye, { Provider, withGoodBye } from '../src';
+import { Provider } from '../src';
 
 describe('<Provider />', () => {
   test('should receive handleGetUserConfirm render prop', () => {