remove test folder and add jest test setup

Author: rwieruch

jest.config.json

@@ -0,0 +1,6 @@
+{
+  "testRegex": "((\\.|/*.)(spec))\\.js?$",
+  "setupFilesAfterEnv": [
+    "<rootDir>/jest.setup.js"
+  ]
+}

jest.setup.js

@@ -0,0 +1,6 @@
+import React from 'react';
+
+import { configure } from 'enzyme';
+import Adapter from 'enzyme-adapter-react-16';
+
+configure({ adapter: new Adapter() });

package.json

@@ -5,7 +5,7 @@
   "main": "index.js",
   "scripts": {
     "start": "webpack-dev-server --config ./webpack.config.js --mode development",
-    "test": "jest --config ./test/jest.config.json",
+    "test": "jest --config ./jest.config.json",
     "test:watch": "npm run test -- --watch",
     "test:cypress": "start-server-and-test start http://localhost:8080 cypress",
     "cypress": "cypress run",

src/App.spec.js

@@ -1,10 +1,7 @@
 import React from 'react';
 import axios from 'axios';
 import renderer from 'react-test-renderer';
-import { mount, configure } from 'enzyme';
-import Adapter from 'enzyme-adapter-react-16';
-
-configure({ adapter: new Adapter() });
+import { mount } from 'enzyme';
 
 import App, { dataReducer, Counter } from './App';