Upgrade jest and simplify .babelrc (#1913)

* Upgrade jest and simplify .babelrc

* Fix linter

examples/with-jest/.babelrc

@@ -1,15 +1,16 @@
 {
   "env": {
     "development": {
-      "presets": ["next/babel"]
+      "presets": "next/babel"
     },
     "production": {
-      "presets": ["next/babel"]
+      "presets": "next/babel"
     },
     "test": {
-      // next/babel does not transpile import/export syntax.
-      // So, using es2015 in the beginning will fix that.
-      "presets": ["es2015", "next/babel"]
+      "presets": [
+        ["env", { "modules": "commonjs" }],
+        "next/babel"
+      ]
     }
   }
 }

examples/with-jest/__tests__/__snapshots__/index.test.js.snap

@@ -1,8 +1,12 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
 exports[`With Snapshot Testing App shows "Hello world!" 1`] = `
 <div
-  data-jsx={2648947580}>
+  data-jsx={2648947580}
+>
   <p
-    data-jsx={2648947580}>
+    data-jsx={2648947580}
+  >
     Hello World!
   </p>
 </div>

examples/with-jest/__tests__/index.test.js

@@ -1,15 +1,14 @@
-/* global it, expect, describe */
+/* eslint-env jest */
 
-import React from 'react'
 import { shallow } from 'enzyme'
+import React from 'react'
 import renderer from 'react-test-renderer'
+
 import App from '../pages/index.js'
 
 describe('With Enzyme', () => {
   it('App shows "Hello world!"', () => {
-    const app = shallow(
-      <App />
-    )
+    const app = shallow(<App />)
 
     expect(app.find('p').text()).toEqual('Hello World!')
   })

examples/with-jest/package.json

@@ -2,20 +2,19 @@
   "name": "with-jest",
   "dependencies": {
     "next": "latest",
-    "react": "^15.4.2",
-    "react-dom": "^15.4.2"
+    "react": "^15.5.4",
+    "react-dom": "^15.5.4"
+  },
+  "devDependencies": {
+    "enzyme": "^2.8.2",
+    "jest": "^20.0.0",
+    "react-addons-test-utils": "^15.5.1",
+    "react-test-renderer": "^15.5.4"
   },
   "scripts": {
     "test": "jest",
     "dev": "next",
     "build": "next build",
     "start": "next start"
-  },
-  "devDependencies": {
-    "enzyme": "^2.5.1",
-    "jest-cli": "^18.0.0",
-    "react-addons-test-utils": "^15.4.2",
-    "babel-preset-es2015": "^6.22.0",
-    "react-test-renderer": "^15.4.2"
   }
 }