Upgrade with-jest-typescript example to next 6.0.0 (#4543)

Hello! I ran into an issue using typescript and jest with next 6.0.0. I was able to work through fixing it and I wanted to share my solution back to next.js, by upgrading the with-jest-typescript example to next 6.0.0.

The steps I followed were:

1. `npx babel-upgrade --write` which added babel-core@^7.0.0-bridge.0 to allow jest's babel 6 to play nice with next's babel 7
2. Remove `ts-jest` and replace with `babel-jest` to use babel to transform the typescript code, as is done when the dev and production builds run
3. Update the babelrc to use commonjs modules in test mode to be compatible with jest

Also, I removed the `NODE_ENV=test` on the jest task, because jest sets the env to test anyways, and I'm on windows where this code is incorrect. The other option is to use `cross-env` but I felt it was simpler to just remove the environment override.

To my knowledge, this PR would help on the following issues:

#3663 #4227 #4531 #4528 #4239

examples/with-jest-typescript/.babelrc

@@ -1,6 +1,29 @@
 {
-  "presets": [
-    "next/babel",
-    "@zeit/next-typescript/babel"
-  ]
-}
+  "env": {
+    "development": {
+      "presets": [
+        "next/babel",
+        "@zeit/next-typescript/babel"
+      ]
+    },
+    "production": {
+      "presets": [
+        "next/babel",
+        "@zeit/next-typescript/babel"
+      ]
+    },
+    "test": {
+      "presets": [
+        [
+          "next/babel",
+          {
+            "preset-env": {
+              "modules": "commonjs"
+            }
+          }
+        ],
+        "@zeit/next-typescript/babel"
+      ]
+    }
+  }
+}

examples/with-jest-typescript/jest.config.js

@@ -2,14 +2,9 @@ const TEST_REGEX = '(/__tests__/.*|(\\.|/)(test|spec))\\.(jsx?|js?|tsx?|ts?)$'
 
 module.exports = {
   setupFiles: ['<rootDir>/jest.setup.js'],
-  globals: {
-    'ts-jest': {
-      'useBabelrc': true
-    }
-  },
   testRegex: TEST_REGEX,
   transform: {
-    '^.+\\.tsx?$': 'ts-jest'
+    '^.+\\.tsx?$': 'babel-jest'
   },
   testPathIgnorePatterns: [
     '<rootDir>/.next/', '<rootDir>/node_modules/'

examples/with-jest-typescript/package.json

@@ -2,28 +2,29 @@
   "name": "with-jest-typescript",
   "version": "1.0.0",
   "scripts": {
-    "test": "NODE_ENV=test jest",
+    "test": "jest",
     "dev": "next",
     "build": "next build",
     "start": "next start"
   },
   "dependencies": {
-    "next": "^5.0.0",
+    "next": "^6.0.0",
     "react": "^16.2.0",
     "react-dom": "^16.2.0"
   },
   "devDependencies": {
-    "@types/jest": "^22.2.2",
+    "@types/jest": "^23.0.0",
     "@types/next": "^2.4.8",
     "@types/react": "^16.0.41",
     "@types/react-dom": "^16.0.4",
     "@zeit/next-typescript": "1.0.1",
+    "babel-core": "^7.0.0-bridge.0",
+    "babel-jest": "23.0.1",
     "enzyme": "^3.3.0",
     "enzyme-adapter-react-16": "^1.1.1",
-    "jest": "^22.4.3",
+    "jest": "^23.1.0",
     "react-addons-test-utils": "^15.6.2",
     "react-test-renderer": "^16.2.0",
-    "ts-jest": "^22.4.2",
     "typescript": "^2.7.2"
   }
 }