Downgrade Jest version so it works with V3

Adjust a few bits so that Jest works properly with V3

Add property to jest config for matching jest files in this lower version of jest

Author: JamieDixon

packages/react-scripts/config/jest/babelTransform.js

@@ -12,5 +12,5 @@ const babelJest = require('babel-jest');
 
 module.exports = babelJest.createTransformer({
   presets: [require.resolve('babel-preset-react-app')],
-  babelrc: false,
+  babelrc: true,
 });

packages/react-scripts/package.json

@@ -25,7 +25,7 @@
     "autoprefixer": "7.1.2",
     "babel-core": "6.25.0",
     "babel-eslint": "7.2.3",
-    "babel-jest": "20.0.3",
+    "babel-jest": "^16.0.0",
     "babel-loader": "7.1.1",
     "babel-preset-react-app": "^3.0.2",
     "babel-runtime": "6.23.0",
@@ -44,7 +44,7 @@
     "file-loader": "0.11.2",
     "fs-extra": "3.0.1",
     "html-webpack-plugin": "2.29.0",
-    "jest": "20.0.4",
+    "jest": "^16.0.1",
     "object-assign": "4.1.1",
     "postcss-cssnext": "^3.0.2",
     "postcss-flexbugs-fixes": "3.2.0",

packages/react-scripts/scripts/utils/createJestConfig.js

@@ -26,6 +26,7 @@ module.exports = (resolve, rootDir, isEjecting) => {
     collectCoverageFrom: ['src/**/*.{js,jsx}'],
     setupFiles: [resolve('config/polyfills.js')],
     setupTestFrameworkScriptFile: setupTestsFile,
+    testRegex: 'jest\\.js$',
     testMatch: [
       '<rootDir>/src/**/__tests__/**/*.js?(x)',
       '<rootDir>/src/**/?(*.)(spec|test).js?(x)',
@@ -42,6 +43,9 @@ module.exports = (resolve, rootDir, isEjecting) => {
     transformIgnorePatterns: ['[/\\\\]node_modules[/\\\\].+\\.(js|jsx)$'],
     moduleNameMapper: {
       '^react-native$': 'react-native-web',
+      '^.+\\.css$': '<rootDir>/scripts/utils/css-stub.js',
+      '^.+\\.(jpg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm)$':
+        '<rootDir>/scripts/utils/file-stub.js',
     },
     moduleFileExtensions: ['web.js', 'js', 'json', 'web.jsx', 'jsx', 'node'],
   };