From 062be50b00d413edcb8cfd18948c86ec13b1fae8 Mon Sep 17 00:00:00 2001
From: Joe Haddad <timer150@gmail.com>
Date: Tue, 25 Sep 2018 16:08:29 -0400
Subject: [PATCH] Drop IE 11 support by default (#5090)

* Drop ie 11 support and move polyfills to a new package

* More useful directions for what entry point to use
https://github.com/facebook/create-react-app/pull/5090#discussion_r220313783

* Clear up what file this polyfill goes in
https://github.com/facebook/create-react-app/pull/5090#discussion_r220313980

* Polyfill `window`, not `global`

* Remove proxy polyfill file
---
 config/polyfills.js               | 30 ------------------------------
 config/webpack.config.dev.js      |  3 ---
 config/webpack.config.prod.js     |  4 ++--
 package.json                      |  7 ++-----
 scripts/utils/createJestConfig.js |  2 +-
 5 files changed, 5 insertions(+), 41 deletions(-)
 delete mode 100644 config/polyfills.js

diff --git a/config/polyfills.js b/config/polyfills.js
deleted file mode 100644
index 8d97fb4ac39..00000000000
--- a/config/polyfills.js
+++ /dev/null
@@ -1,30 +0,0 @@
-// @remove-on-eject-begin
-/**
- * Copyright (c) 2015-present, Facebook, Inc.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-// @remove-on-eject-end
-'use strict';
-
-if (typeof Promise === 'undefined') {
-  // Rejection tracking prevents a common issue where React gets into an
-  // inconsistent state due to an error, but it gets swallowed by a Promise,
-  // and the user has no idea what causes React's erratic future behavior.
-  require('promise/lib/rejection-tracking').enable();
-  window.Promise = require('promise/lib/es6-extensions.js');
-}
-
-// fetch() polyfill for making API calls.
-require('whatwg-fetch');
-
-// Object.assign() is commonly used with React.
-// It will use the native implementation if it's present and isn't buggy.
-Object.assign = require('object-assign');
-
-// In tests, polyfill requestAnimationFrame since jsdom doesn't provide it yet.
-// We don't polyfill it in the browser--this is user's responsibility.
-if (process.env.NODE_ENV === 'test') {
-  require('raf').polyfill(global);
-}
diff --git a/config/webpack.config.dev.js b/config/webpack.config.dev.js
index 13fe5cafc24..24f51c018b7 100644
--- a/config/webpack.config.dev.js
+++ b/config/webpack.config.dev.js
@@ -82,10 +82,7 @@ module.exports = {
   devtool: 'cheap-module-source-map',
   // These are the "entry points" to our application.
   // This means they will be the "root" imports that are included in JS bundle.
-  // The first two entry points enable "hot" CSS and auto-refreshes for JS.
   entry: [
-    // We ship a few polyfills by default:
-    require.resolve('./polyfills'),
     // Include an alternative client for WebpackDevServer. A client's job is to
     // connect to WebpackDevServer by a socket and get notified about changes.
     // When you save a file, the client will either apply hot updates (in case
diff --git a/config/webpack.config.prod.js b/config/webpack.config.prod.js
index af250048d14..76e767faddf 100644
--- a/config/webpack.config.prod.js
+++ b/config/webpack.config.prod.js
@@ -100,8 +100,8 @@ module.exports = {
   // We generate sourcemaps in production. This is slow but gives good results.
   // You can exclude the *.map files from the build during deployment.
   devtool: shouldUseSourceMap ? 'source-map' : false,
-  // In production, we only want to load the polyfills and the app code.
-  entry: [require.resolve('./polyfills'), paths.appIndexJs],
+  // In production, we only want to load the app code.
+  entry: [paths.appIndexJs],
   output: {
     // The build folder.
     path: paths.appBuild,
diff --git a/package.json b/package.json
index 93627fd1db2..c632cecbb9c 100644
--- a/package.json
+++ b/package.json
@@ -50,14 +50,12 @@
     "jest": "23.6.0",
     "loader-utils": "1.1.0",
     "mini-css-extract-plugin": "0.4.3",
-    "object-assign": "4.1.1",
     "optimize-css-assets-webpack-plugin": "5.0.1",
     "postcss-flexbugs-fixes": "4.1.0",
     "postcss-loader": "3.0.0",
     "postcss-preset-env": "6.0.6",
     "postcss-safe-parser": "4.0.1",
-    "promise": "8.0.2",
-    "raf": "3.4.0",
+    "react-app-polyfill": "^0.0.0",
     "react-dev-utils": "^5.0.0",
     "resolve": "1.8.1",
     "sass-loader": "7.1.0",
@@ -68,8 +66,7 @@
     "url-loader": "1.1.1",
     "webpack": "4.19.1",
     "webpack-dev-server": "3.1.9",
-    "webpack-manifest-plugin": "2.0.4",
-    "whatwg-fetch": "3.0.0"
+    "webpack-manifest-plugin": "2.0.4"
   },
   "devDependencies": {
     "react": "^16.3.2",
diff --git a/scripts/utils/createJestConfig.js b/scripts/utils/createJestConfig.js
index c077746a9e2..22e52dbdca4 100644
--- a/scripts/utils/createJestConfig.js
+++ b/scripts/utils/createJestConfig.js
@@ -22,7 +22,7 @@ module.exports = (resolve, rootDir, isEjecting) => {
   // in Jest configs. We need help from somebody with Windows to determine this.
   const config = {
     collectCoverageFrom: ['src/**/*.{js,jsx}'],
-    setupFiles: [resolve('config/polyfills.js')],
+    setupFiles: ['react-app-polyfill/jsdom'],
     setupTestFrameworkScriptFile: setupTestsFile,
     testMatch: [
       '<rootDir>/src/**/__tests__/**/*.{js,jsx}',