From 2300f9e9830b6bd04df253afc8121893789089ec Mon Sep 17 00:00:00 2001
From: Joe Haddad <timer150@gmail.com>
Date: Tue, 18 Sep 2018 14:31:02 -0400
Subject: [PATCH] Switch from uglifyjs to terser (#5026)

Uglify is no longer maintained and has bugs not present in Terser (its successor)
---
 packages/react-dev-utils/printBuildError.js           | 4 ++--
 packages/react-error-overlay/package.json             | 2 +-
 packages/react-error-overlay/webpack.config.iframe.js | 6 +++---
 packages/react-scripts/config/webpack.config.prod.js  | 8 ++++----
 packages/react-scripts/package.json                   | 2 +-
 5 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/packages/react-dev-utils/printBuildError.js b/packages/react-dev-utils/printBuildError.js
index 0fe7aa9a552..1e70b4e64f4 100644
--- a/packages/react-dev-utils/printBuildError.js
+++ b/packages/react-dev-utils/printBuildError.js
@@ -13,11 +13,11 @@ module.exports = function printBuildError(err) {
   const message = err != null && err.message;
   const stack = err != null && err.stack;
 
-  // Add more helpful message for UglifyJs error
+  // Add more helpful message for Terser error
   if (
     stack &&
     typeof message === 'string' &&
-    message.indexOf('from UglifyJs') !== -1
+    message.indexOf('from Terser') !== -1
   ) {
     try {
       const matched = /(.+)\[(.+):(.+),(.+)\]\[.+\]/.exec(stack);
diff --git a/packages/react-error-overlay/package.json b/packages/react-error-overlay/package.json
index 78f11363e98..abd51987ac2 100644
--- a/packages/react-error-overlay/package.json
+++ b/packages/react-error-overlay/package.json
@@ -60,7 +60,7 @@
     "rimraf": "^2.6.2",
     "settle-promise": "1.0.0",
     "source-map": "0.5.6",
-    "uglifyjs-webpack-plugin": "1.2.5",
+    "terser-webpack-plugin": "1.1.0",
     "webpack": "^4.8.1"
   },
   "jest": {
diff --git a/packages/react-error-overlay/webpack.config.iframe.js b/packages/react-error-overlay/webpack.config.iframe.js
index 3a806f362db..67157bad440 100644
--- a/packages/react-error-overlay/webpack.config.iframe.js
+++ b/packages/react-error-overlay/webpack.config.iframe.js
@@ -8,7 +8,7 @@
 
 const path = require('path');
 const webpack = require('webpack');
-const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
+const TerserPlugin = require('terser-webpack-plugin');
 
 module.exports = {
   mode: process.env.NODE_ENV === 'production' ? 'production' : 'development',
@@ -49,8 +49,8 @@ module.exports = {
     minimizer: [
       // This code is embedded as a string, so it would never be optimized
       // elsewhere.
-      new UglifyJsPlugin({
-        uglifyOptions: {
+      new TerserPlugin({
+        terserOptions: {
           compress: {
             warnings: false,
             comparisons: false,
diff --git a/packages/react-scripts/config/webpack.config.prod.js b/packages/react-scripts/config/webpack.config.prod.js
index 34a437afce9..5d92c9ef859 100644
--- a/packages/react-scripts/config/webpack.config.prod.js
+++ b/packages/react-scripts/config/webpack.config.prod.js
@@ -12,7 +12,7 @@ const autoprefixer = require('autoprefixer');
 const path = require('path');
 const webpack = require('webpack');
 const HtmlWebpackPlugin = require('html-webpack-plugin');
-const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
+const TerserPlugin = require('terser-webpack-plugin');
 const MiniCssExtractPlugin = require('mini-css-extract-plugin');
 const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');
 const ManifestPlugin = require('webpack-manifest-plugin');
@@ -115,10 +115,10 @@ module.exports = {
   },
   optimization: {
     minimizer: [
-      new UglifyJsPlugin({
-        uglifyOptions: {
+      new TerserPlugin({
+        terserOptions: {
           parse: {
-            // we want uglify-js to parse ecma 8 code. However, we don't want it
+            // we want terser to parse ecma 8 code. However, we don't want it
             // to apply any minfication steps that turns valid ecma 5 code
             // into invalid ecma 5 code. This is why the 'compress' and 'output'
             // sections only apply transformations that are ecma 5 safe
diff --git a/packages/react-scripts/package.json b/packages/react-scripts/package.json
index 2b444c0bded..0e639a768dd 100644
--- a/packages/react-scripts/package.json
+++ b/packages/react-scripts/package.json
@@ -64,8 +64,8 @@
     "style-loader": "0.21.0",
     "svgr": "1.9.2",
     "sw-precache-webpack-plugin": "0.11.5",
+    "terser-webpack-plugin": "1.1.0",
     "thread-loader": "1.2.0",
-    "uglifyjs-webpack-plugin": "1.2.5",
     "url-loader": "1.0.1",
     "webpack": "4.19.0",
     "webpack-dev-server": "3.1.7",