From a67050f2a5d10fd42f79ecb58983ecff39769094 Mon Sep 17 00:00:00 2001
From: Dan Abramov <dan.abramov@gmail.com>
Date: Wed, 3 Oct 2018 19:47:58 +0100
Subject: [PATCH] Disable Symbol typeof transform

---
 packages/babel-preset-react-app/create.js       | 2 ++
 packages/babel-preset-react-app/dependencies.js | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/packages/babel-preset-react-app/create.js b/packages/babel-preset-react-app/create.js
index 52f0fa14bb7..17a5319388e 100644
--- a/packages/babel-preset-react-app/create.js
+++ b/packages/babel-preset-react-app/create.js
@@ -82,6 +82,8 @@ module.exports = function(api, opts, env) {
           useBuiltIns: false,
           // Do not transform modules to CJS
           modules: false,
+          // Exclude transforms that make all code slower
+          exclude: ['transform-typeof-symbol'],
         },
       ],
       [
diff --git a/packages/babel-preset-react-app/dependencies.js b/packages/babel-preset-react-app/dependencies.js
index 19a6e74557b..60c76fb5b3a 100644
--- a/packages/babel-preset-react-app/dependencies.js
+++ b/packages/babel-preset-react-app/dependencies.js
@@ -76,6 +76,8 @@ module.exports = function(api, opts) {
           },
           // Do not transform modules to CJS
           modules: false,
+          // Exclude transforms that make all code slower
+          exclude: ['transform-typeof-symbol'],
         },
       ],
       (isEnvProduction || isEnvDevelopment) && [
@@ -95,6 +97,8 @@ module.exports = function(api, opts) {
           useBuiltIns: false,
           // Do not transform modules to CJS
           modules: false,
+          // Exclude transforms that make all code slower
+          exclude: ['transform-typeof-symbol'],
         },
       ],
     ].filter(Boolean),