upgrade to react-scripts 4.0.1

I'm naively hoping that this fixes the issue with Emotion/Chakra styles that only shows up on prod…

We've had an issue with prod-only bugs before, and it was due to a compiler bug re comments in JSX. I'm wondering if maybe one of our deps now has the same or a similar bug? and if maybe upgrading react-scripts will upgrade webpack, which might fix it?

It's a bit of a longshot, but it's a good upgrade to do anyway, so let's see if we get lucky!

Also, react-scripts 4 has Fast Refresh built in, so we can remove our overrides that added it!

.gitignore

@@ -1,8 +1,3 @@
-.env
-.now
-
-# See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
-
 # dependencies
 /node_modules
 /.pnp
@@ -16,10 +11,12 @@
 
 # misc
 .DS_Store
+.env
 .env.local
 .env.development.local
 .env.test.local
 .env.production.local
+.eslintcache
 
 npm-debug.log*
 yarn-debug.log*

config-overrides.js

@@ -1,4 +0,0 @@
-const { override } = require("customize-cra");
-const { addReactRefresh } = require("customize-cra-react-refresh");
-
-module.exports = override(addReactRefresh());

package.json

@@ -38,15 +38,15 @@
     "react-dom": "^16.13.1",
     "react-icons": "^3.11.0",
     "react-router-dom": "^5.1.2",
-    "react-scripts": "3.4.1",
+    "react-scripts": "^4.0.1",
     "react-transition-group": "^4.3.0",
     "react-virtualized": "^9.22.2",
     "simple-markdown": "^0.7.2",
     "xmlrpc": "^1.3.2"
   },
   "scripts": {
-    "start": "yarn build-cached-data && react-app-rewired start",
-    "build": "yarn build-cached-data && react-app-rewired build",
+    "start": "yarn build-cached-data && react-scripts start",
+    "build": "yarn build-cached-data && react-scripts build",
     "test": "react-app-rewired test --env=jsdom",
     "eject": "react-scripts eject",
     "mysql": "mysql --host=impress.openneo.net --user=$(dotenv -p IMPRESS_MYSQL_USER) --password=$(dotenv -p IMPRESS_MYSQL_PASSWORD) --database=openneo_impress",
@@ -86,13 +86,10 @@
     "@storybook/react": "^6.0.21",
     "apollo-server-testing": "^2.12.0",
     "auth0": "^2.28.0",
-    "customize-cra": "^1.0.0",
-    "customize-cra-react-refresh": "^1.1.0",
     "dotenv-cli": "^3.1.0",
     "es6-promise-pool": "^2.5.0",
     "inquirer": "^7.3.3",
     "prettier": "^2.0.5",
-    "react-app-rewired": "^2.1.6",
     "react-is": "^16.13.1"
   }
 }