Syntax error - IE10 - Polyfill - Development Mode

Is this a bug report?

Yes

Did you try recovering your dependencies?

No, it’s a fresh project.

Which terms did you search for in User Guide?

(Write your answer here if relevant.)

Environment

Environment Info:

System: OS: Windows 10 CPU: (8) x64 Intel® Core™ i7-2600K CPU @ 3.40GHz Binaries: Node: 10.15.3 - C:\Program Files\nodejs\node.EXE Yarn: Not Found npm: 6.4.1 - C:\Program Files\nodejs\npm.CMD Browsers: Edge: 42.17134.1.0 Internet Explorer: 11.0.17134.1 npmPackages: react: ^16.8.6 => 16.8.6 react-dom: ^16.8.6 => 16.8.6 react-scripts: 3.0.0 => 3.0.0 npmGlobalPackages: create-react-app: Not Found

Steps to Reproduce

(Write your steps here:)

1. Create a new project with npx create-react-app my-app
2. I need ie10 compatibility so do: npm install react-app-polyfill
3. Include these 2 lines at the top in index.js: import ‘react-app-polyfill/ie9’; import ‘react-app-polyfill/stable’;
4. Add “ie 10” to browserslist both for production and development
5. Save + npm start.

Expected Behavior

I would see the react svg logo and the default text and background color in IE10, with no script error in IE’s dev tools console.

Actual Behavior

IE displays a blank white page with some Javascript errors in the console (attached screenshot). A “Map is undefined” error appear in ansi-colors index.js node_modules. I follow all the steps of #6924 but it doesn’t work for ie10.

Reproducible Demo

(Paste the link to an example project and exact instructions to reproduce the issue.)

[ianschmitz]

Ah i think i figured out what’s happengin @amerej. The error overlay unfortunately doesn’t work in browsers older than ie 11 currently it appears. The error overlay code loads before your application code, so your attempts to polyfill won’t work. This is a known issue. I’m going to close this in favor of the existing issue.

By the way, just a heads up that our default production browserslist includes not dead, which will exclude ie 10 if you were to add it before not dead in the list. You can see what i mean here: https://browserl.ist/?q=ie+9%2C+ie+10%2C+ie+11%2C+not+dead. Adding it after should work as expected though: https://browserl.ist/?q=ie+9%2C+ie+11%2C+not+dead%2C+ie+10

[amerej]

@ianschmitz it works!, Thank you.