babel-preset-react-app doesn't transpile Object.values

[3stacks]

Is this a bug report?

yes

Did you try recovering your dependencies?

yep

Which terms did you search for in User Guide?

I searched through the babel-preset-react-app documentation and source looking for config options etc

Environment

Environment:
OS: macOS High Sierra 10.13.4
Node: 10.9.0
Yarn: 1.9.4
npm: 6.2.0
Watchman: Not Found
Xcode: Not Found
Android Studio: Not Found

Packages: (wanted => installed)
react: ^16.5.1 => 16.5.1
react-dom: ^16.5.1 => 16.5.1

Steps to Reproduce

demonstration: https://github.com/3stacks/but-why

1. Clone repository
2. yarn install
3. yarn build
4. Go to build/static/js/main.xxx.js
5. Search for "Object.values"

Expected Behavior

It should be transpiling es2017 features. Or if it doesn't by default, it should listen to my browserslist query and support the version of IE I defined, therefore transpiling object.values

Actual Behavior

It spat out Object.values in the built verison.

[gaearon]

A Babel preset isn't expected to fill in runtime features. It's not even possible to do reliably automatically unless you always bring in a polyfill.

It's meant to provide support for syntax. It's on you to choose the polyfills for your environment.

[3stacks]

Thanks for the info, is this what I'm looking for? https://babeljs.io/docs/en/babel-plugin-transform-runtime

[gaearon]

Stuff like this is not reliable. For example

const o = Object
o.values(); // babel can't find it

If you need to polyfill, do it by importing a polyfill — not via a transform.

[3stacks]

Oh right, gotcha. Thanks for pointing me in the right direction