[Next 9] Importing react-dom would bloat the bundle size

Bug report

Describe the bug

Importing react-dom in a page or in one of its dependent component will cause react-dom.production.min.js to be included in the page bundle, adding about 32K gzipped size to a page.

This is pretty common, examples:

• ReactDOM.createPortal
• react-transition-group also imports react-dom

To Reproduce

Steps to reproduce the behavior, please provide code snippets or a repository:

1. Go to ‘pages/any-page.js’
2. Add import ReactDOM from 'react-dom';
3. In the render function, do console.log(ReactDOM). Just to use that dependency.
4. Production build the project and inspect the bundle size

Expected behavior

react-dom should just be in the common bundle, not included again here. This does not happen with Next 8.

Screenshots

System information

• OS: macOS
• Version of Next.js: 9.0.1

Additional context

Add any other context about the problem here.

[timneutkens]

@zenozen it’s fixed in the new chunking behavior:

module.exports = {
  experimental: {
    granularChunks: true
  }
}

[balazsorban44]

This issue has been automatically locked due to no recent activity. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.