Add ESM build to react-is

[pgarciacamou]

Do you want to request a feature or report a bug?

Feature

What is the current behavior?

Unable to import individual modules from the package.

import * as ReactIs from "react-is";
ReactIs.isValidElementType(<div />); // true

What is the expected behavior?

import { isValidElementType } from "react-is";
isValidElementType(<div />); // true

Context

This issue arose when trying to to make react-redux work with React.forwardRef (see this PR), but evidently, react-is doesn't allow import/export ESM to enable tree shaking capabilities in react-redux (that is my understanding).

This issue is following this comment.

I tried solving this (and totally failed) in #13250 before I realised anything about ESM. But this is now over my head, so I'm creating an issue now and see how that follows.

[gaearon]

You can't make it work by changing the source — you'll want to change the build scripts (scripts/rollup/*) to target an ESM build.

[TrySound]

FYI I'm working on this.

[kentcdodds]

Could we change this issue (or should I open a new issue) to apply this to all react packages? Rollup has trouble when dependencies use React like it has an ESM export but it actually doesn't :-(

Ref: reach/reach-ui#74

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contribution.

[TrySound]

Not stale.

[stale]

This issue has been automatically marked as stale. If this issue is still affecting you, please leave any comment (for example, "bump"), and we'll keep it open. We are sorry that we haven't been able to prioritize it yet. If you have any new additional information, please include it with your comment!

[stale]

Closing this issue after a prolonged period of inactivity. If this issue is still present in the latest release, please create a new issue with up-to-date information. Thank you!

[jacksteamdev]

Not stale.