React: UMD build doesn't work via import in the browser (TypeError: Cannot set property 'React' of undefined)

[vp2177]

When importing the UMD build (both production and development) in the browser – that is, from a <script type="module"> – an error is thrown: TypeError: Cannot set property 'React' of undefined.

The relevant code:

12: (function (global, factory) {
13: typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
14: typeof define === 'function' && define.amd ? define(factory) :
15: (global.React = factory());
16: }(this, (function () { 'use strict';

Throws on line 15 as global ≣ this is undefined in a module context.
Is this as simple to fix as passing this || self on line 16, or is there a catch?

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

What is the current behavior?
TypeError: Cannot set property 'React' of undefined

If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem.
https://jsfiddle.net/dja3wfc7/ (_Updated_)

What is the expected behavior?
I would expect the import to work, as the same file works if included via <script src=...>.

Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?
React 16.7.0 (latest stable) – I have found another UMD related bug, #3037, which pertains to React 0.12.2. I have tried that version and indeed it works, it can be imported.
Chrome 71, Safari 12 tested (probably all browsers)

[gaearon]

It's not expected that UMD imports would work with import — you want ESM builds (which we don't offer yet).

[vp2177]

@gaearon I have looked into why the UMD build doesn't work, as I thought it should. (Of course an ESM build would be better, but in the meantime...)

It is because rollup ^0.52.1 is used for the build. I haven't tracked down when this was fixed in rollup but the current version (1.1.2) produces a correct UMD, which works in a module context.

Is it feasible to upgrade the rollup dependency, or is there a reason to stick with that old version?

[gaearon]

I don't remember a particular reason. If you send a PR upgrading Rollup we can look at it!

[kunukn]

I don't remember a particular reason. If you send a PR upgrading Rollup we can look at it!

https://github.com/facebook/react/pull/15037

[stale[bot]]

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.

[stale[bot]]

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!