[Bug]: TypeError: Cannot set properties of undefined (setting 'kind')

[reesscot]

💻

• Would you like to work on a fix?

How are you using Babel?

Other (Next.js, Gatsby, vue-cli, ...)

Input code

Seeing the error:

Cannot set properties of undefined (setting 'kind')

Seems related to #15300 and

Configuration file name

No response

Configuration

No response

Current and expected behavior

After release @babel/plugin-transform-block-scoping v7.20.8 seeing the error above.

Environment

System:
OS: macOS 12.6.1
Binaries:
Node: 16.16.0 - ~/.nvm/versions/node/v16.16.0/bin/node
Yarn: 1.22.19 - ~/.nvm/versions/node/v16.16.0/bin/yarn
npm: 8.11.0 - ~/.nvm/versions/node/v16.16.0/bin/npm

Possible solution

Does #15200 need to be reverted until the issues are all fixed?

Additional context

No response

[babel-bot]

Hey @reesscot! We really appreciate you taking the time to report an issue. The collaborators on this project attempt to help as many people as possible, but we're a limited number of volunteers, so it's possible this won't be addressed swiftly.

If you need any help, or just have general Babel or JavaScript questions, we have a vibrant Slack community that typically always has someone willing to help. You can sign-up here for an invite.

[pgaurav9]

We are also experiencing a similar issue for a react-app with the following versions:

• node: 8.12.0
• npm: 6.4.1

The earlier error was TypeError: 'constantViolations' of undefined however now it's TypeError: Cannot set property 'kind' of undefined. Since our project is working on an old package version so we wanted to be sure whether it's a deprecation of babel dependency that we are using or something else. Kindly provide an update on this.

[nicolo-ribaudo]

A fix would be checking that every call to scope.getOwnBinding in https://github.com/babel/babel/tree/main/packages/babel-plugin-transform-block-scoping/src can return null. I can probably work on a PR in a few hours, tomorrow morning (EU) at latest, but if someone else wants to open the PR it would be much appreciated.

[liuxingbaoyu]

I found two places, one of which I'm not sure how to do.

[nicolo-ribaudo]

Maybe in the second one we could run a crawl if the binding is not present.

[rotten-bmiller]

I went back a version for @babel/plugin-transform-block-scoping and my react application is now building successfully again.
npm i @babel/plugin-transform-block-scoping@7.20.5

[ndelangen]

I'm 100% willing to help out, however I do not have sufficient knowledge to understand:

Maybe in the second one we could run a crawl if the binding is not present.

@liuxingbaoyu you seem to have 👍'd it, do you understand? Do you want help?

[ndelangen]

I'm also a bit hesitant to ask.. but would a roll-back to 7.20.5 be an option? Meaning releasing a new patch with the contents of 7.20.5?

I could provide a environment, in which you can replace some node_modules content and a command to run to reproduce the problem in "isolation"...

[gabriels1234]

Thanks, this is a good work-around for now.
A note to self, when dealing with these types of issues, make sure versions are pinned:
"@babel/core": "7.20.5",
vs "@babel/core": "^7.20.5", (does not fix the issue)

[liuxingbaoyu]

@ndelangen v7.20.9 has been released, has the problem been solved?

[ndelangen]

Going to try now!

[ndelangen]

Looking positive!

[barbalex]

can't find v7.20.9: https://www.npmjs.com/package/@babel/core?activeTab=versions

[nicolo-ribaudo]

@barbalex The bug/fix is in @babel/plugin-transform-block-scoping

[barbalex]

@nicolo-ribaudo Thanks!
My project has not explicitely included @babel/plugin-transform-block-scoping so far. So I:

• npm i --dev @babel/plugin-transform-block-scoping
• added "@babel/plugin-transform-block-scoping": "7.20.9" as overrides to package.json

and the build works again!

Thanks so much for your effort and help!

[mccoinu]

Hi I had the same problem,
First with the message:
TypeError: 'constantViolation' of undefined
then:
TypeError: Cannot set property 'kind' of undefined.

By setting
"@babel/core": "7.20.5"

I solved.

Thank you

[nicolo-ribaudo]

@barbalex Now you can also remove it from your package.json! The process you did updated the your lockfile, and now that the lockfile is updated you won't get the old version anymore :)

[barbalex]

@nicolo-ribaudo Wow. The marvels of lockfiles. Glad to be helped by guys with more insight!

[reesscot]

I can confirm that I'm no longer seeing the error after installing @babel/plugin-transform-block-scoping@7.20.9

[ndelangen]

Thank you @nicolo-ribaudo and everyone else that helped.

I wish I could have done more to help myself.

Really truly appreciative of the quick fixes, thank you.