Export is not defined

[jaejun-choi]

Bug Report

Current Behavior
SyntaxError: Export 'Foo' is not defined

Input Code

interface Foo {}

export type { Foo }

Expected behavior/code
no error

Babel Configuration (.babelrc, package.json, cli command)
flow plugin

Environment

• Babel version(s): 7.4.5
• Node/npm version: Node 11.13 / npm 6.7

Possible Solution
flowParseInterfaceish() should call checkLVal() or scope.declareName()

[babel-bot]

Hey @jj-choi! 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
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[ksocha]

I've encountered similar issue with @babel/plugin-transform-typescript@7.4.5. Everything works fine with @babel/plugin-transform-typescript@7.4.4

[JoshRobertson]

I've also encountered this issue upgrading from 7.4.4 to 7.4.5

[tanhauhau]

@ksocha @JoshRobertson could you guys explain more on the specific code that produces error in typescript?

I couldn't replicate it

[ksocha]

@tanhauhau

I've created a repo using create-react-app that replicates the issue: https://github.com/ksocha/typescript-plugin-issue

With 7.4.5, you'll see that exported function is undefined.
Works fine with 7.4.4.

You can change versions by modifying resolutions entry in package.json.

[JLHwung]

@ksocha Thanks for the reproduction repo! However, I can not reproduce this issue with @babel/plugin-transform-typescript 7.5.2 on your repo. Looking to the commit history, it should be related to #9944 but later it has been fixed on 7.5.0.

jj-choi's issue can be reproduced at REPL.

[boris-petrov]

@JLHwung - did you manage to catch the issue? Because I have the same issue even on the latest 7.5.4 version.

[JLHwung]

@boris-petrov I assume you mean the issue submitted by the OP. And yes, the issue can be reproduced.

If you mean the issue submitted by @ksocha, I could not reproduce on his repo.

[boris-petrov]

@JLHwung - sorry, yes, I mean the original issue. Great, so we'll be expecting a fix soon, thanks!