[Bug]: plugin-transform-regenerator together with async-to-generator incorrectly shadow function name in local scope

[larabr]

💻

• Would you like to work on a fix?

How are you using Babel?

@babel/cli

Input code

I have a REPL of the large minified build where we encountered the bug. Unfortunately, while I could track down the incriminated plugins, I haven't managed to single out a smaller portion of code where the bug could be reproduced.

REPL

Configuration file name

No response

Configuration

npx babel --plugins=@babel/plugin-transform-destructuring,@babel/plugin-transform-for-of,@babel/plugin-transform-spread,@babel/plugin-transform-classes,@babel/plugin-transform-regenerator, @babel/plugin-transform-regenerator, @babel/plugin-transform-async-to-generator

Current and expected behavior

Current (line references based on the REPL): the class n declared at L7 and instantiated in the function Rr at L3297 of the original code is shadowed by a var declaration in the transformed code (at L5599). As a result, the instantiation fails due to n being undefined.

Expected: the var declaration uses a different name.

Environment

Babel: 7.23.9 (@babel/core 7.23.9)
OS: macOS 12.7.2
Node: 20.11.0
Yarn: 4.1.0 
npm: 8.15.0

Possible solution

Not really a solution, but excluding either @babel/plugin-transform-async-to-generator or @babel/plugin-transform-regenerator fixes the issue.

Additional context

I noticed that dropping the code after the affected function (Rr) results in a correct transformation, hence something in the rest of the code must be playing a role too.

[babel-bot]

Hey @larabr! 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.

[OctopusRoe]

I have encountered a similar issue as well. Whenever I use destructuring assignment within an asynchronous function, like const {a, b} = await request(), I encounter an error related to an undefined type. In my case, I was able to successfully build my project by excluding the @babel/plugin-transform-regenerator plugin.