Block scoping of const is broken when transpiling to ES5

[damiantew]

Describe the bug

Attached code incorrectly transpiles in SWC target ES5:
6 is logged 7 times instead of each number logged once as per const scoping behaviors in ES6.
Wrapping with the async function appears to be necessary to trigger the error

Input code

async function a() {
    for (const number_in_a_sequence of Array.from(new Array(7), (_,i) => i)) {
        setTimeout(() => console.log(number_in_a_sequence), 10)
    }
}
a()

Config

default playground configuration

Playground link

https://play.swc.rs/?version=1.2.119&code=H4sIAAAAAAAAA22OzQrCMBCE74W%2Bwxw3UIqePCn4Dt5DDBsJtLuYH0oR393UgieHuQwD34zLq3iEKr5EFTgyePUdmoImkFfJBVLnOycbxTqb%2BVlZPEMDrim5dQxJZxJe9kgnM4DsEA3OF0Tz423KXG5xZq2F6NtvfJ14nPRB%2F1Ya63gwO%2BDdd83t4Qe5CcJstAAAAA%3D%3D&config=H4sIAAAAAAAAA0WMTQrEIAxG75K1286id5hDBCctFv9IUhgR714tlu7C915ehUMsrBUyshCPS0pU%2FMMKZAOKZZcVTNf6tKEXagYUeScdiiyd%2BZSEJjUQXHRbGSWbQmYSeRHG3T9m66GQfucYKmjJdAc%2F0N7G%2FHPynaLySe0Cj9ke9LUAAAA%3D

Expected behavior

each number from 0 to 6 should be logged once as per const binding behaviors in ES6.

Version

1.2.119

Additional context

No response

[kwonoj]

master seems to be fixed, need double confirm once new version's published.

[kdy1]

I investigated this, and the cause was that regenerator pass not considering block scoping of const number_in_a_sequence.

[swc-bot]

This closed issue has been automatically locked because it had no new activity for a month. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.