incorrect scope of declarations surrounding using declarations

[tjjfvi]

Describe the bug

SWC incorrectly handles the scope of declarations surrounding using declarations.

Input code

using foo = null

const bar = 1

console.log(baz())

function baz() {
  return bar
}

Config

{
  "jsc": {
    "parser": {
      "syntax": "typescript",
      "tsx": false
    },
    "loose": false,
    "minify": {
      "compress": false,
      "mangle": false
    },
    "target": "es2022",
  },
  "module": {
    "type": "es6"
  },
  "minify": false,
  "isModule": true,
}

Playground link

https://play.swc.rs/?version=1.3.90&code=H4sIAAAAAAAAAyXIPQrAIAwG0D2n%2BEZdCj1AD6OiUggJRLO09O79G9%2FzsUtHU8UGcWaiojImcrJn1p%2FKdWHtIacjxEjUXMrcVfAFTgKsTrc3jK4b1lYZUlQAAAA%3D&config=H4sIAAAAAAAAA22PPQ7CMAyFd04ReWZAGRi4A4eIglsF5U%2B2K1FVvTtJ2hSQ2Oz3PdvPy0kpeLKFm1pKWZpsiJGOvig8RzGvooDMGdmSywLnToUrGoxnbNK6EfApMXaya8FFN8zfu20KmZD511itJo4e%2F24WQyNKzYOsL1q3LA1CSI%2BpTe3P1MCb8QofU09xXATH9z4pNBVtfQNyL9zVGQEAAA%3D%3D

SWC Info output

(N/A; reproduced using Deno / SWC playground)

Expected behavior

The transpiled program prints 1.

Actual behavior

The bar constant is defined inside the try block, rendering it inaccessible to the function baz, which is defined outside of the try block. This results in a ReferenceError at runtime.

Version

1.3.90

Additional context

When target is ES5, this actually works correctly, due to the const being transformed to a var.

As a point of comparison, TSC transpiles this with a var bar; statement outside of the try, even when target is set above ES5.

[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.