Minify option incorrectly strips escape characters

[SarahAnnTolsma]

Describe the bug

When escaping specific strings, SWC strips necessary escape characters in minified output. This results in the incorrect string being output. See the given input code and playground link for examples.

Input code

let str = "\\uD83D\\uDC68\\u200D\\uD83D\\uDE80";

let obj = {
    "\\uD83D\\uDC68\\u200D\\uD83D\\uDE80": "wrong"
};

Config

{
  "jsc": {
    "parser": {
      "syntax": "typescript",
      "tsx": false
    },
    "target": "es2015",
    "loose": false,
    "minify": {
      "compress": false,
      "mangle": false
    }
  },
  "module": {
    "type": "commonjs"
  },
  "minify": true,
  "isModule": false
}

Playground link

https://play.swc.rs/?version=1.3.70&code=H4sIAAAAAAAAA8tJLVEoLilSsFVQiokpdbEwdgFRzmYWQMrIwMAFSdDVwkDJmosrB6gjPykLqKOaSwEIiNJnpaBUXpSfl67EVWsNAEudP25zAAAA&config=H4sIAAAAAAAAA1VPOw7DIAzdcwrkuUNbqUvv0EMg6kRE%2FIQdqSjK3QME2maz39deByFgJgVPseYxL0FGwvjdM0LJsfxkBDgFJBV1YLh0lqlQozSEFdoOBljGCbm4kO7X26M5wHhP2B0Ns9rpMf13Km9DRKKzsEilmwyeG4fWCta%2Fl0q2X8q95YKcZr2bCX7K3shxqeGg6dXdR%2FS2AzVy5M4cAQAA

Expected behavior

SWC should not strip escape characters and produce the following output:

let str="\\uD83D\\uDC68\\u200D\\uD83D\\uDE80";let obj={"\\uD83D\\uDC68\\u200D\\uD83D\\uDE80":"wrong"};

Actual behavior

SWC strips escape characters and produces the following output:

let str="\uD83D\uDC68\\u200D\uD83D\uDE80";let obj={"\uD83D\uDC68\\u200D\uD83D\uDE80":"wrong"};

Note the missing \ before \uD83D (twice), \uDC68 and \uDE80.

Version

1.3.70

Additional context

As a workaround, the following produces the correct output:

let workaround = {
    [`\\uD83D\\uDC68\\u200D\\uD83D\\uDE80`]: "correct",
};

[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.