Unintended compressed with if_return flag

[kakao-aiden-ahn]

Describe the bug

Assume that the Deferred contained in window.current is resolved outside the script.

setTimeout(() => window.current.resolve('result'), 3000);

If normal, 'result' should appear when the logic below is executed.

bug().then(alert)

However, minify with swc, the error below occurs.

Uncaught TypeError: Cannot read properties of undefined (reading 'resolve')

This is because the logic in the try statement changes to 'break' and window.current is immediately deleted in finally.

The problem is reproduced even when only the if_return option of compressor is enabled.
This problem does not occur with terser.

Input code

function Deferred() {
  const deferred = this;
  deferred.promise = new Promise(function (resolve, reject) {
    deferred.resolve = resolve;
    deferred.reject = reject;
  });
}

export async function bug() {
    const s = `next`;
    if (!window[s]) {
        for (window[s] = new Deferred();;)
            if (window.current) await window.current.promise;
            else {
                window.current = window[s];
                try {
                    return await window[s].promise // This line compressed to 'break'. I guess compressor intended jump to 23 line which is looks like same code.
                } finally {
                    delete window.current // Above 'break' makes unintended delete
                }
            }
    }
    return await window[s].promise
}

Config

{
  "jsc": {
    "parser": {
      "syntax": "ecmascript",
      "jsx": false
    },
    "target": "es2022",
    "loose": false,
    "minify": {
      "compress": {
        "arguments": false,
        "arrows": false,
        "booleans": false,
        "booleans_as_integers": false,
        "collapse_vars": false,
        "comparisons": false,
        "computed_props": false,
        "conditionals": false,
        "dead_code": false,
        "directives": false,
        "drop_console": false,
        "drop_debugger": false,
        "evaluate": false,
        "expression": false,
        "hoist_funs": false,
        "hoist_props": false,
        "hoist_vars": false,
        "if_return": true,
        "join_vars": false,
        "keep_classnames": false,
        "keep_fargs": false,
        "keep_fnames": false,
        "keep_infinity": false,
        "loops": false,
        "negate_iife": false,
        "properties": false,
        "reduce_funcs": false,
        "reduce_vars": false,
        "side_effects": false,
        "switches": false,
        "typeofs": false,
        "unsafe": false,
        "unsafe_arrows": false,
        "unsafe_comps": false,
        "unsafe_Function": false,
        "unsafe_math": false,
        "unsafe_symbols": false,
        "unsafe_methods": false,
        "unsafe_proto": false,
        "unsafe_regexp": false,
        "unsafe_undefined": false,
        "unused": false,
        "const_to_let": false,
        "pristine_globals": false,
        "passes": 3
      },
      "mangle": false
    }
  },
  "module": {
    "type": "es6"
  },
  "minify": false,
  "isModule": true
}

Playground link (or link to the minimal reproduction)

https://play.swc.rs/?version=1.3.99&code=H4sIAAAAAAAAA31SPU%2FDMBDd8yuOqamEUgnGiAGJhY2BDSHVTS6tm%2BQc%2BYO0qvLfOePEkAbwENn37r17fk7lqLBSETxhhVpjma7hkgAUioyFcizCA9iDNDkDUynrtGqlQYYIe3gJp7Sa9FKNRjUfeAsaj1jYIPuDP%2BLMH3f5Ne5pX7DfeHRY58mQJHjqlLYgzJkKiAN3bp9OQ4J7w%2BQt4clug7SsIL3pJZWqfzPvU69fldKQRmS80ncieb6OrZNQ6M4Kxy3EtxO9kBbm1SmjfMbGhlO7zEp%2BzansIfrJF71Wn39R8EujdZpmblghPtZmA6%2F8kNBIQk6p7Th7w%2B9rFax2GkW9yuAZ9o6rEeZsJFmkkvuOru188919kOgPsjiAF1Sq9rI1ghGt1y4xWzgcoJIkmuYv9yU2aPE6Cjb9uFP8q4wWoRU1GnAUbQXeclyyPIXv%2FzElwyeFShVWFwMAAA%3D%3D&config=H4sIAAAAAAAAA32VTY7bMAyF9zlF4HUXRQrMogformcQFItylFqiIVKZGIPcfei%2FTNpS3sX8%2BMzokaI%2FDsdjc6W2%2BXn8kJ%2FyMNhMkJ%2FPEqExsb1LpIE2WmpzGLj5ttErTcjbnmAOPRbSsM0d8Kyi0%2FfTaVU0PSLBplhjMaTgx9eaLcYhA9FLTKLyyhIhMf2tX1nGdw2cEXuwaQ8ZSyYkhg6yltZi39uBwNxshUdxLRCqRSZaGJwZMg56QnKBAyaJK9iBdaZFBxoLGVoON1CFUk%2BEieSQNezgXLpu7ve%2FHG62L5Y1Kdzn5shfVuAFA7HxRTVjgTUnFlpxOXiTgUueanIur%2BiKIdVkfwDEhd4SJRtVn%2BYML7NVh7vSkLzML48Kl2FXD5qgE2dNCF6zd7IHMge1ZAZXWpj8bXdwxQwKDgx4L0Oj4vfA7UUty%2BMA6DUijbbqMRZgqhdz5dP92MG%2F5KCsT9qaES1f6pTGeEb1Ym1y4Au6nQRpB2MdZ1kb96HOS3IgAwJOTSmkgunasmE0%2FbxD%2F58QuSjyTtP1eNbXxiATP3fyxxp7PFd2tKn7WgnL1j6sCU1EV2a4fg%2Bmxi9b%2FK35StoW9rNqE%2Bj3ppxu5%2BHxCZo7moVbBgAA

SWC Info output

Operating System:
    Platform: darwin
    Arch: arm64
    Machine Type: arm64
    Version: Darwin Kernel Version 22.5.0: Thu Jun  8 22:22:23 PDT 2023; root:xnu-8796.121.3~7/RELEASE_ARM64_T6020
    CPU: (12 cores)
        Models: Apple M2 Max

Binaries:
    Node: 18.15.0
    npm: 9.5.0
    Yarn: N/A
    pnpm: N/A

Relevant Packages:
    @swc/core: 1.3.99
    @swc/helpers: N/A
    @swc/types: 0.1.5


SWC Config:
    output: N/A
    .swcrc path: N/A

Next.js info:
    output: N/A

Expected behavior

The logic inside the try statement remains.

Actual behavior

The logic inside the try statement is replaced with 'break'.

Version

1.3.99

Additional context

No response

[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.