References to destructured exports in namespaces aren't resolvable at runtime

[yseymour]

Describe the bug

Inside a namespace, referring to an exported property in the namespace generally works because it gets emitted as a var binding. However, when the export is defined using destructuring syntax, there are no such bindings and so any references to exports declared that way fail at runtime.

Input code

export namespace cli {
  export const { options, args } = parseCommandLine();
  export function run() {
    const command = args.shift();
  }
}

Config

{
  "jsc": {
    "parser": {
      "syntax": "typescript",
      "tsx": false,
      "decorators": true
    },
    "target": "es2022",
    "loose": false,
    "transform": {
      "legacyDecorator": true,
      "decoratorMetadata": true
    },
    "minify": {
      "compress": false,
      "mangle": false
    }
  },
  "module": {
    "type": "commonjs"
  },
  "minify": false,
  "isModule": true
}

Playground link

https://play.swc.rs/?version=1.3.60&code=H4sIAAAAAAAAA0XMQQqDMBCF4b2neEuF0guUrtx6iWE62oCZhEwEQXL3xkZw9%2BDxf7LHkDKUvFgkFvDqcHSAtIODWsaBELOr8wFKi6HgjUjJZAzek34mp9IPrzubN%2BUzQNq0H%2F4gLotbUoWTetrXzbm1pSs%2FQPhzc48AAAA%3D&config=H4sIAAAAAAAAA22Quw6DMAxF934F8tyhYuzclY%2BwgkFB5CHbSEWIf294hFLRLfZ1zr32dCsK6MTAs5jSMxURWYiPOnVk9Irv1AEdI4lhGxXuWVVZpAZ7oaNXkwmMGliSpDzQKsybDorcki48kvJRljsL%2BhCEflmgjF6awO4cqKcWzfjKJrvH1b0ixRoV%2F4Vw1ttmPFNNcJFJ5LKNQ9%2F2R7CNcttJ4EI9rOJ%2BvuVEy2qJ5oLvBL6T2fGgg5Uqf18Dzh87elJPjwEAAA%3D%3D

Expected behavior

Either emit a var binding for each destructured property, or rewrite the reference to the exported property from args to cli.args (tsc does the latter).

Actual behavior

var cli;
(function(cli) {
    ({ options: cli.options , args: cli.args  } = parseCommandLine());
    function run() {
        const command = args.shift();
    }
    cli.run = run;
})(cli || (cli = {}));

At runtime, ReferenceError: args is not defined

Version

1.3.60

Additional context

Here's the tsc output, for comparison.

var cli;
(function (cli) {
    var _a;
    _a = parseCommandLine(), cli.options = _a.options, cli.args = _a.args;
    function run() {
        const command = cli.args.shift();
    }
    cli.run = run;
})(cli = exports.cli || (exports.cli = {}));

I had a quick look but only found #3073 as a possible related issue, which was quite a while ago.

[yseymour]

Here's the emit for a non-destructured export, for reference:

Input:

export namespace cli {
  export const x = 42;
  export function run() {
    const zzz = x;
  }
}

Output:

var cli;
(function(cli) {
    var x = cli.x = 42;
    function run() {
        const zzz = x;
    }
    cli.run = run;
})(cli || (cli = {}));

[magic-akari]

I will fix this issue in #7202 . But it will take a long time. feel free if anyone can provide a quick fix.

[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.