Cannot assign to private field with loose=true

[ytoune]

Describe the bug

Unable to assign to private field if loose in config is set to true

Input code

class Hoge {
    #hoge: number
    constructor() {
        this.#hoge = 42
    }
}

Config

{
  "jsc": {
    "parser": {
      "syntax": "typescript",
      "tsx": true
    },
    "target": "es2019",
    "loose": true,
    "minify": {
      "compress": false,
      "mangle": false
    }
  },
  "module": {
    "type": "es6"
  },
  "minify": false,
  "isModule": true
}

Playground link

https://play.swc.rs/?version=1.3.21&code=H4sIAAAAAAAAA0vOSSwuVvDIT09VqOblUgAC5Qwgx0ohrzQ3KbUIIpScn1dcUlSaXJJfpKEJUwcCJRmZxXpgDQq2CiZGEIlaXq5aAOAmk3JXAAAA&config=H4sIAAAAAAAAA0WOTQoCMQyF75L1LNSFYO%2FgIULNDJX%2BkWTAUnp321pw9%2FLey5dUeIsFUyEjC%2FFQUqLiBwxoySSWXVbYQKVbyie1rpEP0t4guV2uj576lIR%2B%2BQbBRbeXgbIpZCYRMDt6GRHGw9MaW0eF9DqHUee1ibxD%2BzPWnpPnKs4XviYz9TO2AAAA

Expected behavior

compiled code might look like below

constructor(){
  Object.defineProperty(this, _hoge, {
    writable: true,
    value: void 0
  });
  this[_hoge] = 42;
}

Actual behavior

compiled code

constructor(){
  Object.defineProperty(this, _hoge, {
    writable: true,
    value: void 0
  });
  _classPrivateFieldLooseBase(this, _hoge)[_hoge] = 42;
}

this behaves like

constructor(){
  this[_hoge] = void 0;
  this[_hoge][_hoge] = 42;
  // Uncaught TypeError: Cannot set properties of undefined (setting '__private_0__hoge')
}

Version

1.3.21

Additional context

No response

[ytoune]

this is in version 1.2.155 and above

version 1.2.154

constructor(){
  _classPrivateFieldInit(this, _hoge, {
    writable: true,
    value: void 0
  });
  _classPrivateFieldSet(this, _hoge, 42);
}

[ytoune]

swc/crates/swc_ecma_transforms_base/src/helpers/_class_private_field_loose_base.js

Lines 1 to 7 in 6008995

	function _classPrivateFieldLooseBase(receiver, privateKey) {
	if (!Object.prototype.hasOwnProperty.call(receiver, privateKey)) {
	throw new TypeError("attempted to use private field on non-instance");
	}
	return receiver[privateKey];
	}

swc/packages/swc-helpers/src/_class_private_field_loose_base.mjs

Lines 1 to 7 in 4a27e6f

	export default function _classPrivateFieldBase(receiver, privateKey) {
	if (!Object.prototype.hasOwnProperty.call(receiver, privateKey)) {
	throw new TypeError("attempted to use private field on non-instance");
	}
	return receiver;
	}

[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.