Arrow functions as class properties compile incorrectly

[KidkArolis]

Describe the bug

When using specific browser target to reduce how much compilation is being applied to the code, an edge case surfaces that incorrectly transpiles arrow functions as class properties, losing the correct reference to this. See the attached playground and you'll notice _this.getBar(b) is referencing _this which is not a valid reference.

Input code

class Foo {
  getBar(b) {
    return b * 2
  }

  getFoo = ({ b } = {}) => {
    return this.getBar(b)
  }
}

const f = new Foo()
console.log(f.getFoo({ b: 2 }))

Config

{
    env: {
      targets: '> 0.25% and last 2 versions, not dead, not ie <= 11',
      coreJs: 3,
      mode: 'entry'
    },
    jsc: {
      parser: {
        jsx: true,
        exportDefaultFrom: true
      },
      transform: {}
    }
  }
}

Playground link

https://play.swc.rs/?version=1.2.133&code=H4sIAAAAAAAAA0vOSSwuVnDLz1eo5lJQSE8tcUos0kjSBPMUFIpSS0qL8hSSFLQUjIACtVwQNSDltgoa1UCJWiCjulZTwdYOVUtJRmaxHtw4sF6g7uT8vOIShTSgnrzUcpCtGppgsfycVL2c%2FHSNND2I6SCjrRSMFGo1NQHVZOk3oQAAAA%3D%3D&config=H4sIAAAAAAAAA0WO3QqDMAyFXyUEdidjE9yFbHuDPUSwUTq0lSbKRPrua53Du5Pz85EV39JgveJIQThkJYtT%2BmCN3AwkTbCjYpFqyWqpF44FKoWONVekSlnvvfCeFjhYZ9slkxo%2FjIFFjohc1%2F%2BbMYEGb6ZsrKjLyBvwhvFg7Dsrr72oYUo3u3nbbG8kPD7hci6rE5Az0JMolDBzEOudFOC8gmEyP2UZ7g%2B4XjHGL6hpzCH9AAAA

Expected behavior

this.getBar(b) call should work!

Actual behavior

Error is thrown Uncaught TypeError: _this.getBar is not a function, because _this is not pointing to the class instance.

Version

1.2.133

Additional context

No response

[KidkArolis]

In the provided playground, switching from JavaScript to TypeScript produces correct output!

[Austaras]

There are two layers of bug:
1. compat data(which is directly copied from babel) lacks safari support for optional parameters.
2. swc transform arrow in class field wrongly, which is an extremely rare case since class field is an ES2022 feature while arrow is ES6

see #3268

[williamtetlow]

I believe 2 may be fixed in #3459

[Austaras]

No. This is not related to ts nor decorator

[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.