Hey @finscn! We really appreciate you taking the time to report an issue. The collaborators on this project attempt to help as many people as possible, but we're a limited number of volunteers, so it's possible this won't be addressed swiftly.

If you need any help, or just have general Babel or JavaScript questions, we have a vibrant Slack community that typically always has someone willing to help. You can sign-up here for an invite.

For the following case, TypeScript 5.5.3 throws "A 'set' accessor cannot have a return type annotation." as well (playground).

interface Foo {
  set foo (value: number): void
}

If you strongly believe that a setter should allow return type as void, please open a feature request to the TypeScript repo.