bug: exception with destructuring assignment with private fields

[dnalborczyk]

Bug Report

Current Behavior
Invalid destructuring assignment target exception with destructuring assignment with private fields

Input Code

• REPL

class Foo {
  #client

  constructor(props) {
    ;({ client: this.#client } = props) // throws: Invalid destructuring assignment target
  }
}

transpiles to (excerpt):

({
  client: _classPrivateFieldGet(this, _client)  // notice the getter
} = props);

Environment

• Babel version: v7.2.2

update:

I suppose it would need to use _classPrivateFieldSet as well as transpile the ES2015 destructuring assignment? unless destructuring assignments work with a function call ... which I don't think it does?

var client = props.client
_classPrivateFieldSet(this, _client, client);

for what it's worth: works in node --harmony v11.6.0

[babel-bot]

Hey @dnalborczyk! 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.

[nicolo-ribaudo]

We should transpile it by moving the private assignment after the destructuring.

[dnalborczyk]

then you'd need to rename the instance private field inside the destructuring to local scope as well I suppose?

({ client: this.#client } = props)

becomes something like ...

var _client
({ client: _client } = props)
_classPrivateFieldSet(this, _client, client)

[nicolo-ribaudo]

Yes 👍