preset-env: Edge support for arrow param destructuring

[benmosher]

Q	A
Fixed Issues?	Fixes #8349
Patch: Bug Fix?	Yes
Major: Breaking Change?	No
Minor: New Feature?	No
Tests Added + Pass?	No tests added (only data changed), all tests passed locally
Documentation PR Link
Any Dependency Changes?	No
License	MIT

Added the as-yet-Edge-unsupported arrow function parameter destructuring as a feature supported by transform-parameters, per compat-table.

[babel-bot]

Build successful! You can test your changes in the REPL here: https://babeljs.io/repl/build/9282/

[benmosher]

FWIW, I published this to npm as @benmosher/babel-preset-env@7.1.1

[existentialism]

@benmosher thanks!

[JSteunou]

@benmosher & @existentialism I think this PR introduced a regression, can you look at #9020 (comment) please ?

[JSteunou]

Moreover Edge 17, 16 handles it (maybe more, I could not go back under)

[JSteunou]

My bad, it supports it only if there are no previous parameters, issue is still valid

This is supported

(({b = 0, c = 3}) => {
  return b === 2 && c === 3;
})({b: 2});

this is not supported

((a, {b = 0, c = 3}) => {
  return a === 1 && b === 2 && c === 3;
})(1, {b: 2});```

[benmosher]

@JSteunou is it possible to do the transpilation in a finer-grained way? AFAICT it's just the one plugin package that handles both fixing this issue but also has the _this = super() bug in #9020. I would think ideally the _this = super() would instead be something that works in Edge (e.g. #9060) but I am not especially Babel-literate 😕 .

[adrienharnay]

Hey, just ran into this. Using @babel/preset-env 7.1.6, and basically it outputs this using esmodules: true:

class User_User extends react_default.a.Component {
  constructor() {
    var _this;

    _this = super(...arguments);

    User_defineProperty(this, "onClick", () => {
      if (!this.props.user) {
        this.props.doSomething();
      }
    });

    User_defineProperty(this, "render", function () {
      let optionalArg = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 'false';
      // this line crashes on Edge 17.1734 (latest at this moment)
      const _this$props = _this.props,
            user = _this$props.user;
    });
  }

  render() {
    const user = this.props.user;
    return react_default.a.createElement("div");
  }
}

Is there any work on this at the moment? Any workaround in the meantime?

Thanks in advance!