Input Code

function foo({param}) {}
console.log(foo.length); // 1

async function bar({param}) {}
console.log(bar.length); // 0 (!)

Babel Configuration (.babelrc, package.json, cli command)

{
  "plugins": [
    "transform-async-to-generator"
  ]
}

Expected Behavior

bar.length should be 1, as foo.length is.

Current Behavior

Function bar is being transformed as a function without any params:

let bar = (() => {
  var _ref = _asyncToGenerator(function* ({ param }) {});

  return function bar() {
    return _ref.apply(this, arguments);
  };
})();

Possible Solution

I guess that's a regression from #4901.

Your Environment