legacy-output.js

// input
@decorator class Bizz {
  @dec m1() {};
  @bar @foo.bar(baz) m2() {};
  @dec static 3 () {};
}

// output
function _applyDecoratedDescriptor(target, property, decorators, descriptor, context) {
  var desc = {};
  Object['ke' + 'ys'](descriptor).forEach(function (key) {
    desc[key] = descriptor[key];
  });
  desc.enumerable = !!desc.enumerable;
  desc.configurable = !!desc.configurable;

  if ('value' in desc || desc.initializer) {
    desc.writable = true;
  }

  desc = decorators.slice().reverse().reduce(function (desc, decorator) {
    return decorator(target, property, desc) || desc;
  }, desc);

  if (context && desc.initializer !== void 0) {
    desc.value = desc.initializer ? desc.initializer.call(context) : void 0;
    desc.initializer = undefined;
  }

  if (desc.initializer === void 0) {
    Object['define' + 'Property'](target, property, desc);
    desc = null;
  }

  return desc;
}

let Bizz = (_dec = foo.bar(baz), decorator(_class = (_class2 = class Bizz {
  m1() {}m2() {}static 3() {}
}, (_applyDecoratedDescriptor(_class2.prototype, "m1", [dec], Object.getOwnPropertyDescriptor(_class2.prototype, "m1"), _class2.prototype), _applyDecoratedDescriptor(_class2.prototype, "m2", [bar, _dec], Object.getOwnPropertyDescriptor(_class2.prototype, "m2"), _class2.prototype), _applyDecoratedDescriptor(_class2, 3, [dec], Object.getOwnPropertyDescriptor(_class2, 3), _class2)), _class2)) || _class);