Inline-destructuring of method arguments leads to subtle error

[pichfl]

ember-error-route/addon/index.js

Line 31 in 25aa613

serialize({ transition }) {

This line fails if the destructured object is undefined (which can happen when a custom error is thrown).

It gets translated to

    serialize(_ref) {
      let {
        transition
      } = _ref;

which throws

Uncaught TypeError: _ref is undefined

I'm not entirely sure what's going on here. I will post a PR with a failing test.