Webpack module bug

foo.js

export default 'foo';

index.js

import foo from './foo';
const bar = 'bar';
let val;

[ val = bar ] = [];
console.log(val);  // "bar"
({ val = bar } = {});
console.log(val);  // "bar"

const [ val2 = foo ] = [];
console.log(val2);  // "foo"
const { val3 = foo } = {};
console.log(val3);  // "foo"

[ val = foo ] = [];  // ReferenceError: foo is not defined
({ val = foo } = {});  // ReferenceError: foo is not defined