src/dstr-binding/obj-ptrn-prop-obj.case

// Copyright (C) 2016 the V8 project authors. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
template: default
desc: Object binding pattern with "nested" object binding pattern not using initializer
info: |
    13.3.3.7 Runtime Semantics: KeyedBindingInitialization

    [...]
    3. If Initializer is present and v is undefined, then
       [...]
    4. Return the result of performing BindingInitialization for BindingPattern
       passing v and environment as arguments.
---*/

//- elems
{ w: { x, y, z } = { x: 4, y: 5, z: 6 } }
//- vals
{ w: { x: undefined, z: 7 } }
//- body
assert.sameValue(x, undefined);
assert.sameValue(y, undefined);
assert.sameValue(z, 7);

assert.throws(ReferenceError, function() {
  w;
});