object-rest-proxy-get-not-called-on-dontenum-keys.js

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// Copyright (C) 2021 Alexey Shvayka. All rights reserved.

// This code is governed by the BSD license found in the LICENSE file.

/*---

esid: sec-destructuring-binding-patterns-runtime-semantics-restbindinginitialization

description: >

  Proxy's "get" trap is not invoked for non-enumerable keys.

info: |

  BindingRestProperty : ... BindingIdentifier

  [...]

  3. Perform ? CopyDataProperties(restObj, value, excludedNames).

  CopyDataProperties ( target, source, excludedItems )

  [...]

  5. Let keys be ? from.[[OwnPropertyKeys]]().

  6. For each element nextKey of keys in List order, do

    [...]

    c. If excluded is false, then

      i. Let desc be ? from.[[GetOwnProperty]](nextKey).

      ii. If desc is not undefined and desc.[[Enumerable]] is true, then

        1. Let propValue be ? Get(from, nextKey).

        2. Perform ! CreateDataPropertyOrThrow(target, nextKey, propValue).

  [[OwnPropertyKeys]] ( )

  [...]

  7. Let trapResultArray be ? Call(trap, handler, « target »).

  8. Let trapResult be ? CreateListFromArrayLike(trapResultArray, « String, Symbol »).

  [...]

  23. Return trapResult.

features: [object-rest, destructuring-binding, Proxy, Symbol]

includes: [compareArray.js, propertyHelper.js]

---*/

var VALUE_GOPD = "VALUE_GOPD";

var VALUE_GET = "VALUE_GET";

var dontEnumSymbol = Symbol("dont_enum_symbol");

var enumerableSymbol = Symbol("enumerable_symbol");

var dontEnumKeys = [dontEnumSymbol, "dontEnumString", "0"];

var enumerableKeys = [enumerableSymbol, "enumerableString", "1"];

var ownKeysResult = [...dontEnumKeys, ...enumerableKeys];

var getOwnKeys = [];

var getKeys = [];

var proxy = new Proxy({}, {

  getOwnPropertyDescriptor: function(_target, key) {

    getOwnKeys.push(key);

    var isEnumerable = enumerableKeys.indexOf(key) !== -1;

    return {value: VALUE_GOPD, writable: false, enumerable: isEnumerable, configurable: true};

},

  get: function(_target, key) {

    getKeys.push(key);

    return VALUE_GET;

},

  ownKeys: function() {

    return ownKeysResult;

},

});

var {...rest} = proxy;

assert.compareArray(getOwnKeys, ownKeysResult);

assert.compareArray(getKeys, enumerableKeys);

verifyProperty(rest, enumerableSymbol, {value: VALUE_GET, writable: true, enumerable: true, configurable: true});

verifyProperty(rest, "enumerableString", {value: VALUE_GET, writable: true, enumerable: true, configurable: true});

verifyProperty(rest, "1", {value: VALUE_GET, writable: true, enumerable: true, configurable: true});

reportCompare(0, 0);