tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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lgcl-nullish-assignment-operator-non-writeable-strict.js (721B)


      1 'use strict';
      2 // Copyright (c) 2020 Ecma International.  All rights reserved.
      3 // This code is governed by the BSD license found in the LICENSE file.
      4 
      5 /*---
      6 esid: sec-assignment-operators-runtime-semantics-evaluation
      7 description: >
      8    Strict Mode - TypeError is not thrown if the LeftHandSide of a Logical
      9    Assignment operator(??=) is a reference to a data property with the
     10    attribute value {[[Writable]]:false} and PutValue step is not reached.
     11 flags: [onlyStrict]
     12 features: [logical-assignment-operators]
     13 
     14 ---*/
     15 
     16 var obj = {};
     17 Object.defineProperty(obj, "prop", {
     18  value: 0,
     19  writable: false,
     20  enumerable: true,
     21  configurable: true
     22 });
     23 
     24 assert.sameValue(obj.prop ??= 1, 0, "obj.prop");
     25 
     26 reportCompare(0, 0);