tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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unscopables-inc-dec.js (1370B)

      1 // Copyright (C) 2017 Mozilla Corporation. All rights reserved.
      2 // This code is governed by the BSD license found in the LICENSE file.
      3 
      4 /*---
      5 esid: sec-object-environment-records-hasbinding-n
      6 description: >
      7  @@unscopables should be looked up exactly once for inc/dec.
      8 info: |
      9  UpdateExpression : LeftHandSideExpression ++
     10  1. Let lhs be the result of evaluating LeftHandSideExpression.
     11 
     12  GetIdentifierReference ( lex, name, strict )
     13  [...]
     14  3. Let exists be ? envRec.HasBinding(name).
     15 
     16  HasBinding ( N )
     17  [...]
     18  6. Let unscopables be ? Get(bindings, @@unscopables).
     19 flags: [noStrict]
     20 features: [Symbol.unscopables]
     21 ---*/
     22 
     23 var unscopablesGetterCalled = 0;
     24 var a, b, flag = true;
     25 with (a = { x: 7 }) {
     26  with (b = { x: 4, get [Symbol.unscopables]() {
     27                      unscopablesGetterCalled++;
     28                      return { x: flag=!flag };
     29                    } }) {
     30    x++;
     31  }
     32 }
     33 
     34 assert.sameValue(unscopablesGetterCalled, 1);
     35 assert.sameValue(a.x, 7);
     36 assert.sameValue(b.x, 5);
     37 
     38 unscopablesGetterCalled = 0;
     39 flag = true;
     40 with (a = { x: 7 }) {
     41  with (b = { x: 4, get [Symbol.unscopables]() {
     42                      unscopablesGetterCalled++;
     43                      return { x: flag=!flag };
     44                    } }) {
     45    x--;
     46  }
     47 }
     48 
     49 assert.sameValue(unscopablesGetterCalled, 1);
     50 assert.sameValue(a.x, 7);
     51 assert.sameValue(b.x, 3);
     52 
     53 reportCompare(0, 0);