tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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params-dflt-meth-args-unmapped.js (3276B)

      1 // Copyright (C) 2016 the V8 project authors. All rights reserved.
      2 // This code is governed by the BSD license found in the LICENSE file.
      3 /*---
      4 description: Referencing the arguments object from a default parameter (class expression method)
      5 esid: sec-runtime-semantics-bindingclassdeclarationevaluation
      6 es6id: 14.5.15
      7 features: [default-parameters]
      8 info: |
      9    ClassDeclaration : class BindingIdentifier ClassTail
     10 
     11    1. Let className be StringValue of BindingIdentifier.
     12    2. Let value be the result of ClassDefinitionEvaluation of ClassTail with
     13       argument className.
     14    [...]
     15 
     16    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
     17 
     18    21. For each ClassElement m in order from methods
     19        a. If IsStatic of m is false, then
     20           i. Let status be the result of performing
     21              PropertyDefinitionEvaluation for m with arguments proto and
     22              false.
     23        [...]
     24 
     25    14.3.8 Runtime Semantics: DefineMethod
     26 
     27    MethodDefinition : PropertyName ( StrictFormalParameters ) { FunctionBody }
     28 
     29    [...]
     30    6. Let closure be FunctionCreate(kind, StrictFormalParameters, FunctionBody,
     31       scope, strict). If functionPrototype was passed as a parameter then pass its
     32       value as the functionPrototype optional argument of FunctionCreate.
     33    [...]
     34 
     35    9.2.1 [[Call]] ( thisArgument, argumentsList)
     36 
     37    [...]
     38    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
     39    [...]
     40 
     41    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
     42 
     43    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
     44    [...]
     45 
     46    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
     47 
     48    [...]
     49    23. Let iteratorRecord be Record {[[iterator]]:
     50        CreateListIterator(argumentsList), [[done]]: false}.
     51    24. If hasDuplicates is true, then
     52        [...]
     53    25. Else,
     54        b. Let formalStatus be IteratorBindingInitialization for formals with
     55           iteratorRecord and env as arguments.
     56    [...]
     57 
     58    14.1.19 Runtime Semantics: IteratorBindingInitialization
     59 
     60    FormalsList : FormalsList , FormalParameter
     61 
     62    1. Let status be the result of performing IteratorBindingInitialization for
     63       FormalsList using iteratorRecord and environment as the arguments.
     64    2. ReturnIfAbrupt(status).
     65    3. Return the result of performing IteratorBindingInitialization for
     66       FormalParameter using iteratorRecord and environment as the arguments. 
     67 ---*/
     68 
     69 var callCount = 0;
     70 class C {
     71  method(x, _ = 0) {
     72    assert.sameValue(x, undefined, 'parameter binding value (initial)');
     73    assert.sameValue(
     74      arguments[0], undefined, 'arguments property value (initial)'
     75    );
     76 
     77    arguments[0] = 1;
     78 
     79    assert.sameValue(
     80      x, undefined, 'parameter binding value (after arguments modification)'
     81    );
     82    assert.sameValue(
     83      arguments[0], 1, 'arguments property value (after arguments modification)'
     84    );
     85 
     86    x = 2;
     87 
     88    assert.sameValue(
     89      x, 2, 'parameter binding value (after parameter binding modification)'
     90    );
     91    assert.sameValue(
     92      arguments[0],
     93      1,
     94      'arguments property value (after parameter binding modification)'
     95    );
     96    callCount = callCount + 1;
     97  }
     98 }
     99 
    100 C.prototype.method();
    101 
    102 assert.sameValue(callCount, 1, 'method invoked exactly once');
    103 
    104 reportCompare(0, 0);