tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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params-dflt-meth-args-unmapped.js (3361B)

      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-class-definitions-runtime-semantics-evaluation
      6 es6id: 14.5.16
      7 features: [default-parameters]
      8 info: |
      9    ClassExpression : class BindingIdentifieropt ClassTail
     10 
     11    1. If BindingIdentifieropt is not present, let className be undefined.
     12    2. Else, let className be StringValue of BindingIdentifier.
     13    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
     14       with argument className.
     15    [...]
     16 
     17    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
     18 
     19    21. For each ClassElement m in order from methods
     20        a. If IsStatic of m is false, then
     21           i. Let status be the result of performing
     22              PropertyDefinitionEvaluation for m with arguments proto and
     23              false.
     24        [...]
     25 
     26    14.3.8 Runtime Semantics: DefineMethod
     27 
     28    MethodDefinition : PropertyName ( StrictFormalParameters ) { FunctionBody }
     29 
     30    [...]
     31    6. Let closure be FunctionCreate(kind, StrictFormalParameters, FunctionBody,
     32       scope, strict). If functionPrototype was passed as a parameter then pass its
     33       value as the functionPrototype optional argument of FunctionCreate.
     34    [...]
     35 
     36    9.2.1 [[Call]] ( thisArgument, argumentsList)
     37 
     38    [...]
     39    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
     40    [...]
     41 
     42    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
     43 
     44    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
     45    [...]
     46 
     47    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
     48 
     49    [...]
     50    23. Let iteratorRecord be Record {[[iterator]]:
     51        CreateListIterator(argumentsList), [[done]]: false}.
     52    24. If hasDuplicates is true, then
     53        [...]
     54    25. Else,
     55        b. Let formalStatus be IteratorBindingInitialization for formals with
     56           iteratorRecord and env as arguments.
     57    [...]
     58 
     59    14.1.19 Runtime Semantics: IteratorBindingInitialization
     60 
     61    FormalsList : FormalsList , FormalParameter
     62 
     63    1. Let status be the result of performing IteratorBindingInitialization for
     64       FormalsList using iteratorRecord and environment as the arguments.
     65    2. ReturnIfAbrupt(status).
     66    3. Return the result of performing IteratorBindingInitialization for
     67       FormalParameter using iteratorRecord and environment as the arguments. 
     68 ---*/
     69 
     70 var callCount = 0;
     71 var C = class {
     72  method(x, _ = 0) {
     73    assert.sameValue(x, undefined, 'parameter binding value (initial)');
     74    assert.sameValue(
     75      arguments[0], undefined, 'arguments property value (initial)'
     76    );
     77 
     78    arguments[0] = 1;
     79 
     80    assert.sameValue(
     81      x, undefined, 'parameter binding value (after arguments modification)'
     82    );
     83    assert.sameValue(
     84      arguments[0], 1, 'arguments property value (after arguments modification)'
     85    );
     86 
     87    x = 2;
     88 
     89    assert.sameValue(
     90      x, 2, 'parameter binding value (after parameter binding modification)'
     91    );
     92    assert.sameValue(
     93      arguments[0],
     94      1,
     95      'arguments property value (after parameter binding modification)'
     96    );
     97    callCount = callCount + 1;
     98  }
     99 };
    100 
    101 C.prototype.method();
    102 
    103 assert.sameValue(callCount, 1, 'method invoked exactly once');
    104 
    105 reportCompare(0, 0);