JSTests/test262/test/language/statements/function/dflt-params-duplicates.js

// This file was procedurally generated from the following sources:
// - src/function-forms/dflt-params-duplicates.case
// - src/function-forms/syntax/func-decl.template
/*---
description: It is a Syntax Error if BoundNames of FormalParameters contains any duplicate elements. (function declaration)
esid: sec-function-definitions-runtime-semantics-instantiatefunctionobject
features: [default-parameters]
flags: [generated]
negative:
  phase: parse
  type: SyntaxError
info: |
    FunctionDeclaration :
        function BindingIdentifier ( FormalParameters ) { FunctionBody }

        [...]
        3. Let F be FunctionCreate(Normal, FormalParameters, FunctionBody,
           scope, strict).
        [...]

    9.2.1 [[Call]] ( thisArgument, argumentsList)

    [...]
    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
    [...]

    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )

    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
    [...]

    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)

    [...]
    23. Let iteratorRecord be Record {[[iterator]]:
        CreateListIterator(argumentsList), [[done]]: false}.
    24. If hasDuplicates is true, then
        [...]
    25. Else,
        b. Let formalStatus be IteratorBindingInitialization for formals with
           iteratorRecord and env as arguments.
    [...]

    14.1.2 Static Semantics: Early Errors

    StrictFormalParameters : FormalParameters

    - It is a Syntax Error if BoundNames of FormalParameters contains any
      duplicate elements.

    FormalParameters : FormalParameterList

    - It is a Syntax Error if IsSimpleParameterList of FormalParameterList is
      false and BoundNames of FormalParameterList contains any duplicate
      elements.

---*/
throw "Test262: This statement should not be evaluated.";

function f(x = 0, x) {
  
}