redeclared-arguments-in-param-expression-eval.js

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// Ensure there's no predefined |arguments| binding.

assertEq("arguments" in this, false);

// Declare |arguments| when no pre-existing (and explicit) |arguments| bindings are present.

function f1(p = eval("var arguments")) {}

assertThrowsInstanceOf(f1, SyntaxError);

// Declare |arguments| when the function body contains an |arguments| var-binding.

function f2(p = eval("var arguments")) {

  var arguments;

assertThrowsInstanceOf(f2, SyntaxError);

// Declare |arguments| when the function body contains an |arguments| function declaration.

//

// <https://tc39.es/ecma262/#sec-functiondeclarationinstantiation> doesn't create the

// implicit |arguments| binding when no parameter expressions are present. This case

// may be special-cased in implementations and therefore should be tested specifically.

function f3(p = eval("var arguments")) {

  function arguments() {}

assertThrowsInstanceOf(f3, SyntaxError);

// Declare |arguments| when the function body contains an |arguments| lexical binding.

//

// <https://tc39.es/ecma262/#sec-functiondeclarationinstantiation> doesn't create the

// implicit |arguments| binding when no parameter expressions are present. This case

// may be special-cased in implementations and therefore should be tested specifically.

function f4(p = eval("var arguments")) {

  let arguments;

assertThrowsInstanceOf(f4, SyntaxError);

// Declare |arguments| when a following parameter is named |arguments|.

function f5(p = eval("var arguments"), arguments) {}

assertThrowsInstanceOf(f5, SyntaxError);

// Declare |arguments| when a preceding parameter is named |arguments|.

function f6(arguments, p = eval("var arguments")) {}

assertThrowsInstanceOf(f6, SyntaxError);

// Repeat the same kind of tests for arrow function.

// Declare |arguments| when no pre-existing |arguments| bindings are present.

var a1 = (p = eval("var arguments = 'param'")) => {

  assertEq(arguments, "param");

};

a1();

// Declare |arguments| when the function body contains an |arguments| var-binding.

var a2 = (p = eval("var arguments = 'param'"), q = () => arguments) => {

  var arguments = "local";

  assertEq(arguments, "local");

  assertEq(q(), "param");

};

a2();

// Declare |arguments| when the function body contains an |arguments| function declaration.

var a3 = (p = eval("var arguments = 'param'"), q = () => arguments) => {

  function arguments() {}

  assertEq(typeof arguments, "function");

  assertEq(q(), "param");

};

a3();

// Declare |arguments| when the function body contains an |arguments| lexical binding.

var a4 = (p = eval("var arguments = 'param'"), q = () => arguments) => {

  let arguments = "local";

  assertEq(arguments, "local");

  assertEq(q(), "param");

};

a4();

// Declare |arguments| when a following parameter is named |arguments|.

var a5 = (p = eval("var arguments"), arguments) => {};

assertThrowsInstanceOf(a5, SyntaxError);

// Declare |arguments| when a preceding parameter is named |arguments|.

var a6 = (arguments, p = eval("var arguments")) => {};

assertThrowsInstanceOf(a6, SyntaxError);

// None of the direct eval calls introduced a global |arguments| binding.

assertEq("arguments" in this, false);

if (typeof reportCompare === "function")

  reportCompare(true, true);