rspec/rules/S1514/javascript/rule.adoc

``++eval++`` is used to evaluate a string as JavaScript code, and ``++arguments++`` is used to access function arguments through indexed properties. As a consequence, ``++eval++`` and ``++arguments++`` should not be bound or assigned, because doing so would overwrite the original definitions of those two reserved words.

What's more, using either of those two names to assign or bind will generate an error in JavaScript strict mode code.


== Noncompliant Code Example

----
eval = 17; // Noncompliant
arguments++; // Noncompliant
++eval; // Noncompliant
var obj = { set p(arguments) { } }; // Noncompliant
var eval; // Noncompliant
try { } catch (arguments) { } // Noncompliant
function x(eval) { } // Noncompliant
function arguments() { } // Noncompliant
var y = function eval() { }; // Noncompliant
var f = new Function("arguments", "return 17;"); // Noncompliant

function fun() {
  if (arguments.length == 0) { // Compliant
    // do something
  }
}
----


== Compliant Solution

----
result = 17;
args++;
++result;
var obj = { set p(arg) { } };
var result;
try { } catch (args) { }
function x(arg) { }
function args() { }
var y = function fun() { };
var f = new Function("args", "return 17;");

function fun() {
  if (arguments.length == 0) {
    // do something
  }
}
----