Why is this an issue?

In JavaScript, arguments is a built-in array-like object automatically available within the scope of all non-arrow functions. It allows you to access the arguments the function was called with, even if the number of arguments passed during the function call does not match the number declared in the function signature. arguments has entries for each argument, with the first entry’s index at 0.

The arguments object has two deprecated properties called arguments.caller and arguments.callee, which were used to refer to functions involved in the function invocation chain:

• The arguments.callee property contains the currently executing function that the arguments belong to.
• The arguments.caller property returns the function that invoked the currently executing function. It was replaced by Function.prototype.caller, which provides the same functionality.

Both arguments.caller and arguments.callee are non-standard, deprecated, and leak stack information, which poses security risks and severely limits the possibility of optimizations.

Accessing arguments.callee, Function.prototype.caller and Function.prototype.arguments in strict mode will throw a TypeError.

function whoCalled() {
   if (arguments.caller == null)   //Noncompliant
      console.log('I was called from the global scope.');
   else
      console.log(arguments.caller + ' called me!');  // Noncompliant

  console.log(whoCalled.caller);  // Noncompliant
  console.log(whoCalled.arguments);  // Noncompliant
}

Resources

Documentation

• MDN web docs - The arguments object
• MDN web docs - arguments.callee
• MDN web docs - Function.prototype.caller
• MDN web docs - Function.prototype.arguments
• MDN web docs - ReferenceError: deprecated caller or arguments usage