Array methods should not be called on the arguments object itself

• BAD_ARRAY_METHOD_ON_ARGUMENTS
• Error
• High
• No tags

This rule applies when an array method is called on the arguments object itself.

The arguments object is not an array, but an array-like object. It should be converted to a real array before calling an array method. Otherwise, a TypeError exception will be thrown because of the non-existent method.

You can consider using Array.prototype.slice() or ES6 rest parameters to convert the arguments object to a real Array object.

Noncompliant Code Example

function add(x, y) {
  return x + y;
}
function sum() {
  return arguments.reduce(add, 0); // BAD_ARRAY_METHOD_ON_ARGUMENTS alarm because 'reduce()' is an array method.
}

Compliant Code Example

function add(x, y) {
  return x + y;
}
function sum(...args) {
  return args.reduce(add, 0);
}

Version

This rule was introduced in DeepScan 1.32.0.

See

• The arguments object