bizarguments.js

function abc() {
  return def();
}
function def() {
  return abc.arguments[0] * 2;
}

abc(50); // >> 100

// so that's weird enough but:

bizarguments2.js

function foo(arg) {
  bar();
  console.log(arg);
}

function bar() {
  foo.arguments[0] = "lol";
}

foo("hello") // prints "hello"

// alright, so you can't edit the arguments up the stack

bizarguments3.js

function foo(arg) {
  bar();
  // this line is the only thing that changes:
  console.log(arg, arguments[0]);
}

function bar() {
  foo.arguments[0] = "lol";
}

foo("hello") // prints "lol" "lol"

// wait what
// wait what twice

bizarguments4.js

function foo(arg) {
  bar();
  arguments;
  console.log(arg);
}

function bar() {
  foo.arguments[0] = "lol";
}

foo("hello") // prints "lol"

// peeking at arguments updates `arg` value