Closure annotation for variadic function

Question

I'm writing code to be compiled by the Google Closure Compiler in advanced compilation mode. In some places in my code I have variadic functions which I'd normally write with an empty argument list. I'd access the passed arguments by inspecting the special variable arguments inside the body.

But how can I explain this to the Closure Compiler using annotations? If I don't do any parameter annotation, it complains that the function expects zero arguments. If I write an annotation @param {...*} (to mean an arbitrary number of arguments of arbitrary type), then it complains since the @param annotation must include the name of the parameter. And if I write @param {...*} arguments then it complains that the named argument does not occur in the list of arguments in the function implementation.

The only way I found to make Google happy is by including a dummy name in the argument list as well, even though that is never used. That in turn might confuse readers and perhaps also some linters. So I would prefer some alternative, if one exists.

/** WARNING - Function f1: called with 3 argument(s).
 *            Function requires at least 0 argument(s) and no more than 0 argument(s).
 * @return {number} */
function f1() { return arguments.length; }

/** WARNING - Bad type annotation. expecting a variable name in a @param tag
 * @param {...*}
 * @return {number} */
function f2() { return arguments.length; }

/** WARNING - parameter arguments does not appear in f3's parameter list
 * @param {...*} arguments
 * @return {number} */
function f3() { return arguments.length; }

/** WARNING - Function f4: called with 3 argument(s).
 *            Function requires at least 0 argument(s) and no more than 0 argument(s).
 * @return {number} */
function f4(/* ... */) { return arguments.length; }

/** This works but seems slightly confusing to me.
 * @param {...*} var_args
 * @return {number} */
function f5(var_args) { return arguments.length; }

window["run"] = function() {
  return f1(1,2,3) + f2(1,2,3) + f3(1,2,3) + f4(1,2,3) + f5(1,2,3);
};

Compile this using

java -jar compiler.jar --compilation_level ADVANCED --warning_level VERBOSE foo.js

Answer 1

"f5" is the expected pattern.

/** 
 * @param {...*} var_args
 * @return {number} 
 */
function f5(var_args) { return arguments.length; }

An alternative is:

/** @type {function(...*):number} */
function f5() { return arguments.length; }