Basic implmentation of a variadic helper function/

variadic.js

var variadic = function( fn ) {
  var _slice  = Array.prototype.slice;
  var _length = fn.length;
  
  if ( _length < 1 ) {
    return fn;
  }

  if( _length === 1 ) {
    return function () {
      return fn.call( this, _slice.call( arguments ) );
    };
  }

  return function () {
    var namedArguments    = _slice.call( arguments, 0, _length - 1 );
    var variadicArguments = _slice.call( arguments, _length - 1 );

    return fn.apply( this, namedArguments.concat( [variadicArguments] ) );
  };
};