decorator.js

decorate.js

pkg = {};

pkg.foo = function(a, b, c) {
    alert(a + ' ' + b + ' ' + c);
}

pkg.bar = function(a, b) {
    alert(a + ' ' + b + ' ');
}

decorateMethods(pkg, ['foo', 'bar'])

function decorateMethods(object, methods) {
    for(var i = 0, l = methods.length; i < l; i++) {
        object[methods[i]] = reverseArguments(object[methods[i]], object);
    } 
}

function reverseArguments(fn, thisValue) {
    return function() {
        var args = [];
    
        for(var i = 0, l = arguments.length; i < l; i++) {
            args[i] = arguments[l - i - 1];
        }
    
        fn.apply(thisValue, args);        
    }
}

pkg.foo(1, 2, 3); // "3 2 1"