JavaScript Decorator

function decorate (baseFunction, decoratorFunction) {
    return function () {decoratorFunction(baseFunction, arguments);};
}

function a (a) {
    console.log(a);
    return 'OK';
}

function b (baseFunction, baseFunctionArguments) {
    console.log('start');
    baseFunction.apply(null, baseFunctionArguments);
    console.log('b');
    console.log('stop');
}

a = decorate(a, b);

a('a');

function trace (baseFunction, baseFunctionArguments) {
    var result = baseFunction.apply(null, baseFunctionArguments);
    console.log('TRACE: ' + baseFunction.name + ' (' + Array.prototype.slice.call(baseFunctionArguments).join(', ') + ') => ' + result);
    return result;
}

var c = decorate(a, trace);

c('a', 'b', 1, 2, {});