simplest advice functional mixin

advice.js

// usage
withAdvice.call(targetObject);

var withSomething = function() {
  this.wrap('walk', function() {
    // before
    this.base();
    // after
  });
};

withSomething.call(targetObject);


// implementation
function withAdvice() {

  this.base = function() { };

  this.wrap = function(method, funct) {
    var original = this[method];

    if (typeof original !== 'function')
      return this[method] = funct;

    this[method] = function() {
      var base = this.base;
      this.base = original;
      var result = funct.apply(this, arguments);
      this.base = base;
      return result;
    };
  };
}