$.fn.hasEvent

gistfile1.js

  $.fn.hasEvent = function(event, fn) {
    if (!event) { return this; }
    var has = {
          event: false,
          namespace: false,
          handler: false
        },
        events = this.data("events"),
        namespace = event.split(".");
    event = namespace.shift();
    namespace = namespace.join(".");
    if (events) {
      if (!namespace) { has.namespace = true; }
      if (!fn) { has.handler = true; }
      if (event in events) {
        $.each(events[event], function(i, v) {
          if (namespace) {
            if (namespace === v.namespace && event === v.type) {
              has.namespace = true;
              has.event = true;
              if (fn && fn === v.handler) { has.handler = true; }
            }
          }
          else {
            if (event === v.type) {
              has.event = true;
              if (fn && fn === v.handler) { has.handler = true; }
            }
          }
        });
      }
    }
    return has.event && has.namespace && has.handler;
  };

  Examples: http://jsbin.com/ehezux/2