IF THERE'S ONE CERTAINTY IN THE LIFE OF A DEVELOPER, IT'S BUGS. AJAX PROGRAMMING ISN'T ROCKET science, but you can still expect the odd moment of pain during development and maybe even in production. Fortunately, there are plenty of techniques, tools, and libraries available to help you isolate problems as they arise. This chapter breaks them into four categories.
The next two patterns are more Ajax-specific. DOM Inspection is about analyzing the dynamic state of the DOM. Traffic Sniffing is about watching traffic between browser and server.