1. A method, in a data processing system, for debugging a graphical user interface (GUI) of a computer application code, comprising: detecting, by a debug agent running on a computing device associated with the data processing system, a user interaction with a first renderable object of the GUI during execution of the computer application code; identifying, by a user interface debugger running on the data processing system, one or more second renderable objects of the GUI that are reachable from the first renderable object based on an identity of the first renderable object and a type of the user interaction; applying, by the user interface debugger, one or more compliance rules to the first renderable object and one or more second renderable objects, the compliance rules specifying requirements for at least one relationship between the first renderable object and the one or more second renderable objects; and outputting, by the user interface debugger, results of the application of the one or more compliance rules to the first renderable object and one or more second renderable objects, wherein the one or more compliance rules specify a required relationship between the first renderable object and the one or more second renderable objects with regard to operations performed by, and state of, the one or more second renderable objects in response to the type of the user interaction.