Web Application DOM Event Dependency Graph Construction Research

Due to the event-driven features and the dynamic of pages' structure and content of Web applications,it's difficult to understand and test Web applications.DOM event dependency graph is important for assisting testers and developers in understanding,debugging,and fixing Web applications.Analyzing DOM event dependencies based on Web application features and improving the efficiency of dependency analysis are significant research content of Web application dependency analysis.In modern Web applications,JavaScript dynamically operates DOM elements to realize the function of Web application,but these operations are likely to trigger DOM event dependence,which increases the difficulty of testing.Static analysis method is a common way to implement DOM event dependency analysis,which is generally composed of three parts.Firstly,source code is analyzed to obtain relevant information of DOM events.Secondly,points-to analysis is used to obtain the object that functions and variables point to in relevant information of DOM events.Finally,based on the relevant information of DOM events after points-to analysis,the dependency relationship between DOM events is deduced according to the rules.However,in the current static analysis methods,the integrity of relevant information of DOM events and the accuracy of points-to analysis cannot be guaranteed,which leads to the inaccuracy of DOM event dependency analysis.In addition,the visible/invisible dependence of DOM events are not considered in the current DOM event dependency analysis,making the test efficiency based on DOM event dependency analysis low.For this purpose,starting from the source code of the Web application,this paper defines the visible and invisible dependencies of DOM events.A new DOM event dependency analysis method is proposed for DOM event dependencies raised by DOM manipulation which based on trigger order,namely the install dependence,the uninstall dependence,the visible dependence and the invisible dependence of DOM events.In order to improve the accuracy and efficiency of DOM event dependency analysis,this method extracts the correlation function when obtaining the relevant information of DOM events,and carries out the corresponding preprocessing,and analyzes the DOM event dependency by means of context-sensitive directional analysis and reverse deduction.On this basis,DOM event dependency graph is built to provide support for Web application testing.In order to verify the effectiveness of the DOM event dependency analysis method,this paper takes six Web applications as experimental objects and compares this method with existing tool JSDEP.Experimental results show that the DOM event dependency analysis method in this paper has higher accuracy and less time cost.Generating test sequences on the DOM event dependency graph in this paper can achieve higher line coverage in less time.Therefore,the DOM event dependency graph constructed in this paper can effectively assist the testing of Web applications.