Functional depedency analysis

Developers who have used eclipse cannot miss out the Cntrl+Shift+G combo - the easiest way to find all references to a particular member/method/class in your workspace. Consider a scenario where you are a new guy maintaining a web application written in java. Now, you are about to change a method signature, and you do a Cntl+Shift+G to find all references to the said method (yes, hoping that you are not doing depedency injection / reflection etc). However, a new guy, would want not to screw up any functionality in the application. How would ensure that the functional dependencies are not affected?

I guess..the question is a bit unclear.. lemme rephrase... Say you are changing something functional (an if loop in a business rule or whateva) - this will definetly CHANGE something else in the context of the application.. and at this point you wish there was something (a plugin?) in eclipse, that would tell you - "hey noob..don't change this - it would affect this..." - Now, if you were to create something that does this for eclips开发者_JS百科e (plugin?) - where would you start? (tagging parts of scr code and introducing a depdency tree? etc?)

Perhaps I failed to understand your question, but I think I might have an answer. Take a look at nWire for Java (or PHP). It is a plugin for code exploration. Focusing on a piece of code, the developer can quickly determine where the method is invoked, where the class is used, etc. This makes it easier to understand what you are about to change.

I am the developer of this plugin. If it is not exactly what you are looking for, let me know, I'll be happy to better understand what you are looking for.

Besides: ALT+SHIFT+C is the way to change a method signature. ALT+SHIFT+G "only" finds references, which is helpful of course.

vickirk mentionend the most important aspect here: Without having tests and a good code coverage you aren't able to apply any changes without risking a failing system afterwards.

The book "Working Effectively with Legacy Code" from Robert C Martin explains it nicely: All code, which is not covered by tests, is legacy code. You could draw the conclusion, that before you apply any functional change you need to ensure a sufficient test coverage.

Tagging parts in the source code seems like a bad idea, since these tags need to be additionally maintained, which usually never really happens in projects. :)

What about JDepend?