I recently received the following question related to debugging:
Debugging takes up a lot of my team’s time. What are some shortcuts, process changes or alternatives that can reduce the need to debug frequently? How can TDD or IDE help?
Figuring out what process changes you might be able to make to reduce the need to debug is what software engineering is all about. That’s a big topic, which can potentially span how you do design, coding, testing, configuration management and project management. That said, I do think I can offer some insights into how test-driven development (TDD) and a good IDE might help.
One of the biggest things TDD offers to the debugging process is more usable code. When you look at well-tested code, where the interface was designed using an evolving suite of tests, it’s often easier to understand what’s happening. In addition, you also have the tests, which not only help document the code’s behavior, but they allow you to make changes with confidence while you’re debugging.
In fact, on past projects where I’ve been one of the programmers, I’ve used my unit tests to help isolate issues — picking a test that’s close to the code I want to isolate and just changing the test again and again until I prove (or disprove) my theory on what the bug is that I’m trying to track down.
The IDE you use can also play a role in how effective your debugging will be. While most IDE’s have basic debugging features built in (breakpoints, ability to view the stack, etc.) some IDE’s have advanced features that allow you to do things like defining complex conditional logic to establish the criteria that will cause the script to halt. This can be good for finding issues that only occur intermittently.
In addition, how your IDE integrates with runtime and static analysis tools can affect your debugging effectiveness. If you’re tracking down a memory leak, depending on the technology you’re working with, you may want to be able to leverage tools that instrument the code for you, or give you line-by-line metrics. If you’re trying to debug a security issue, a static analysis tool that checks for secure coding practices might save you a lot of time.