Basics: No Warnings

Does your code compile with no warnings? Most developers wouldn't dream of checking in code that didn't compiler without errors, but what about warnings? At other companies I've worked at, the code has been full of warning messages. Some of them were relatively harmless (I was working in legacy C code at the time, and as the compiler go better, more warnings were shown). Others were more critical, and really should have been addressed.

In my current job, the main product I work on has around 1 million lines of code, and I'm proud to say that we keep it warning-free. This is no small feat, since we use XML comments, and have the option turned on that generates a warning whenever one is missing from a public or protected member.

Some people would argue that a warning is just that: a warning. If it isn't an error, why bother fixing it? For one, it clutters up the output window and the error list in Visual Studio. It's no fun having to page through several dozen warnings just to find the error(s) you're looking for.

The most important reason, though, is that often, those warnings may be pointing to something more critical that could be wrong with your code. For example, every time we've upgraded the Infragistics library we use, we've had a number of warnings appear because they are planning on deprecating some methods or properties in a future build, and have marked them as such in the current build. Sure, the code still compiles and runs, but maybe it won't in the next build. Infragistics is giving us advance warning that our code may break. We always make it a point to fix those as part of the upgrade process.

Another warning that I've seen a few times is when a developer declares a method in a class with the same signature as one in the base class without realizing it. The compiler warns that you have hidden the base method, and you should either rename it or use the "new" keyword. If you don't clear up this warning, you may be breaking something without even realizing it.

The next time you build the product you're working on, take a look at the build results. If you're getting warning messages, figure out why and get rid of them.