Code Reviews: Before You Even Run The Code

I do a lot of code reviewing, both in my day job as principal developer and also as an open source maintainer. Sometimes it seems like I read more code than I write! Is that a problem? I'm tempted to say that it isn't. To be a good writer, you must be well-read; I believe that to be a good developer, you need to be code-omnivorous and read as much of other people's code as possible. Code reviews are like little chapters of someone else's code to dip into.

Over time I've developed some particular processes that I find helpful when reviewing code. In particular, I often surprise people at how much review I do before I run the code. Sometimes I grab the branch so that I can use my local diff tools, but I don't actually execute code until I've established some basic facts. This post is a little insight into what's happening in this not-running-the-code-yet zone. Continue reading