Every year, Jetbrains are kind enough to donate an OSS license for IntelliJ to the Selenium project. As part of that process, they’ve asked that we review the product and (kudos to them!) have been clear that they hope we’re open and honest. So, I’ll be open and honest.
I’ve been using Java since the (very) late 90s, and have been using IntelliJ off-and-on since 2003 or so. In the intervening just-over-a-decade, what started as a tool that crossed the Rubicon of “being able to do refactoring” has matured. It has literally changed the way I write code: I now use the “Introduce Variable” refactoring to avoid needing to do initial assignments of values to variables as a matter of course. Indeed, with IntelliJ, I frequently stop thinking about the programming language and start thinking about the structure of the solution. Its refactorings make exploring large scale changes easy and entirely reliable, and once the restructurings are complete, I can jump to symbols with ease.
Code exploration is aided by the simple and quick ways IntelliJ can find usages, and it’s simple to find unused code as method declarations get highlighted in a different shade to used ones. The integrated debugger is sufficiently capable that, coupled with unit tests, it’s normally pretty easy to figure out why some odd behaviour is happening. And, speaking of unit tests, the UI is clear and (I find) intuitive and easy to use.
It’s not all wonder and joy. On large, multi-module codebases, IntelliJ seems to spend too long building caches. Activity Monitor on the Mac suggests it’s doing this in a single threaded manner, which is wasteful on a multicored machine. Switching away from IJ, doing something on the command line involving source control and then switching back is a sure-fire way to make it rebuild the caches, making it unresponsive. Extending IntelliJ by writing plugins is a black art — the documentation is scattered and appears out of date, making getting started on writing one hard.
Overall, though, I love IntelliJ. On the Selenium project, it’s the IDE of choice, and I’ve been incredibly productive in it. Thank you, Jetbrains, for a wonderful tool.