RuboCop

RuboCop is a Ruby static code analyzer (a.k.a. linter) and code formatter. Out of the box it will enforce many of the guidelines outlined in the community Ruby Style Guide. RuboCop packs a lot of features on top of what you’d normally expect from a linter. Works with every major Ruby implementation. Autocorrection of many of the code offenses it detects. Robust code formatting capabilities. Multiple result for matters for both interactive use and for feeding data into other tools. Ability to have different configurations for different parts of your codebase. Ability to disable certain cops only for specific files or parts of files. Extremely flexible configuration that allows you to adapt RuboCop to pretty much every style and preference. It’s easy to extend RuboCop with custom cops and formatters. Many online services use RuboCop internally (e.g. HoundCI, Sider and CodeClimate).