RuboCop
A Ruby static code analyzer and formatter, based on the community Ruby
... 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).