Role models are important.

RuboCop is a Ruby static code analyzer (a.k.a. linter) and codeformatter. Out of the box it will enforce many of the guidelinesoutlined in the community Ruby Style Guide.

RuboCop packs a lot of features on top of what youd normally expect from alinter:

Works with every major Ruby implementation

Auto-correction of many of the code offenses it detects

Robust code formatting capabilities

Multiple result formatters for both interactive use and for feeding data into other tools

Ability to have different configuration 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

Its easy to extend RuboCop with custom cops and formatters

A vast number of ready-made extensions (e.g. rubocop-rails, rubocop-rspec, rubocop-performance and rubocop-minitest)

Wide editor/IDE support

Many online services use RuboCop internally (e.g. HoundCI, Sider and CodeClimate)

Best logo/stickers ever

The project is closely tied to several efforts to document and promote the best practices of the Ruby community:

Ruby Style Guide

Rails Style Guide

RSpec Style Guide

Minitest Style Guide

A long-term goal of RuboCop (and its core extensions) is to cover with cops all the guidelines from the community style guides.

Early on RuboCop aimed to be an opinionated linter/formatter that adhered very closely to the Ruby Style Guide (think gofmt and the like).In those days cops supported just a single style and you couldnt even turn individual cops off. Eventually, we realizedthat in the Ruby community there were some many competing styles and preferences that it was going to be reallychallenging to find one set of defaults that makes everyone happy. Part of this was Rubys own culture and philosophy,part was the lack of common standards for almost 20 years. Its hard to undo any of those, but its also not really necessary.

The early feedback we got lead us to adopt of philosophy of (extreme) configurability and flexibility, and trying to account for every common styleof programming in Ruby. While we still believe that theres a lot of merit to just sticking to the communitystyle guides, we acknowledge that Ruby is all about diversity and doing things the way that makes you happy. Whateverstyle preferences you have RuboCop is there for you. Thats our promises and our guarantee. Within the subjective limits of sanity that is.

So, what to do next? While you can peruse the documentation in whatever way youd like, here area few recommendations:

See "Basic Usage" to get yourself familiar with RuboCopscapabilities.

Adjust RuboCop to your style/preferences. RuboCop is an extremely flexible tool and most aspects of its behaviorcan be tweaked via various configurationoptions. See "Configuration" for more details.

See "Versioning" for information about RuboCop versioning,updates, and the process of introducing new cops.

Explore the existing extensions.