Chefstyle - Version Pinned rubocop and sane defaults for Ruby

Gem Version Build Status

This is an internal style guide for chef ruby projects (chef-client, ohai, mixlib-shellout, mixlib-config, etc).

It is not meant for consumption by cookbooks or for any general purpose uses. Chef Users and Customers Should Generally Not Use This Tool and Should Use Cookstyle. It is not intended for any audience outside of chef core ruby development.

It will conflict with rubocop defaults, cookstyle, finstyle and other ruby style guides entirely by design. The point is that the core chef authors vehemently disagree with them on points of style and this point is generally not up for debate.

It will have many rules that are disabled simply because fixing a project as large as chef-client would be tedious and have little value. It will have other rules that are disabled because chef exposes edge conditions that make them falsely alert. Other rules will be selected based on the biases of the core chef developers which are often violently at odds with the rubocop core developers over ruby style.

Pull requests to this repo will not be accepted without corresponding PRs into at least the chef-client and ohai codebases to clean the code up. PRs will not be accepted that assume unfunded mandates for other people to finish the work. Do not open PRs offering opinions or suggestions without offering to do the work.

The project itself is a derivative of finstyle, but starts with all rules disabled. The active ruleset is in the config/chefstyle.yml file.

How It Works

This library has a direct dependency on one specific version of RuboCop (at a time), and [patches it][patch] to load the [upstream configuration][upstream] and [custom set][config] of rule updates. When a new RuboCop release comes out, this library can rev its pinned version dependency and [re-vendor][rakefile] the upstream configuration to determine if any breaking style or lint rules were added/dropped/reversed/etc.

Installation

Add this line to your application's Gemfile:

gem 'chefstyle'

And then execute:

$ bundle

Or install it yourself as:

$ gem install chefstyle

Usage

Vanilla RuboCop

Run RuboCop as normal, simply add a -r chefstyle option when running:

rubocop -r chefstyle -D --format offenses

chefstyle Command

Use this tool just as you would RuboCop, but invoke the chefstyle binary instead which patches RuboCop to load rules from the chefstyle gem. For example:

chefstyle -D --format offenses

Rake

In a Rakefile, the setup is exactly the same, except you need to require the chefstyle library first:

require "chefstyle"
require "rubocop/rake_task"
RuboCop::RakeTask.new do |task|
  task.options << "--display-cop-names"
end

guard-rubocop

You can use one of two methods. The simplest is to add the -r chefstyle option to the :cli option in your Guardfile:

guard :rubocop, cli: "-r chefstyle" do
  watch(%r{.+\.rb$})
  watch(%r{(?:.+/)?\.rubocop\.yml$}) { |m| File.dirname(m[0]) }
end

Alternatively you could pass the path to Chefstyle's configuration by using the Chefstyle.config method:

require "chefstyle"

guard :rubocop, cli: "--config #{Chefstyle.config}" do
  watch(%r{.+\.rb$})
  watch(%r{(?:.+/)?\.rubocop\.yml$}) { |m| File.dirname(m[0]) }
end

git pre-commit hoooks

In any repo a pre-commit hook can be used in .git/hooks/pre-commit to catch offenses before checkin:

#!/usr/bin/env ruby

changed_files = `git diff --name-only --cached`.split.select { |f| File.extname(f) == ".rb" }

unless changed_files.empty?
  system "chefstyle #{changed_files.join(" ")}"
  unless $?.success?
    puts "\n\nthere was a chefstyle error, please fix before commiting:"
    puts "(chefstyle -a may be able to autofix these issues for you)\n\n"
  end
end
exit $?.to_s[-1].to_i

For whatever $REASON git does not allow easily distributing hooks in the repo itself so each individual user needs to set this up.

.rubocop.yml

As with vanilla RuboCop, any custom settings can still be placed in a .rubocop.yml file in the root of your project.