How to integrate rubocop with Rake?

Question

rubocop is a code style checker for Ruby. A similar tool to rubocop, Cane, can be integrated with Rake. I prefer rubocop to Cane since rubocop makes checks based on the Ruby Sty

Answer 1

I would recommend shelling out to the rubocop program. It's the simplest solution. Just add this to your Rakefile:

task test: :rubocop

task :rubocop do
  sh 'rubocop'
end

Answer 2

I highly recommend,

require 'rubocop/rake_task'

RuboCop::RakeTask.new(:rubocop) do |t|
  t.options = ['--display-cop-names']
end

This uses the rubocop's own rake tasks and allows you to pass options if you like.

Answer 3

You will probably find https://github.com/yujinakayama/guard-rubocop useful if you use Guard for your RSpec tests. It enables Rubocop to give you instant feedback as soon as you save the file, along with your test results.

Answer 4

You can shell out via Rake with the options you prefer:

  desc 'Run Rubocop with options'
  task rubocop: :environment do
    sh 'bundle exec rubocop -D --format offenses --format progress || true'
  end

I then recommend modifying the default task to include the output. The trick is to clear the task and then add back what you want. Note the need to end with || true so that an error from Rubocop will not prevent the next task from running. Here's what I do, which also uses parallel tests:

task(:default).clear.enhance ['parallel:parallel_prepare', 'parallel:spec',
                              'parallel:features', 'lint:rubocop',
                              'lint:rails_best_practices']

Answer 5

As of version 0.10.0 rubocop contain a custom rake task that you can use. Just put the following in your Rakefile

require 'rubocop/rake_task'

RuboCop::RakeTask.new

Make sure to use upper-case 'R' and 'C' or you will get a NameError.