RSpecWatcher

Provides an instant feedback loop for TDD with RSpec. Automatically runs specs in reaction to changes in files. Inspired by Guard, but unlike Guard, the watcher does not start a new process every time. It only loads the project once and uses code reloading to get changes. Needs to be restarted after changes to files that do not get reloaded (just like you would restart a Rails development server).

Specs that fail are remembered and will be rerun until they pass again. This enables a nearly instant TDD feedbeck loop, because every spec we add will be automatically picked up and run until we add the implementation.

Add rspec-watcher to the Gemfile, only needs to exist in the test group.

group :test do
  gem 'rspec-watcher'
end

Then run bundle install

Disable caching classes in config/environments/test.rb when the watcher is running:

config.cache_classes = ENV['RSPEC_WATCHER'].nil?

Rules for the watcher and other options can be customized, for example in a Rails initializer. Not passing a block to a watch rule will run all specs. The configuration shown here is used by default:

# config/initializers/rspec_watcher.rb

if ENV['RSPEC_WATCHER']
  RSpecWatcher.configure do
    watch 'spec', only: /_spec\.rb\z/ do |modified, added, _removed|
      modified + added
    end

    watch 'spec', ignore: /_spec\.rb\z|examples.txt\z/

    watch 'app', only: /\.rb\z/, ignore: %r{controllers/} do |modified, added, removed|
      (modified + added + removed).map do |path|
        path.sub('app/', 'spec/').sub('.rb', '_spec.rb')
      end
    end

    watch 'app/controllers', only: /\.rb\z/ do |modified, added, removed|
      (modified + added + removed).map do |path|
        path.sub('app/', 'spec/').sub('controllers/', 'requests/').sub('_controller.rb', '_spec.rb')
      end
    end

    watch 'config', only: /routes\.rb\z/
  end
end

Start the watcher with RAILS_ENV=test bundle exec rake rspec_watcher:watch

In order to use the watcher without Rails, path_inferrer and reloader need to be configured. Check lib/rspec-watcher.rb.

After checking out the repo, run bin/setup to install dependencies. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/Sorc96/rspec-watcher.

The gem is available as open source under the terms of the MIT License.