ClockworkMocks

This gem provides helpers for integration testing with clockwork. Clockwork provides a cron-like utility for ruby. It works especially well in combination with timecop.

Example Usecase

Image you have a rails app with a clockwork task scheduled every night to check for inactive users and sends them reminders via email. Your clock.rb file would look as follows:

module Clockwork
  every(1.day, 'inactives', at: '00:00') do
    User.inactive.each do
      Mailer.reminder_mail.deliver_later
    end
  end
end

By using ClockworkMocks in combination with RSpec and Timecop, you could test this as follows:

RSpec.describe ... do
  before { ClockworkMocks.reset_rspec(method(:allow), method(:receive)) }
  let!(:user) { create(:user) }

  context 'after 7 days without action' do
    before do
      Timecop.freeze 7.days.from_now
      ClockworkMocks.work
    end
    after { Timecop.return }

    it 'should have sent the user a reminder' do
      expect(ActionMailer::Base.deliveries).not_to be_empty
    end
  end
end

Note that this does not replace proper unit tests, but gives you the possibility to additionally test your system as a whole.

Installation

Add this to your application's Gemfile:

group :test do
  gem 'clockwork-mocks'
end

And then execute:

$ bundle

Or install it yourself as:

$ gem install clockwork-mocks

Usage

Initialization with RSpec

RSpec.describe ... do
  before { ClockworkMocks.reset_rspec(method(:allow), method(:receive), 'path/to/clock.rb') }
end

If you do not pass a clock file path to ClockworkMocks.init_rspec and you are in a rails environment it will assume "#{Rails.root}/clock.rb" by default.

General Initialization

ClockworkMocks.scheduler.handler do |job, time|
  # something
end

ClockworkMocks.scheduler.every(1.day, 'some task', at: '23:00') do
  # something
end

Using this interface, you can use any stub provider to stub Clockwork's methods and call ClockworkMocks.scheduler's methods instead. For example with rspec-mock:

allow(Clockwork).to receive(:handler) do |&block|
  ClockworkMocks.scheduler.handler(&block)
end

allow(Clockwork).to receive(:every) do |interval, name, hash, &block|
  ClockworkMocks.scheduler.every interval, name, hash, &block
end

load 'path/to/clock.rb'

Executing clockwork tasks

At any time you can call ClockworkMocks.work to execute all tasks that are due. This works especially well in combination with timecop (although the latter is not a requirement):

Timecop.freeze(2.days.from_now) do
  ClockworkMocks.work
end

Tasks will be executed in correct order. If enough time passed, tasks will be executed multiple times:

ClockworkMocks.scheduler.every(1.second, 'often') { puts 'often' }
ClockworkMocks.scheduler.every(2.seconds, 'not-so-often') { puts 'not so often' }

Timecop.freeze(3.seconds.from_now) do
  ClockworkMocks.work
end

outputs

often
often
not so often
often

Sidekiq

If you use clockwork to schedule sidekiq jobs but want them to actually execute during integration testing I recommend one of two options:

Use sidekiq's inline mode to execute all jobs immediately during integration testing. This works well if you don't on scheduled jobs or don't care about the execution date.
Use a library like sidekiq-fake-scheduler. This is superior to inline mode in that it respects the dates when the jobs are scheduled so you can test your application more fine-grained. The proposed gem neatly integrates with clockwork-mocks. Disclaimer: I am the creator and maintainer of sidekiq-fake-scheduler.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. 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 tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/dpoetzsch/clockwork-mocks. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

TODO

Basic support for tasks with block
Support for Clockwork.handler
Handle :at parsing correctly
Handle configuration
Handle time zones correctly (currently execution is always timed by UTC)
Handle :if parameter
Handle :skip_first_run parameter

License

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

Code of Conduct

Everyone interacting in the ClockworkMocks project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.

BYWallace/clockwork-mocks