How to test jobs which were scheduled (each one min, cron "* * * * *"), but not wait "real" one minute (rufus-scheduler vs virtual time)?

Question

rufus-scheduler lib allows us to schedule tasks https://github.com/jmettraux/rufus-scheduler

require 'rufus-scheduler'

scheduler = Rufus::Scheduler.new

scheduler.cron '* * * * *' do
  # do something every minute
end

In fact, when you want to test your app on top of rufus-scheduler you will need to sleep real 1 min which is too much for typical tests.

For example, in Reactor(Java) they provide StepVerifier.withVirtualTime in order to avoid long-running tests.`:

• https://projectreactor.io/docs/core/release/reference/#_manipulating_time

• https://www.baeldung.com/reactive-streams-step-verifier-test-publisher#3-testing-time-based-publishers

• RxJava - https://medium.com/@vanniktech/taking-control-of-the-time-when-testing-rxjava-code-91b2e5e88bdf

Are there any options for time manipulation within tests for rufus-scheduler or Ruby itself?

Current solution

rufus-scheduler has type in, thus for verification of app skeleton I'm using in=0.001s and sleep 0.4.

Yes, it takes half-of a second in the test but this is much better than 1 minute.

Answer 1

Have a look at

• https://github.com/travisjeffery/timecop
• https://andycroll.com/ruby/replace-timecop-with-rails-time-helpers-in-rspec/

or other "time travel" tools.

I second @spickermann on "only test your own code".