Test an infinite loop in minitest - minitest

Question

I have a job named ActivityJob which fetches an user's github public activities.
class ActivityJob < ActiveJob::Base
queue_as :git
def perform(user)
begin
#fetch github activities for a user using user's auth_token
activities = ActivitiesFetcher.new(user).fetch
# process the retrieved activities.
rescue Github::Error::NotFound
#user is not present. ignore and complete the job.
rescue Github::Error::Unauthorized
#auth token is invalid. re-assign a new token on next sign in
user.auth_token = nil
user.save
# refresh_gh_client gets a new client using a random user's auth_token
user.refresh_gh_client
retry
rescue Github::Error::Forbidden
# Probably hit the Rate-limit, use another token
user.refresh_gh_client
retry
end
end
end
The method refresh_gh_client gets a random user from db and uses its auth_token to create an new gh_client. the new gh_client is assigned to the current user. This is working fine. In test cases, I am using mocha to stub the method calls.
class ActivityJobTest < ActiveJob::TestCase
def setup
super
#user = create :user, github_handle: 'prasadsurase', auth_token: 'somerandomtoken'
#round = create :round, :open
clear_enqueued_jobs
clear_performed_jobs
assert_no_performed_jobs
assert_no_enqueued_jobs
end
test 'perform with Github::Error::Unauthorized exception' do
User.any_instance.expects(:refresh_gh_client).returns(nil)
ActivitiesFetcher.any_instance.expects(:fetch).raises(Github::Error::Unauthorized, {})
ActivityJob.perform_now(#user, 'all', #round)
#user.reload
assert_nil #user.auth_token
end
end
The problem is that the 'retry' in the job calls the ActivitiesFetcher breaking the expectation that it was supposed to be called only once.
:
unexpected invocation: #<AnyInstance:User>.refresh_gh_client()
unsatisfied expectations:
- expected exactly once, invoked twice: # <AnyInstance:User>.refresh_gh_client(any_parameters)
- expected exactly once, invoked twice: #<AnyInstance:ActivitiesFetcher>.fetch

Answer 1

Make an interface for the ActivitiesFetcher behavior you need. You create an implementation of the interface used only for testing that deals with the idiosyncrasies of testing.