Testing a service object job with rspec - ruby-on-rails

Question

I have the following job:
class Test::MooJob < ApplicationJob
queue_as :onboarding
def perform
avariable = Test::AragornService.build("a").call
if avariable.status == true
puts "job succeeded"
end
end
end
and the service looks like this:
module Test
class AragornService
def self.build(x)
self.new(x)
end
def initialize(x)
#x = x
end
def call
10.times do
Rails.logger.info #x
end
return ServiceResult.new :status => true, :message => "Service Complete", :data => #x
rescue => e
Bugsnag.notify(e, :context => 'service')
return ServiceResult.new :status => false, :message => "Error occurred - #{e.message}"
end
end
end
I am trying to test it with the following spec:
# bundle exec rspec spec/jobs/test/moo_job_spec.rb
require "rails_helper"
describe Test::MooJob do
subject(:job) { described_class.perform_later }
subject(:job_now) { described_class.perform_now }
let(:key) { "a" }
it 'queues the job' do
ActiveJob::Base.queue_adapter = :test
expect { job }.to have_enqueued_job(described_class)
.on_queue("onboarding")
end
it 'calls the aragorn service once' do
allow(Test::AragornService.new(key)).to receive(:call).and_return(ServiceResult.new(:status => true))
expect_any_instance_of(Test::AragornService).to receive(:call).exactly(1).times
job_now
end
end
Why is it that avariable value keeps returning nil
I get the following error "undefined method `status' for nil:NilClass"
however, when I return a simple boolean,
allow(Test::AragornService.new(key)).to receive(:call).and_return(true)
It sets avariable value to true
here's the ServiceResult class:
class ServiceResult
attr_reader :status, :message, :data, :errors
def initialize(status:, message: nil, data: nil, errors: [])
#status = status
#message = message
#data = data
#errors = errors
end
def success?
status == true
end
def failure?
!success?
end
def has_data?
data.present?
end
def has_errors?
errors.present? && errors.length > 0
end
def to_s
"#{success? ? 'Success!' : 'Failure!'} - #{message} - #{data}"
end
end

Answer 1

Its because you are just setting expections on a unrelated instance of Test::AragornService in your spec:
allow(Test::AragornService.new(key)).to
receive(:call).and_return(ServiceResult.new(:status => true))
This does nothing to effect the instance created by Test::AragornService.build
class Test::MooJob < ApplicationJob
queue_as :onboarding
def perform
avariable = Test::AragornService.build("a").call
if avariable.status == true
puts "job succeeded"
end
end
end
You can solve it by stubbing Test::AragornService.build to return a double:
double = instance_double("Test::AragornService")
allow(double).to receive(:call).and_return(ServiceResult.new(status: true))
# bundle exec rspec spec/jobs/test/moo_job_spec.rb
require "rails_helper"
describe Test::MooJob do
let(:perform_later) { described_class.perform_later }
let(:perform_now ) { described_class.perform_now }
let(:service) { instance_double("Test::AragornService") }
before do
# This injects our double instead when the job calls Test::AragornService.build
allow(Test::AragornService).to receive(:build).and_return(service)
end
it 'queues the job' do
# this should be done in `rails_helper.rb` or `config/environments/test.rb` not in the spec!
ActiveJob::Base.queue_adapter = :test
expect { perform_later }.to have_enqueued_job(described_class)
.on_queue("onboarding")
end
it 'calls the aragorn service once' do
expect(service).to receive(:call).and_return(ServiceResult.new(status: true))
perform_now
end
end