sidekiq_job_spec.rb

require 'rails_helper'

RSpec.describe SendEmailJob, type: :job do
  let(:Mailer) { create(:Mailer) }
  let(:email) { "[email protected]" }
  let(:body) { "Hello World" }

  it 'enqueues itself on default queue' do
    ActiveJob::Base.queue_adapter = :test
    expect { SendEmailJob.perform_async(email, body) }
           .to have_enqueued_job(SendEmailJob).on_queue('default')
  end

  describe '#perform' do
    it 'sends a given mail with to the given id' do
      expect(Mailer).to receive(send).with(body, email)
      SendEmailJob.perform_async(body, email)
    end
  end
end