Test the number of emails enqueued?

Question

We can check enqueued_jobs.length, provided that email is the only possible type of background job.

it 'sends exactly one, particular email' do
  expect { post :create }.to(
    # First, we can check about the particular email we care about.
    have_enqueued_mail(MyMailer, :my_particular_email)
  )

  # But we also have to check that no other email was sent.
  expect(ActiveJob::Base.queue_adapter.enqueued_jobs.length).to eq(1)
end

Is there a better way to assert that:

1. MyMailer.my_particular_email was enqueued,
2. no other email was enqueued,
3. and we don't care if other, non-email background jobs were enqueued

Answer 1

# first filter MyMailer job 
my_mail_jobs = ActiveJob::Base.queue_adapter.enqueued_jobs.select { |job|
  job[:job] == SendEmailsJob &&
  job[:args][0] == "MyMailer"
}
# check only once
expect(my_mail_jobs.length).to eq(1) 
# and that send to your particular email not other email
expect(my_mail_jobs.first[:args]).to include("your particular email")