require 'test_helper' class InvoiceMailerTest < ActionMailer::TestCase setup do @invoice = invoices(:one) end def test_delivers_invoice_email assert_equal 1, @invoice.number email = InvoiceMailer.invoice_email(invoice: @invoice, recipient: 'billing@bestnames.test') .deliver_now assert_emails 1 assert_equal ['billing@bestnames.test'], email.to assert_equal 'Invoice no. 1', email.subject assert email.attachments['invoice-1.pdf'] end end