During development and testing we don’t want to accidentally send emails to the real world. The delivery method for these two envs is set to :test.

In order to assert that a mailer sent a message, we can look at Hanami::Mailer.deliveries. It’s an array of messages that the framework pretended to deliver during a test. Please make sure to clear them in testing setup.

# spec/bookshelf/mailers/welcome_spec.rb
RSpec.describe Mailers::Welcome do
  before { Hanami::Mailer.deliveries.clear }
  let(:user) { ... }
  it "delivers welcome email" do
    Mailers::Welcome.deliver(user: user)
    mail = Hanami::Mailer.deliveries.last
    expect(mail.to).to           eq([user.email])
    expect(mail.body.encoded).to eq("Hello, #{ user.name }")
  end
end