ActionMailer::TestHelper

Asserts that the number of emails sent matches the given number.

  def test_emails
    assert_emails 0
    ContactMailer.deliver_contact
    assert_emails 1
    ContactMailer.deliver_contact
    assert_emails 2
  end

If a block is passed, that block should cause the specified number of emails to be sent.

  def test_emails_again
    assert_emails 1 do
      ContactMailer.deliver_contact
    end

    assert_emails 2 do
      ContactMailer.deliver_contact
      ContactMailer.deliver_contact
    end
  end

    # File lib/action_mailer/test_helper.rb, line 27
27:     def assert_emails(number)
28:       if block_given?
29:         original_count = ActionMailer::Base.deliveries.size
30:         yield
31:         new_count = ActionMailer::Base.deliveries.size
32:         assert_equal original_count + number, new_count, "#{number} emails expected, but #{new_count - original_count} were sent"
33:       else
34:         assert_equal number, ActionMailer::Base.deliveries.size
35:       end
36:     end

Assert that no emails have been sent.

  def test_emails
    assert_no_emails
    ContactMailer.deliver_contact
    assert_emails 1
  end

If a block is passed, that block should not cause any emails to be sent.

  def test_emails_again
    assert_no_emails do
      # No emails should be sent from this block
    end
  end

Note: This assertion is simply a shortcut for:

  assert_emails 0

    # File lib/action_mailer/test_helper.rb, line 57
57:     def assert_no_emails(&block)
58:       assert_emails 0, &block
59:     end