Add assert_emails and assert_no_emails to test the number of emails delivered. Closes #6479.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@5436 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

2 files changed, 68 insertions, 0 deletions

diff --git a/actionmailer/lib/action_mailer.rb b/actionmailer/lib/action_mailer.rb
index d17772209b..5cf9f4d9a3 100755
--- a/actionmailer/lib/action_mailer.rb
+++ b/actionmailer/lib/action_mailer.rb
@@ -37,6 +37,7 @@ require 'action_mailer/base'
 require 'action_mailer/helpers'
 require 'action_mailer/mail_helper'
 require 'action_mailer/quoting'
+require 'action_mailer/test_helper'
 require 'tmail'
 require 'net/smtp'
 
diff --git a/actionmailer/lib/action_mailer/test_helper.rb b/actionmailer/lib/action_mailer/test_helper.rb
new file mode 100644
index 0000000000..3a1612442f
--- /dev/null
+++ b/actionmailer/lib/action_mailer/test_helper.rb
@@ -0,0 +1,67 @@
+module ActionMailer
+  module 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
+    def assert_emails(number)
+      if block_given?
+        original_count = ActionMailer::Base.deliveries.size
+        yield
+        new_count = ActionMailer::Base.deliveries.size
+        assert_equal original_count + number, new_count, "#{number} emails expected, but #{new_count - original_count} were sent"
+      else
+        assert_equal number, ActionMailer::Base.deliveries.size
+      end
+    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
+    def assert_no_emails(&block)
+      assert_emails 0, &block
+    end
+  end
+end
+
+module Test
+  module Unit
+    class TestCase
+      include ActionMailer::TestHelper
+    end
+  end
+end