3 files changed, 84 insertions, 0 deletions
diff --git a/actionmailer/test/mailers/params_mailer.rb b/actionmailer/test/mailers/params_mailer.rb
new file mode 100644
index 0000000000..4c0fae6d91
--- /dev/null
+++ b/actionmailer/test/mailers/params_mailer.rb
@@ -0,0 +1,11 @@
+class ParamsMailer < ActionMailer::Base
+  before_action { @inviter, @invitee = params[:inviter], params[:invitee] }
+
+  default to: Proc.new { @invitee }, from: -> { @inviter }
+
+  def invitation
+    mail(subject: "Welcome to the project!") do |format|
+      format.text { render plain: "So says #{@inviter}" }
+    end
+  end
+end
diff --git a/actionmailer/test/parameterized_test.rb b/actionmailer/test/parameterized_test.rb
new file mode 100644
index 0000000000..914ed12312
--- /dev/null
+++ b/actionmailer/test/parameterized_test.rb
@@ -0,0 +1,55 @@
+require "abstract_unit"
+require "active_job"
+require "mailers/params_mailer"
+
+class ParameterizedTest < ActiveSupport::TestCase
+  include ActiveJob::TestHelper
+
+  setup do
+    @previous_logger = ActiveJob::Base.logger
+    ActiveJob::Base.logger = Logger.new(nil)
+
+    @previous_delivery_method = ActionMailer::Base.delivery_method
+    ActionMailer::Base.delivery_method = :test
+
+    @previous_deliver_later_queue_name = ActionMailer::Base.deliver_later_queue_name
+    ActionMailer::Base.deliver_later_queue_name = :test_queue
+    ActionMailer::Base.delivery_method = :test
+
+    @mail = ParamsMailer.with(inviter: "david@basecamp.com", invitee: "jason@basecamp.com").invitation
+  end
+
+  teardown do
+    ActiveJob::Base.logger = @previous_logger
+    ParamsMailer.deliveries.clear
+
+    ActionMailer::Base.delivery_method = @previous_delivery_method
+    ActionMailer::Base.deliver_later_queue_name = @previous_deliver_later_queue_name
+  end
+
+  test "parameterized headers" do
+    assert_equal(["jason@basecamp.com"], @mail.to)
+    assert_equal(["david@basecamp.com"], @mail.from)
+    assert_equal("So says david@basecamp.com", @mail.body.encoded)
+  end
+
+  test "enqueue the email with params" do
+    assert_performed_with(job: ActionMailer::Parameterized::DeliveryJob, args: ["ParamsMailer", "invitation", "deliver_now", { inviter: "david@basecamp.com", invitee: "jason@basecamp.com" } ]) do
+      @mail.deliver_later
+    end
+  end
+
+  test "respond_to?" do
+    mailer = ParamsMailer.with(inviter: "david@basecamp.com", invitee: "jason@basecamp.com")
+
+    assert_respond_to mailer, :invitation
+    assert_not_respond_to mailer, :anything
+
+    invitation = mailer.method(:invitation)
+    assert_equal Method, invitation.class
+
+    assert_raises(NameError) do
+      invitation = mailer.method(:anything)
+    end
+  end
+end
diff --git a/actionmailer/test/test_helper_test.rb b/actionmailer/test/test_helper_test.rb
index 31ac5a5211..876e9b0634 100644
--- a/actionmailer/test/test_helper_test.rb
+++ b/actionmailer/test/test_helper_test.rb
@@ -143,6 +143,16 @@ class TestHelperMailerTest < ActionMailer::TestCase
     end
   end
 
+  def test_assert_enqueued_parameterized_emails
+    assert_nothing_raised do
+      assert_enqueued_emails 1 do
+        silence_stream($stdout) do
+          TestHelperMailer.with(a: 1).test.deliver_later
+        end
+      end
+    end
+  end
+
   def test_assert_enqueued_emails_too_few_sent
     error = assert_raise ActiveSupport::TestCase::Assertion do
       assert_enqueued_emails 2 do
@@ -176,6 +186,14 @@ class TestHelperMailerTest < ActionMailer::TestCase
     end
   end
 
+  def test_assert_no_enqueued_parameterized_emails
+    assert_nothing_raised do
+      assert_no_enqueued_emails do
+        TestHelperMailer.with(a: 1).test.deliver_now
+      end
+    end
+  end
+
   def test_assert_no_enqueued_emails_failure
     error = assert_raise ActiveSupport::TestCase::Assertion do
       assert_no_enqueued_emails do