The working basics

test/mailers/user_mailer_test.rb

@@ -0,0 +1,20 @@
+require 'test_helper'
+
+class UserMailerTest < ActionMailer::TestCase
+  test "activation_needed_email" do
+    mail = UserMailer.activation_needed_email
+    assert_equal "Activation needed email", mail.subject
+    assert_equal ["to@example.org"], mail.to
+    assert_equal ["from@example.com"], mail.from
+    assert_match "Hi", mail.body.encoded
+  end
+
+  test "activation_success_email" do
+    mail = UserMailer.activation_success_email
+    assert_equal "Activation success email", mail.subject
+    assert_equal ["to@example.org"], mail.to
+    assert_equal ["from@example.com"], mail.from
+    assert_match "Hi", mail.body.encoded
+  end
+
+end