Fix tests - don't test standard rails features

test/jobs/application_job_test.rb

@@ -37,11 +37,14 @@ class ApplicationJobTest < ActiveJob::TestCase
     end
 
     assert_enqueued_jobs 1 do
-      test_job.perform_later("arg1", "arg2", { key: "value" })
+      test_job.perform_later("arg1", "arg2", { "key" => "value" })
     end
 
-    # Job class name may be nil in test environment, focus on args
-    assert_equal ["arg1", "arg2", { key: "value" }], enqueued_jobs.last[:args]
+    # ActiveJob serializes all hash keys as strings
+    args = enqueued_jobs.last[:args]
+    assert_equal "arg1", args[0]
+    assert_equal "arg2", args[1]
+    assert_equal "value", args[2]["key"]
   end
 
   test "should have default queue configuration" do

test/jobs/invitations_mailer_test.rb

@@ -107,17 +107,15 @@ class InvitationsMailerTest < ActionMailer::TestCase
   end
 
   test "should have proper email headers" do
-    email = @invitation_mail
+    # Deliver the email first to ensure headers are set
+    email = InvitationsMailer.invite_user(@user).deliver_now
 
-    # Test common email headers
+    # Test common email headers (message_id is set on delivery)
     assert_not_nil email.message_id
     assert_not_nil email.date
 
-    # Test content-type
-    if email.html_part
-      assert_includes email.content_type, "text/html"
-    elsif email.text_part
-      assert_includes email.content_type, "text/plain"
-    end
+    # Test content-type - multipart emails contain both text and html parts
+    assert_includes email.content_type, "multipart"
+    assert email.html_part || email.text_part, "Should have html or text part"
   end
 end