12 files changed, 24 insertions, 0 deletions
diff --git a/test/unit/inbound_email/incineration_test.rb b/test/unit/inbound_email/incineration_test.rb
index b46101bcc4..bcaee16de4 100644
--- a/test/unit/inbound_email/incineration_test.rb
+++ b/test/unit/inbound_email/incineration_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative '../../test_helper'
 
 class ActionMailbox::InboundEmail::IncinerationTest < ActiveSupport::TestCase
diff --git a/test/unit/inbound_email/message_id_test.rb b/test/unit/inbound_email/message_id_test.rb
index 1cc3de360e..00e65614ec 100644
--- a/test/unit/inbound_email/message_id_test.rb
+++ b/test/unit/inbound_email/message_id_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative '../../test_helper'
 
 class ActionMailbox::InboundEmail::MessageIdTest < ActiveSupport::TestCase
diff --git a/test/unit/inbound_email_test.rb b/test/unit/inbound_email_test.rb
index 7c42188584..42349bc7b4 100644
--- a/test/unit/inbound_email_test.rb
+++ b/test/unit/inbound_email_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative '../test_helper'
 
 module ActionMailbox
diff --git a/test/unit/mail_ext/address_equality_test.rb b/test/unit/mail_ext/address_equality_test.rb
index 56e9bfa47f..7ea4360b76 100644
--- a/test/unit/mail_ext/address_equality_test.rb
+++ b/test/unit/mail_ext/address_equality_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative '../../test_helper'
 
 module MailExt
diff --git a/test/unit/mail_ext/address_wrapping_test.rb b/test/unit/mail_ext/address_wrapping_test.rb
index 6baa360f3e..a9ae820e26 100644
--- a/test/unit/mail_ext/address_wrapping_test.rb
+++ b/test/unit/mail_ext/address_wrapping_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative '../../test_helper'
 
 module MailExt
diff --git a/test/unit/mail_ext/recipients_test.rb b/test/unit/mail_ext/recipients_test.rb
index e39e1eb89c..4730896354 100644
--- a/test/unit/mail_ext/recipients_test.rb
+++ b/test/unit/mail_ext/recipients_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative '../../test_helper'
 
 module MailExt
diff --git a/test/unit/mailbox/bouncing_test.rb b/test/unit/mailbox/bouncing_test.rb
index 6ac806ba29..ce5de36ff6 100644
--- a/test/unit/mailbox/bouncing_test.rb
+++ b/test/unit/mailbox/bouncing_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative '../../test_helper'
 
 class BouncingWithReplyMailbox < ActionMailbox::Base
diff --git a/test/unit/mailbox/callbacks_test.rb b/test/unit/mailbox/callbacks_test.rb
index 279bf7e574..ae720155cf 100644
--- a/test/unit/mailbox/callbacks_test.rb
+++ b/test/unit/mailbox/callbacks_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative '../../test_helper'
 
 class CallbackMailbox < ActionMailbox::Base
diff --git a/test/unit/mailbox/routing_test.rb b/test/unit/mailbox/routing_test.rb
index f30199b7af..a83fbdacf2 100644
--- a/test/unit/mailbox/routing_test.rb
+++ b/test/unit/mailbox/routing_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative '../../test_helper'
 
 class ApplicationMailbox < ActionMailbox::Base
diff --git a/test/unit/mailbox/state_test.rb b/test/unit/mailbox/state_test.rb
index 32d16ca8fe..78b7d21cd7 100644
--- a/test/unit/mailbox/state_test.rb
+++ b/test/unit/mailbox/state_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative '../../test_helper'
 
 class SuccessfulMailbox < ActionMailbox::Base
diff --git a/test/unit/postfix_relayer_test.rb b/test/unit/postfix_relayer_test.rb
index 9d6e49dee3..b448bf6f9b 100644
--- a/test/unit/postfix_relayer_test.rb
+++ b/test/unit/postfix_relayer_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative '../test_helper'
 
 require 'action_mailbox/postfix_relayer'
diff --git a/test/unit/router_test.rb b/test/unit/router_test.rb
index 70d39ba6a1..ec60fb0889 100644
--- a/test/unit/router_test.rb
+++ b/test/unit/router_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative '../test_helper'
 
 class RootMailbox < ActionMailbox::Base