Add frozen string literal comment to files.

Add frozen string literal comment to files.

diff --git a/app/controllers/discourse_prometheus_alert_receiver/receiver_controller.rb b/app/controllers/discourse_prometheus_alert_receiver/receiver_controller.rb
index bfb27a7..e285bd2 100644
--- a/app/controllers/discourse_prometheus_alert_receiver/receiver_controller.rb
+++ b/app/controllers/discourse_prometheus_alert_receiver/receiver_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'time'
 require 'cgi'
 
diff --git a/app/jobs/concerns/alert_post_mixin.rb b/app/jobs/concerns/alert_post_mixin.rb
index b034294..686b7fc 100644
--- a/app/jobs/concerns/alert_post_mixin.rb
+++ b/app/jobs/concerns/alert_post_mixin.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module AlertPostMixin
   extend ActiveSupport::Concern
 
diff --git a/app/jobs/regular/process_alert.rb b/app/jobs/regular/process_alert.rb
index f14b98f..093717e 100644
--- a/app/jobs/regular/process_alert.rb
+++ b/app/jobs/regular/process_alert.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jobs
   class ProcessAlert < Jobs::Base
     include AlertPostMixin
diff --git a/app/jobs/regular/process_grouped_alerts.rb b/app/jobs/regular/process_grouped_alerts.rb
index ac187d4..0cea0d3 100644
--- a/app/jobs/regular/process_grouped_alerts.rb
+++ b/app/jobs/regular/process_grouped_alerts.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jobs
   class ProcessGroupedAlerts < Jobs::Base
     sidekiq_options retry: false
diff --git a/lib/opsgenie_schedule.rb b/lib/opsgenie_schedule.rb
index 26ad964..905c652 100644
--- a/lib/opsgenie_schedule.rb
+++ b/lib/opsgenie_schedule.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'msgpack'
 
 class OpsgenieSchedule
diff --git a/plugin.rb b/plugin.rb
index 0dae83f..3d77bae 100644
--- a/plugin.rb
+++ b/plugin.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # name: discourse-prometheus-alert-receiver
 # about: Receives a Prometheus webhook and creates a topic in Discourse
 # version: 0.1
diff --git a/spec/integration/discourse_prometheus_alert_receiver/receiver_controller_spec.rb b/spec/integration/discourse_prometheus_alert_receiver/receiver_controller_spec.rb
index 069221b..0f475d9 100644
--- a/spec/integration/discourse_prometheus_alert_receiver/receiver_controller_spec.rb
+++ b/spec/integration/discourse_prometheus_alert_receiver/receiver_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 RSpec.describe DiscoursePrometheusAlertReceiver::ReceiverController do
diff --git a/spec/lib/opsgenie_schedule_spec.rb b/spec/lib/opsgenie_schedule_spec.rb
index f8398af..5f981a9 100644
--- a/spec/lib/opsgenie_schedule_spec.rb
+++ b/spec/lib/opsgenie_schedule_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 RSpec.describe OpsgenieSchedule do
diff --git a/spec/lib/topic_query_spec.rb b/spec/lib/topic_query_spec.rb
index 31ceca1..50739ab 100644
--- a/spec/lib/topic_query_spec.rb
+++ b/spec/lib/topic_query_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 RSpec.describe TopicQuery do
diff --git a/spec/model/category_spec.rb b/spec/model/category_spec.rb
index af295bd..2833ed5 100644
--- a/spec/model/category_spec.rb
+++ b/spec/model/category_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 RSpec.describe Category do
diff --git a/spec/serializers/site_serializer_spec.rb b/spec/serializers/site_serializer_spec.rb
index 81f7cc3..80252f8 100644
--- a/spec/serializers/site_serializer_spec.rb
+++ b/spec/serializers/site_serializer_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 RSpec.describe SiteSerializer do

GitHub sha: 390a2c06