Add frozen string literal comment to files.

Add frozen string literal comment to files.

diff --git a/bin/collector b/bin/collector
index 307abe3..d456edb 100755
--- a/bin/collector
+++ b/bin/collector
@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
 
 version = File.read(File.expand_path("../../prometheus_exporter_version", __FILE__)).strip
 spec_file = File.expand_path("../../gems/#{RUBY_VERSION}/specifications/prometheus_exporter-#{version}.gemspec", __FILE__)
diff --git a/lib/demon.rb b/lib/demon.rb
index b28ae16..e47e7f7 100644
--- a/lib/demon.rb
+++ b/lib/demon.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_dependency 'demon/base'
 
 class DiscoursePrometheus::Demon < Demon::Base
diff --git a/lib/internal_metric/custom.rb b/lib/internal_metric/custom.rb
index 56081ef..dae1afe 100644
--- a/lib/internal_metric/custom.rb
+++ b/lib/internal_metric/custom.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiscoursePrometheus::InternalMetric
   class Custom < Base
     attribute :name , :labels, :description, :value, :type
diff --git a/lib/internal_metric/job.rb b/lib/internal_metric/job.rb
index 0543075..9c60242 100644
--- a/lib/internal_metric/job.rb
+++ b/lib/internal_metric/job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiscoursePrometheus::InternalMetric
   class Job < Base
     attribute :job_name, :scheduled, :duration
diff --git a/lib/reporter/global.rb b/lib/reporter/global.rb
index ff33229..2040e31 100644
--- a/lib/reporter/global.rb
+++ b/lib/reporter/global.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiscoursePrometheus::Reporter
   class Global
 
diff --git a/lib/reporter/process.rb b/lib/reporter/process.rb
index d94c883..81395f7 100644
--- a/lib/reporter/process.rb
+++ b/lib/reporter/process.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # collects stats from currently running process
 module DiscoursePrometheus::Reporter
   class Process
diff --git a/plugin.rb b/plugin.rb
index 06e65cd..298150c 100644
--- a/plugin.rb
+++ b/plugin.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # name: discourse-prometheus
 # about: prometheus data collector for discourse
 # version: 0.1
diff --git a/spec/lib/collector_spec.rb b/spec/lib/collector_spec.rb
index 912cc4a..86546a8 100644
--- a/spec/lib/collector_spec.rb
+++ b/spec/lib/collector_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 require 'prometheus_exporter/server'
 require_relative '../../lib/collector'
diff --git a/spec/lib/internal_metric/base_spec.rb b/spec/lib/internal_metric/base_spec.rb
index 02446af..6e93fca 100644
--- a/spec/lib/internal_metric/base_spec.rb
+++ b/spec/lib/internal_metric/base_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 module DiscoursePrometheus::InternalMetric
diff --git a/spec/lib/internal_metric/custom_spec.rb b/spec/lib/internal_metric/custom_spec.rb
index 41866c1..b4c155e 100644
--- a/spec/lib/internal_metric/custom_spec.rb
+++ b/spec/lib/internal_metric/custom_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 module DiscoursePrometheus::InternalMetric
diff --git a/spec/lib/internal_metric/global_spec.rb b/spec/lib/internal_metric/global_spec.rb
index 2938f84..275cb15 100644
--- a/spec/lib/internal_metric/global_spec.rb
+++ b/spec/lib/internal_metric/global_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 module DiscoursePrometheus::InternalMetric
@@ -20,16 +22,16 @@ module DiscoursePrometheus::InternalMetric
         metric = Global.new
         metric.collect
 
-        expect(metric.sidekiq_paused).to eq({
-          {db: RailsMultisite::ConnectionManagement.current_db} => nil
-        })
+        expect(metric.sidekiq_paused).to eq(
+          { db: RailsMultisite::ConnectionManagement.current_db } => nil
+        )
 
         Sidekiq.pause!
         metric.collect
 
-        expect(metric.sidekiq_paused).to eq({
-          {db: RailsMultisite::ConnectionManagement.current_db} => 1
-        })
+        expect(metric.sidekiq_paused).to eq(
+          { db: RailsMultisite::ConnectionManagement.current_db } => 1
+        )
       end
     end
 
diff --git a/spec/lib/internal_metric/web_spec.rb b/spec/lib/internal_metric/web_spec.rb
index 8a087f0..4a261b0 100644
--- a/spec/lib/internal_metric/web_spec.rb
+++ b/spec/lib/internal_metric/web_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 module DiscoursePrometheus::InternalMetric
diff --git a/spec/lib/reporter/global_spec.rb b/spec/lib/reporter/global_spec.rb
index 146c6da..c81053c 100644
--- a/spec/lib/reporter/global_spec.rb
+++ b/spec/lib/reporter/global_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 module DiscoursePrometheus
diff --git a/spec/lib/reporter/process_spec.rb b/spec/lib/reporter/process_spec.rb
index 114bc67..c29686c 100644
--- a/spec/lib/reporter/process_spec.rb
+++ b/spec/lib/reporter/process_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 module DiscoursePrometheus
diff --git a/spec/middleware/metrics_spec.rb b/spec/middleware/metrics_spec.rb
index fcd6b64..ce622a6 100644
--- a/spec/middleware/metrics_spec.rb
+++ b/spec/middleware/metrics_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "rails_helper"
 
 describe ::DiscoursePrometheus::Middleware::Metrics do

GitHub sha: 4010dc0f