Enable frozen string in rest of app/models/**/*.rb

Partially addresses #47424.

app/models/programming_language.rb

+# frozen_string_literal: true
+
 class ProgrammingLanguage < ActiveRecord::Base
   validates :name, presence: true
   validates :color, allow_blank: false, color: true

app/models/project_services/asana_service.rb

+# frozen_string_literal: true
+
 require 'asana'
 
 class AsanaService < Service

app/models/project_services/assembla_service.rb

+# frozen_string_literal: true
+
 class AssemblaService < Service
   prop_accessor :token, :subdomain
   validates :token, presence: true, if: :activated?

app/models/project_services/bamboo_service.rb

+# frozen_string_literal: true
+
 class BambooService < CiService
   include ReactiveService
 

app/models/project_services/bugzilla_service.rb

+# frozen_string_literal: true
+
 class BugzillaService < IssueTrackerService
   validates :project_url, :issues_url, :new_issue_url, presence: true, public_url: true, if: :activated?
 

app/models/project_services/buildkite_service.rb

+# frozen_string_literal: true
+
 require "addressable/uri"
 
 class BuildkiteService < CiService

app/models/project_services/builds_email_service.rb

+# frozen_string_literal: true
+
 # This class is to be removed with 9.1
 # We should also by then remove BuildsEmailService from database
 class BuildsEmailService < Service

app/models/project_services/campfire_service.rb

+# frozen_string_literal: true
+
 class CampfireService < Service
   prop_accessor :token, :subdomain, :room
   validates :token, presence: true, if: :activated?
@@ -82,7 +84,7 @@ class CampfireService < Service
     before = push[:before]
     after = push[:after]
 
-    message = ""
+    message = []
     message << "[#{project.full_name}] "
     message << "#{push[:user_name]} "
 
@@ -95,6 +97,6 @@ class CampfireService < Service
       message << "#{project.web_url}/compare/#{before}...#{after}"
     end
 
-    message
+    message.join
   end
 end

app/models/project_services/chat_message/base_message.rb

+# frozen_string_literal: true
+
 require 'slack-notifier'
 
 module ChatMessage

app/models/project_services/chat_message/issue_message.rb

+# frozen_string_literal: true
+
 module ChatMessage
   class IssueMessage < BaseMessage
     attr_reader :title

app/models/project_services/chat_message/merge_message.rb

+# frozen_string_literal: true
+
 module ChatMessage
   class MergeMessage < BaseMessage
     attr_reader :merge_request_iid

app/models/project_services/chat_message/note_message.rb

+# frozen_string_literal: true
+
 module ChatMessage
   class NoteMessage < BaseMessage
     attr_reader :note

app/models/project_services/chat_message/pipeline_message.rb

+# frozen_string_literal: true
+
 module ChatMessage
   class PipelineMessage < BaseMessage
     attr_reader :ref_type

app/models/project_services/chat_message/push_message.rb

+# frozen_string_literal: true
+
 module ChatMessage
   class PushMessage < BaseMessage
     attr_reader :after

app/models/project_services/chat_message/wiki_page_message.rb

+# frozen_string_literal: true
+
 module ChatMessage
   class WikiPageMessage < BaseMessage
     attr_reader :title

app/models/project_services/chat_notification_service.rb

+# frozen_string_literal: true
+
 # Base class for Chat notifications services
 # This class is not meant to be used directly, but only to inherit from.
 class ChatNotificationService < Service

app/models/project_services/ci_service.rb

+# frozen_string_literal: true
+
 # Base class for CI services
 # List methods you need to implement to get your CI service
 # working with GitLab Merge Requests

app/models/project_services/custom_issue_tracker_service.rb

+# frozen_string_literal: true
+
 class CustomIssueTrackerService < IssueTrackerService
   validates :project_url, :issues_url, :new_issue_url, presence: true, public_url: true, if: :activated?
 

app/models/project_services/deployment_service.rb

+# frozen_string_literal: true
+
 # Base class for deployment services
 #
 # These services integrate with a deployment solution like Kubernetes/OpenShift,

app/models/project_services/drone_ci_service.rb

+# frozen_string_literal: true
+
 class DroneCiService < CiService
   include ReactiveService
 

app/models/project_services/emails_on_push_service.rb

+# frozen_string_literal: true
+
 class EmailsOnPushService < Service
   boolean_accessor :send_from_committer_email
   boolean_accessor :disable_diffs

app/models/project_services/external_wiki_service.rb

+# frozen_string_literal: true
+
 class ExternalWikiService < Service
   prop_accessor :external_wiki_url
 

app/models/project_services/flowdock_service.rb

+# frozen_string_literal: true
+
 require "flowdock-git-hook"
 
 # Flow dock depends on Grit to compute the number of commits between two given

app/models/project_services/gemnasium_service.rb

+# frozen_string_literal: true
+
 require "gemnasium/gitlab_service"
 
 class GemnasiumService < Service

app/models/project_services/gitlab_issue_tracker_service.rb

+# frozen_string_literal: true
+
 class GitlabIssueTrackerService < IssueTrackerService
   include Gitlab::Routing
 

app/models/project_services/hangouts_chat_service.rb

+# frozen_string_literal: true
+
 require 'hangouts_chat'
 
 class HangoutsChatService < ChatNotificationService

app/models/project_services/hipchat_service.rb

+# frozen_string_literal: true
+
 class HipchatService < Service
   include ActionView::Helpers::SanitizeHelper
 
@@ -108,7 +110,7 @@ class HipchatService < Service
     before = push[:before]
     after = push[:after]
 
-    message = ""
+    message = []
     message << "#{push[:user_name]} "
 
     if Gitlab::Git.blank_ref?(before)
@@ -132,7 +134,7 @@ class HipchatService < Service
       end
     end
 
-    message
+    message.join
   end
 
   def markdown(text, options = {})
@@ -165,11 +167,11 @@ class HipchatService < Service
     description = obj_attr[:description]
 
     issue_link = "<a href=\"#{issue_url}\">issue ##{issue_iid}</a>"
-    message = "#{user_name} #{state} #{issue_link} in #{project_link}: <b>#{title}</b>"
 
+    message = ["#{user_name} #{state} #{issue_link} in #{project_link}: <b>#{title}</b>"]
     message << "<pre>#{markdown(description)}</pre>"
 
-    message
+    message.join
   end
 
   def create_merge_request_message(data)
@@ -184,12 +186,11 @@ class HipchatService < Service
 
     merge_request_url = "#{project_url}/merge_requests/#{merge_request_id}"
     merge_request_link = "<a href=\"#{merge_request_url}\">merge request !#{merge_request_id}</a>"
-    message = "#{user_name} #{state} #{merge_request_link} in " \
-      "#{project_link}: <b>#{title}</b>"
+    message = ["#{user_name} #{state} #{merge_request_link} in " \
+      "#{project_link}: <b>#{title}</b>"]
 
     message << "<pre>#{markdown(description)}</pre>"
-
-    message
+    message.join
   end
 
   def format_title(title)
@@ -235,12 +236,11 @@ class HipchatService < Service
     end
 
     subject_html = "<a href=\"#{note_url}\">#{subject_type} #{subject_desc}</a>"
-    message = "#{user_name} commented on #{subject_html} in #{project_link}: "
+    message = ["#{user_name} commented on #{subject_html} in #{project_link}: "]
     message << title
 
     message << "<pre>#{markdown(note, ref: commit_id)}</pre>"
-
-    message
+    message.join
   end
 
   def create_pipeline_message(data)

app/models/project_services/irker_service.rb

+# frozen_string_literal: true
+
 require 'uri'
 
 class IrkerService < Service

app/models/project_services/issue_tracker_service.rb

+# frozen_string_literal: true
+
 class IssueTrackerService < Service
   validate :one_issue_tracker, if: :activated?, on: :manual_change
 

app/models/project_services/jira_service.rb

+# frozen_string_literal: true
+
 class JiraService < IssueTrackerService
   include Gitlab::Routing
   include ApplicationHelper

app/models/project_services/kubernetes_service.rb

+# frozen_string_literal: true
+
 ##
 # NOTE:
 # We'll move this class to Clusters::Platforms::Kubernetes, which contains exactly the same logic.

app/models/project_services/mattermost_service.rb

+# frozen_string_literal: true
+
 class MattermostService < ChatNotificationService
   def title
     'Mattermost notifications'

app/models/project_services/mattermost_slash_commands_service.rb

+# frozen_string_literal: true
+
 class MattermostSlashCommandsService < SlashCommandsService
   include TriggersHelper
 

app/models/project_services/microsoft_teams_service.rb

+# frozen_string_literal: true
+
 class MicrosoftTeamsService < ChatNotificationService
   def title
     'Microsoft Teams Notification'

app/models/project_services/mock_ci_service.rb

+# frozen_string_literal: true
+
 # For an example companion mocking service, see https://gitlab.com/gitlab-org/gitlab-mock-ci-service
 class MockCiService < CiService
   ALLOWED_STATES = %w[failed canceled running pending success success_with_warnings skipped not_found].freeze

app/models/project_services/mock_deployment_service.rb

+# frozen_string_literal: true
+
 class MockDeploymentService < DeploymentService
   def title
     'Mock deployment'

app/models/project_services/mock_monitoring_service.rb

+# frozen_string_literal: true
+
 class MockMonitoringService < MonitoringService
   def title
     'Mock monitoring'

app/models/project_services/monitoring_service.rb

+# frozen_string_literal: true
+
 # Base class for monitoring services
 #
 # These services integrate with a deployment solution like Prometheus

app/models/project_services/packagist_service.rb

+# frozen_string_literal: true
+
 class PackagistService < Service
   prop_accessor :username, :token, :server
 

app/models/project_services/pipelines_email_service.rb

+# frozen_string_literal: true
+
 class PipelinesEmailService < Service
   prop_accessor :recipients
   boolean_accessor :notify_only_broken_pipelines

app/models/project_services/pivotaltracker_service.rb

+# frozen_string_literal: true
+
 class PivotaltrackerService < Service
   API_ENDPOINT = 'https://www.pivotaltracker.com/services/v5/source_commits'.freeze
 

app/models/project_services/prometheus_service.rb

+# frozen_string_literal: true
+
 class PrometheusService < MonitoringService
   include PrometheusAdapter
 

app/models/project_services/pushover_service.rb

+# frozen_string_literal: true
+
 class PushoverService < Service
   BASE_URI = 'https://api.pushover.net/1'.freeze
 
@@ -79,7 +81,7 @@ class PushoverService < Service
       end
 
     if data[:total_commits_count] > 0
-      message << "\nTotal commits count: #{data[:total_commits_count]}"
+      message = [message, "Total commits count: #{data[:total_commits_count]}"].join("\n")
     end
 
     pushover_data = {

app/models/project_services/redmine_service.rb

+# frozen_string_literal: true
+
 class RedmineService < IssueTrackerService
   validates :project_url, :issues_url, :new_issue_url, presence: true, public_url: true, if: :activated?
 

app/models/project_services/slack_service.rb

+# frozen_string_literal: true
+
 class SlackService < ChatNotificationService
   def title
     'Slack notifications'

app/models/project_services/slack_slash_commands_service.rb

+# frozen_string_literal: true
+
 class SlackSlashCommandsService < SlashCommandsService
   include TriggersHelper
 

app/models/project_services/slash_commands_service.rb

+# frozen_string_literal: true
+
 # Base class for Chat services
 # This class is not meant to be used directly, but only to inherrit from.
 class SlashCommandsService < Service

app/models/project_services/teamcity_service.rb

+# frozen_string_literal: true
+
 class TeamcityService < CiService
   include ReactiveService
 

app/models/protected_branch/merge_access_level.rb

+# frozen_string_literal: true
+
 class ProtectedBranch::MergeAccessLevel < ActiveRecord::Base
   include ProtectedBranchAccess
 end

app/models/protected_branch/push_access_level.rb

+# frozen_string_literal: true
+
 class ProtectedBranch::PushAccessLevel < ActiveRecord::Base
   include ProtectedBranchAccess
 end

app/models/protected_tag/create_access_level.rb

+# frozen_string_literal: true
+
 class ProtectedTag::CreateAccessLevel < ActiveRecord::Base
   include ProtectedTagAccess
 

app/models/repository_language.rb

+# frozen_string_literal: true
+
 class RepositoryLanguage < ActiveRecord::Base
   belongs_to :project
   belongs_to :programming_language

app/models/site_statistic.rb

+# frozen_string_literal: true
+
 class SiteStatistic < ActiveRecord::Base
   # prevents the creation of multiple rows
   default_value_for :id, 1

app/models/storage/hashed_project.rb

+# frozen_string_literal: true
+
 module Storage
   class HashedProject
     attr_accessor :project

app/models/storage/legacy_project.rb

+# frozen_string_literal: true
+
 module Storage
   class LegacyProject
     attr_accessor :project

changelogs/unreleased/frozen-string-enable-app-models-even-more-still.yml

+---
+title: Enable frozen string in rest of app/models/**/*.rb
+merge_request: gfyoung
+author:
+type: performance