Enable more frozen string in app/services/**/*.rbrepo-forks/gitlab-ce-frozen-string-enable-apps-services-inner-more

Partially addresses #47424.

99 files changed, 207 insertions, 3 deletions

diff --git a/app/services/lfs/file_transformer.rb b/app/services/lfs/file_transformer.rb
index 69281ee3137..c8eccb8e6cd 100644
--- a/app/services/lfs/file_transformer.rb
+++ b/app/services/lfs/file_transformer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Lfs
   # Usage: Calling `new_file` check to see if a file should be in LFS and
   #        return a transformed result with `content` and `encoding` to commit.
diff --git a/app/services/lfs/lock_file_service.rb b/app/services/lfs/lock_file_service.rb
index bbe10f84ef4..78434909d68 100644
--- a/app/services/lfs/lock_file_service.rb
+++ b/app/services/lfs/lock_file_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Lfs
   class LockFileService < BaseService
     def execute
diff --git a/app/services/lfs/locks_finder_service.rb b/app/services/lfs/locks_finder_service.rb
index 13c6cc6f81c..d52cf0e3cc4 100644
--- a/app/services/lfs/locks_finder_service.rb
+++ b/app/services/lfs/locks_finder_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Lfs
   class LocksFinderService < BaseService
     def execute
diff --git a/app/services/lfs/unlock_file_service.rb b/app/services/lfs/unlock_file_service.rb
index 7e3edf21d54..4d1443bf772 100644
--- a/app/services/lfs/unlock_file_service.rb
+++ b/app/services/lfs/unlock_file_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Lfs
   class UnlockFileService < BaseService
     def execute
diff --git a/app/services/mattermost/create_team_service.rb b/app/services/mattermost/create_team_service.rb
index e3206810f3a..afcd6439a14 100644
--- a/app/services/mattermost/create_team_service.rb
+++ b/app/services/mattermost/create_team_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Mattermost
   class CreateTeamService < ::BaseService
     def initialize(group, current_user)
diff --git a/app/services/members/approve_access_request_service.rb b/app/services/members/approve_access_request_service.rb
index 6be08b590bc..52b890d1821 100644
--- a/app/services/members/approve_access_request_service.rb
+++ b/app/services/members/approve_access_request_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Members
   class ApproveAccessRequestService < Members::BaseService
     def execute(access_requester, skip_authorization: false, skip_log_audit_event: false)
diff --git a/app/services/members/base_service.rb b/app/services/members/base_service.rb
index 74556fb20cf..8248f1441d7 100644
--- a/app/services/members/base_service.rb
+++ b/app/services/members/base_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Members
   class BaseService < ::BaseService
     # current_user - The user that performs the action
diff --git a/app/services/members/create_service.rb b/app/services/members/create_service.rb
index bc6a9405aac..714b8586737 100644
--- a/app/services/members/create_service.rb
+++ b/app/services/members/create_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Members
   class CreateService < Members::BaseService
     DEFAULT_LIMIT = 100
diff --git a/app/services/members/destroy_service.rb b/app/services/members/destroy_service.rb
index 5b51e1982f1..aca0ba66646 100644
--- a/app/services/members/destroy_service.rb
+++ b/app/services/members/destroy_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Members
   class DestroyService < Members::BaseService
     def execute(member, skip_authorization: false)
diff --git a/app/services/members/request_access_service.rb b/app/services/members/request_access_service.rb
index 24293b30005..b9b0550e290 100644
--- a/app/services/members/request_access_service.rb
+++ b/app/services/members/request_access_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Members
   class RequestAccessService < Members::BaseService
     def execute(source)
diff --git a/app/services/members/update_service.rb b/app/services/members/update_service.rb
index cb19cf01dd7..1f5618dae53 100644
--- a/app/services/members/update_service.rb
+++ b/app/services/members/update_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Members
   class UpdateService < Members::BaseService
     # returns the updated member
diff --git a/app/services/merge_requests/add_todo_when_build_fails_service.rb b/app/services/merge_requests/add_todo_when_build_fails_service.rb
index 6805b2f7d1c..79c43b8e7d5 100644
--- a/app/services/merge_requests/add_todo_when_build_fails_service.rb
+++ b/app/services/merge_requests/add_todo_when_build_fails_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class AddTodoWhenBuildFailsService < MergeRequests::BaseService
     # Adds a todo to the parent merge_request when a CI build fails
diff --git a/app/services/merge_requests/assign_issues_service.rb b/app/services/merge_requests/assign_issues_service.rb
index 8c6c4841020..e9107b9998e 100644
--- a/app/services/merge_requests/assign_issues_service.rb
+++ b/app/services/merge_requests/assign_issues_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class AssignIssuesService < BaseService
     def assignable_issues
diff --git a/app/services/merge_requests/base_service.rb b/app/services/merge_requests/base_service.rb
index 4c420b38258..e6dd0e12a3a 100644
--- a/app/services/merge_requests/base_service.rb
+++ b/app/services/merge_requests/base_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class BaseService < ::IssuableBaseService
     def create_note(merge_request, state = merge_request.state)
diff --git a/app/services/merge_requests/build_service.rb b/app/services/merge_requests/build_service.rb
index a98bbdf74dd..bc988eb2a26 100644
--- a/app/services/merge_requests/build_service.rb
+++ b/app/services/merge_requests/build_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class BuildService < MergeRequests::BaseService
     include Gitlab::Utils::StrongMemoize
@@ -140,7 +142,8 @@ module MergeRequests
       closes_issue = "Closes #{issue.to_reference}"
 
       if description.present?
-        merge_request.description += closes_issue.prepend("\n\n")
+        descr_parts = [merge_request.description, closes_issue]
+        merge_request.description = descr_parts.join("\n\n")
       else
         merge_request.description = closes_issue
       end
@@ -164,9 +167,11 @@ module MergeRequests
       return if merge_request.title.present?
 
       if issue_iid.present?
-        merge_request.title = "Resolve #{issue.to_reference}"
+        title_parts = ["Resolve #{issue.to_reference}"]
         branch_title = source_branch.downcase.remove(issue_iid.downcase).titleize.humanize
-        merge_request.title += " \"#{branch_title}\"" if branch_title.present?
+
+        title_parts << "\"#{branch_title}\"" if branch_title.present?
+        merge_request.title = title_parts.join(' ')
       end
     end
 
diff --git a/app/services/merge_requests/close_service.rb b/app/services/merge_requests/close_service.rb
index db701c1145d..04527bb9713 100644
--- a/app/services/merge_requests/close_service.rb
+++ b/app/services/merge_requests/close_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class CloseService < MergeRequests::BaseService
     def execute(merge_request, commit = nil)
diff --git a/app/services/merge_requests/conflicts/base_service.rb b/app/services/merge_requests/conflicts/base_service.rb
index b50875347d9..402f6c4e4c0 100644
--- a/app/services/merge_requests/conflicts/base_service.rb
+++ b/app/services/merge_requests/conflicts/base_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   module Conflicts
     class BaseService
diff --git a/app/services/merge_requests/conflicts/list_service.rb b/app/services/merge_requests/conflicts/list_service.rb
index 72cbc49adb2..c6b3a6a1a69 100644
--- a/app/services/merge_requests/conflicts/list_service.rb
+++ b/app/services/merge_requests/conflicts/list_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   module Conflicts
     class ListService < MergeRequests::Conflicts::BaseService
diff --git a/app/services/merge_requests/conflicts/resolve_service.rb b/app/services/merge_requests/conflicts/resolve_service.rb
index 27cafd2d7d9..b9f734310be 100644
--- a/app/services/merge_requests/conflicts/resolve_service.rb
+++ b/app/services/merge_requests/conflicts/resolve_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   module Conflicts
     class ResolveService < MergeRequests::Conflicts::BaseService
diff --git a/app/services/merge_requests/create_from_issue_service.rb b/app/services/merge_requests/create_from_issue_service.rb
index 3407b312700..fd91dc4acd0 100644
--- a/app/services/merge_requests/create_from_issue_service.rb
+++ b/app/services/merge_requests/create_from_issue_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class CreateFromIssueService < MergeRequests::CreateService
     def initialize(project, user, params)
diff --git a/app/services/merge_requests/create_service.rb b/app/services/merge_requests/create_service.rb
index fe1ac70781e..c36a2ecbfe3 100644
--- a/app/services/merge_requests/create_service.rb
+++ b/app/services/merge_requests/create_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class CreateService < MergeRequests::BaseService
     def execute
diff --git a/app/services/merge_requests/delete_non_latest_diffs_service.rb b/app/services/merge_requests/delete_non_latest_diffs_service.rb
index 40079b21189..2a8ea316921 100644
--- a/app/services/merge_requests/delete_non_latest_diffs_service.rb
+++ b/app/services/merge_requests/delete_non_latest_diffs_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class DeleteNonLatestDiffsService
     BATCH_SIZE = 10
diff --git a/app/services/merge_requests/ff_merge_service.rb b/app/services/merge_requests/ff_merge_service.rb
index bffc09c34f0..479e0fe6699 100644
--- a/app/services/merge_requests/ff_merge_service.rb
+++ b/app/services/merge_requests/ff_merge_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   # MergeService class
   #
diff --git a/app/services/merge_requests/get_urls_service.rb b/app/services/merge_requests/get_urls_service.rb
index 668a1741736..7c88c9abb41 100644
--- a/app/services/merge_requests/get_urls_service.rb
+++ b/app/services/merge_requests/get_urls_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class GetUrlsService < BaseService
     attr_reader :project
diff --git a/app/services/merge_requests/merge_service.rb b/app/services/merge_requests/merge_service.rb
index 3d587f97906..fb44f809c41 100644
--- a/app/services/merge_requests/merge_service.rb
+++ b/app/services/merge_requests/merge_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   # MergeService class
   #
diff --git a/app/services/merge_requests/merge_when_pipeline_succeeds_service.rb b/app/services/merge_requests/merge_when_pipeline_succeeds_service.rb
index 9a4e6eb2e88..973e5b64e88 100644
--- a/app/services/merge_requests/merge_when_pipeline_succeeds_service.rb
+++ b/app/services/merge_requests/merge_when_pipeline_succeeds_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class MergeWhenPipelineSucceedsService < MergeRequests::BaseService
     # Marks the passed `merge_request` to be merged when the pipeline succeeds or
diff --git a/app/services/merge_requests/post_merge_service.rb b/app/services/merge_requests/post_merge_service.rb
index 7606d68ff29..3d2aea4e9b6 100644
--- a/app/services/merge_requests/post_merge_service.rb
+++ b/app/services/merge_requests/post_merge_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   # PostMergeService class
   #
diff --git a/app/services/merge_requests/rebase_service.rb b/app/services/merge_requests/rebase_service.rb
index c741e913860..31b3ebf311e 100644
--- a/app/services/merge_requests/rebase_service.rb
+++ b/app/services/merge_requests/rebase_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class RebaseService < MergeRequests::WorkingCopyBaseService
     REBASE_ERROR = 'Rebase failed. Please rebase locally'.freeze
diff --git a/app/services/merge_requests/refresh_service.rb b/app/services/merge_requests/refresh_service.rb
index 0127d781686..48da796505f 100644
--- a/app/services/merge_requests/refresh_service.rb
+++ b/app/services/merge_requests/refresh_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class RefreshService < MergeRequests::BaseService
     def execute(oldrev, newrev, ref)
diff --git a/app/services/merge_requests/reload_diffs_service.rb b/app/services/merge_requests/reload_diffs_service.rb
index 2ec7b403903..8d85dc9eb5f 100644
--- a/app/services/merge_requests/reload_diffs_service.rb
+++ b/app/services/merge_requests/reload_diffs_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class ReloadDiffsService
     def initialize(merge_request, current_user)
diff --git a/app/services/merge_requests/reopen_service.rb b/app/services/merge_requests/reopen_service.rb
index 8f1c95ac1b7..f2fc13ad028 100644
--- a/app/services/merge_requests/reopen_service.rb
+++ b/app/services/merge_requests/reopen_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class ReopenService < MergeRequests::BaseService
     def execute(merge_request)
diff --git a/app/services/merge_requests/resolved_discussion_notification_service.rb b/app/services/merge_requests/resolved_discussion_notification_service.rb
index 66a0cbc81d4..03ded1512f9 100644
--- a/app/services/merge_requests/resolved_discussion_notification_service.rb
+++ b/app/services/merge_requests/resolved_discussion_notification_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class ResolvedDiscussionNotificationService < MergeRequests::BaseService
     def execute(merge_request)
diff --git a/app/services/merge_requests/squash_service.rb b/app/services/merge_requests/squash_service.rb
index a40fb2786bd..a439a380255 100644
--- a/app/services/merge_requests/squash_service.rb
+++ b/app/services/merge_requests/squash_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class SquashService < MergeRequests::WorkingCopyBaseService
     def execute(merge_request)
diff --git a/app/services/merge_requests/update_service.rb b/app/services/merge_requests/update_service.rb
index 7350725e223..b112edbce7f 100644
--- a/app/services/merge_requests/update_service.rb
+++ b/app/services/merge_requests/update_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class UpdateService < MergeRequests::BaseService
     def execute(merge_request)
diff --git a/app/services/merge_requests/working_copy_base_service.rb b/app/services/merge_requests/working_copy_base_service.rb
index 186e05bf966..2d2be1f4c25 100644
--- a/app/services/merge_requests/working_copy_base_service.rb
+++ b/app/services/merge_requests/working_copy_base_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MergeRequests
   class WorkingCopyBaseService < MergeRequests::BaseService
     attr_reader :merge_request
diff --git a/app/services/milestones/base_service.rb b/app/services/milestones/base_service.rb
index cce0863d611..f30194c0bfe 100644
--- a/app/services/milestones/base_service.rb
+++ b/app/services/milestones/base_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Milestones
   class BaseService < ::BaseService
     # Parent can either a group or a project
diff --git a/app/services/milestones/close_service.rb b/app/services/milestones/close_service.rb
index 5b06c4b601d..a252f5c144e 100644
--- a/app/services/milestones/close_service.rb
+++ b/app/services/milestones/close_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Milestones
   class CloseService < Milestones::BaseService
     def execute(milestone)
diff --git a/app/services/milestones/create_service.rb b/app/services/milestones/create_service.rb
index ed2e833d833..6c3edd2e147 100644
--- a/app/services/milestones/create_service.rb
+++ b/app/services/milestones/create_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Milestones
   class CreateService < Milestones::BaseService
     def execute
diff --git a/app/services/milestones/destroy_service.rb b/app/services/milestones/destroy_service.rb
index b18651476a8..15c04525075 100644
--- a/app/services/milestones/destroy_service.rb
+++ b/app/services/milestones/destroy_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Milestones
   class DestroyService < Milestones::BaseService
     def execute(milestone)
diff --git a/app/services/milestones/promote_service.rb b/app/services/milestones/promote_service.rb
index 2187f26d1ed..37aa6d3a9bc 100644
--- a/app/services/milestones/promote_service.rb
+++ b/app/services/milestones/promote_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Milestones
   class PromoteService < Milestones::BaseService
     PromoteMilestoneError = Class.new(StandardError)
diff --git a/app/services/milestones/reopen_service.rb b/app/services/milestones/reopen_service.rb
index 3efb33157c5..125a3ec1367 100644
--- a/app/services/milestones/reopen_service.rb
+++ b/app/services/milestones/reopen_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Milestones
   class ReopenService < Milestones::BaseService
     def execute(milestone)
diff --git a/app/services/milestones/update_service.rb b/app/services/milestones/update_service.rb
index 74edbf9b41d..81b20943bab 100644
--- a/app/services/milestones/update_service.rb
+++ b/app/services/milestones/update_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Milestones
   class UpdateService < Milestones::BaseService
     def execute(milestone)
diff --git a/app/services/notes/build_service.rb b/app/services/notes/build_service.rb
index 77e7b8a5ea7..df5fe65de3c 100644
--- a/app/services/notes/build_service.rb
+++ b/app/services/notes/build_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Notes
   class BuildService < ::BaseService
     def execute
diff --git a/app/services/notes/create_service.rb b/app/services/notes/create_service.rb
index 9ea28733f5f..049e6c5a871 100644
--- a/app/services/notes/create_service.rb
+++ b/app/services/notes/create_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Notes
   class CreateService < ::BaseService
     def execute
diff --git a/app/services/notes/destroy_service.rb b/app/services/notes/destroy_service.rb
index fb78420d324..64e9accd97f 100644
--- a/app/services/notes/destroy_service.rb
+++ b/app/services/notes/destroy_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Notes
   class DestroyService < BaseService
     def execute(note)
diff --git a/app/services/notes/post_process_service.rb b/app/services/notes/post_process_service.rb
index 199b8028dbc..48722cc2a79 100644
--- a/app/services/notes/post_process_service.rb
+++ b/app/services/notes/post_process_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Notes
   class PostProcessService
     attr_accessor :note
diff --git a/app/services/notes/quick_actions_service.rb b/app/services/notes/quick_actions_service.rb
index 0a33d5f3f3d..7280449bb1c 100644
--- a/app/services/notes/quick_actions_service.rb
+++ b/app/services/notes/quick_actions_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Notes
   class QuickActionsService < BaseService
     UPDATE_SERVICES = {
diff --git a/app/services/notes/render_service.rb b/app/services/notes/render_service.rb
index efc9d6da2aa..0e1a55ae2ff 100644
--- a/app/services/notes/render_service.rb
+++ b/app/services/notes/render_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Notes
   class RenderService < BaseRenderer
     # Renders a collection of Note instances.
diff --git a/app/services/notes/resolve_service.rb b/app/services/notes/resolve_service.rb
index 0db8ee809a9..cf24795f050 100644
--- a/app/services/notes/resolve_service.rb
+++ b/app/services/notes/resolve_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Notes
   class ResolveService < ::BaseService
     def execute(note)
diff --git a/app/services/notes/update_service.rb b/app/services/notes/update_service.rb
index e16ef398184..35db409eb27 100644
--- a/app/services/notes/update_service.rb
+++ b/app/services/notes/update_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Notes
   class UpdateService < BaseService
     def execute(note)
diff --git a/app/services/projects/after_import_service.rb b/app/services/projects/after_import_service.rb
index 3047268b2d1..bbdde4408d2 100644
--- a/app/services/projects/after_import_service.rb
+++ b/app/services/projects/after_import_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class AfterImportService
     RESERVED_REF_PREFIXES = Repository::RESERVED_REFS_NAMES.map { |n| File.join('refs', n, '/') }
diff --git a/app/services/projects/autocomplete_service.rb b/app/services/projects/autocomplete_service.rb
index 9d0eaaf3152..10eb2cea4a2 100644
--- a/app/services/projects/autocomplete_service.rb
+++ b/app/services/projects/autocomplete_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class AutocompleteService < BaseService
     def issues
diff --git a/app/services/projects/base_move_relations_service.rb b/app/services/projects/base_move_relations_service.rb
index e8fd3ef57e5..78cc2869b72 100644
--- a/app/services/projects/base_move_relations_service.rb
+++ b/app/services/projects/base_move_relations_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class BaseMoveRelationsService < BaseService
     attr_reader :source_project
diff --git a/app/services/projects/batch_count_service.rb b/app/services/projects/batch_count_service.rb
index 178ebc5a143..aec3b32da89 100644
--- a/app/services/projects/batch_count_service.rb
+++ b/app/services/projects/batch_count_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Service class for getting and caching the number of elements of several projects
 # Warning: do not user this service with a really large set of projects
 # because the service use maps to retrieve the project ids.
diff --git a/app/services/projects/batch_forks_count_service.rb b/app/services/projects/batch_forks_count_service.rb
index e61fe6c86b2..9bf369df999 100644
--- a/app/services/projects/batch_forks_count_service.rb
+++ b/app/services/projects/batch_forks_count_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Service class for getting and caching the number of forks of several projects
 # Warning: do not user this service with a really large set of projects
 # because the service use maps to retrieve the project ids
diff --git a/app/services/projects/batch_open_issues_count_service.rb b/app/services/projects/batch_open_issues_count_service.rb
index 3b0ade2419b..d375fcf9dbd 100644
--- a/app/services/projects/batch_open_issues_count_service.rb
+++ b/app/services/projects/batch_open_issues_count_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Service class for getting and caching the number of issues of several projects
 # Warning: do not user this service with a really large set of projects
 # because the service use maps to retrieve the project ids
diff --git a/app/services/projects/count_service.rb b/app/services/projects/count_service.rb
index 4c8e000928f..3cee80c7bbc 100644
--- a/app/services/projects/count_service.rb
+++ b/app/services/projects/count_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   # Base class for the various service classes that count project data (e.g.
   # issues or forks).
diff --git a/app/services/projects/create_from_template_service.rb b/app/services/projects/create_from_template_service.rb
index 29b133cc466..f5c48e56880 100644
--- a/app/services/projects/create_from_template_service.rb
+++ b/app/services/projects/create_from_template_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class CreateFromTemplateService < BaseService
     def initialize(user, params)
diff --git a/app/services/projects/create_service.rb b/app/services/projects/create_service.rb
index 85491089d8e..02a3a3eb096 100644
--- a/app/services/projects/create_service.rb
+++ b/app/services/projects/create_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class CreateService < BaseService
     def initialize(user, params)
diff --git a/app/services/projects/destroy_service.rb b/app/services/projects/destroy_service.rb
index 87173cc79ec..46a8a5e4d98 100644
--- a/app/services/projects/destroy_service.rb
+++ b/app/services/projects/destroy_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class DestroyService < BaseService
     include Gitlab::ShellAdapter
diff --git a/app/services/projects/download_service.rb b/app/services/projects/download_service.rb
index 604747e39d0..dd297c9ba43 100644
--- a/app/services/projects/download_service.rb
+++ b/app/services/projects/download_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class DownloadService < BaseService
     WHITELIST = [
diff --git a/app/services/projects/enable_deploy_key_service.rb b/app/services/projects/enable_deploy_key_service.rb
index 121385afca3..b7c172028e9 100644
--- a/app/services/projects/enable_deploy_key_service.rb
+++ b/app/services/projects/enable_deploy_key_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class EnableDeployKeyService < BaseService
     def execute
diff --git a/app/services/projects/fork_service.rb b/app/services/projects/fork_service.rb
index a8aafa9fb4f..33ad2120a75 100644
--- a/app/services/projects/fork_service.rb
+++ b/app/services/projects/fork_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class ForkService < BaseService
     def execute(fork_to_project = nil)
diff --git a/app/services/projects/forks_count_service.rb b/app/services/projects/forks_count_service.rb
index dc6eb19affd..b570c6d4754 100644
--- a/app/services/projects/forks_count_service.rb
+++ b/app/services/projects/forks_count_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   # Service class for getting and caching the number of forks of a project.
   class ForksCountService < Projects::CountService
diff --git a/app/services/projects/gitlab_projects_import_service.rb b/app/services/projects/gitlab_projects_import_service.rb
index a16268f4fd2..bc6e9caebb8 100644
--- a/app/services/projects/gitlab_projects_import_service.rb
+++ b/app/services/projects/gitlab_projects_import_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This service is an adapter used to for the GitLab Import feature, and
 # creating a project from a template.
 # The latter will under the hood just import an archive supplied by GitLab.
diff --git a/app/services/projects/group_links/create_service.rb b/app/services/projects/group_links/create_service.rb
index 35624577024..1392775f805 100644
--- a/app/services/projects/group_links/create_service.rb
+++ b/app/services/projects/group_links/create_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   module GroupLinks
     class CreateService < BaseService
diff --git a/app/services/projects/group_links/destroy_service.rb b/app/services/projects/group_links/destroy_service.rb
index e3a20b4c1e4..8aefad048ce 100644
--- a/app/services/projects/group_links/destroy_service.rb
+++ b/app/services/projects/group_links/destroy_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   module GroupLinks
     class DestroyService < BaseService
diff --git a/app/services/projects/hashed_storage/migrate_attachments_service.rb b/app/services/projects/hashed_storage/migrate_attachments_service.rb
index bc897d891d5..649c916a593 100644
--- a/app/services/projects/hashed_storage/migrate_attachments_service.rb
+++ b/app/services/projects/hashed_storage/migrate_attachments_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   module HashedStorage
     AttachmentMigrationError = Class.new(StandardError)
diff --git a/app/services/projects/hashed_storage/migrate_repository_service.rb b/app/services/projects/hashed_storage/migrate_repository_service.rb
index 68c1af2396b..70f00b7fdeb 100644
--- a/app/services/projects/hashed_storage/migrate_repository_service.rb
+++ b/app/services/projects/hashed_storage/migrate_repository_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   module HashedStorage
     class MigrateRepositoryService < BaseService
diff --git a/app/services/projects/hashed_storage_migration_service.rb b/app/services/projects/hashed_storage_migration_service.rb
index 662702c1db5..1828c99a65e 100644
--- a/app/services/projects/hashed_storage_migration_service.rb
+++ b/app/services/projects/hashed_storage_migration_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class HashedStorageMigrationService < BaseService
     attr_reader :logger
diff --git a/app/services/projects/housekeeping_service.rb b/app/services/projects/housekeeping_service.rb
index 120d57a188d..2f6dc4207dd 100644
--- a/app/services/projects/housekeeping_service.rb
+++ b/app/services/projects/housekeeping_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Projects::HousekeepingService class
 #
 # Used for git housekeeping
diff --git a/app/services/projects/import_export/export_service.rb b/app/services/projects/import_export/export_service.rb
index 7bf0b90b491..e3491282a8a 100644
--- a/app/services/projects/import_export/export_service.rb
+++ b/app/services/projects/import_export/export_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   module ImportExport
     class ExportService < BaseService
diff --git a/app/services/projects/import_service.rb b/app/services/projects/import_service.rb
index 1781a01cbd4..60f400edfce 100644
--- a/app/services/projects/import_service.rb
+++ b/app/services/projects/import_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class ImportService < BaseService
     include Gitlab::ShellAdapter
diff --git a/app/services/projects/lfs_pointers/lfs_download_link_list_service.rb b/app/services/projects/lfs_pointers/lfs_download_link_list_service.rb
index d9fb74b090e..a837ea82e38 100644
--- a/app/services/projects/lfs_pointers/lfs_download_link_list_service.rb
+++ b/app/services/projects/lfs_pointers/lfs_download_link_list_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This service lists the download link from a remote source based on the
 # oids provided
 module Projects
diff --git a/app/services/projects/lfs_pointers/lfs_download_service.rb b/app/services/projects/lfs_pointers/lfs_download_service.rb
index 618c30b971f..7d4fa4e08df 100644
--- a/app/services/projects/lfs_pointers/lfs_download_service.rb
+++ b/app/services/projects/lfs_pointers/lfs_download_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This service downloads and links lfs objects from a remote URL
 module Projects
   module LfsPointers
diff --git a/app/services/projects/lfs_pointers/lfs_import_service.rb b/app/services/projects/lfs_pointers/lfs_import_service.rb
index b6b0dec142f..97ce681a911 100644
--- a/app/services/projects/lfs_pointers/lfs_import_service.rb
+++ b/app/services/projects/lfs_pointers/lfs_import_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This service manages the whole worflow of discovering the Lfs files in a
 # repository, linking them to the project and downloading (and linking) the non
 # existent ones.
diff --git a/app/services/projects/lfs_pointers/lfs_link_service.rb b/app/services/projects/lfs_pointers/lfs_link_service.rb
index d20bdf86c58..a2eba8e124e 100644
--- a/app/services/projects/lfs_pointers/lfs_link_service.rb
+++ b/app/services/projects/lfs_pointers/lfs_link_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Given a list of oids, this services links the existent Lfs Objects to the project
 module Projects
   module LfsPointers
diff --git a/app/services/projects/lfs_pointers/lfs_list_service.rb b/app/services/projects/lfs_pointers/lfs_list_service.rb
index b770982cbc0..22160017f4f 100644
--- a/app/services/projects/lfs_pointers/lfs_list_service.rb
+++ b/app/services/projects/lfs_pointers/lfs_list_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This service list all existent Lfs objects in a repository
 module Projects
   module LfsPointers
diff --git a/app/services/projects/move_access_service.rb b/app/services/projects/move_access_service.rb
index 3af3a22d486..8e2c3ad2f69 100644
--- a/app/services/projects/move_access_service.rb
+++ b/app/services/projects/move_access_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class MoveAccessService < BaseMoveRelationsService
     def execute(source_project, remove_remaining_elements: true)
diff --git a/app/services/projects/move_deploy_keys_projects_service.rb b/app/services/projects/move_deploy_keys_projects_service.rb
index dde420655b0..40a22837eaf 100644
--- a/app/services/projects/move_deploy_keys_projects_service.rb
+++ b/app/services/projects/move_deploy_keys_projects_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class MoveDeployKeysProjectsService < BaseMoveRelationsService
     def execute(source_project, remove_remaining_elements: true)
diff --git a/app/services/projects/move_forks_service.rb b/app/services/projects/move_forks_service.rb
index d2901ea1457..076a7a50aa9 100644
--- a/app/services/projects/move_forks_service.rb
+++ b/app/services/projects/move_forks_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class MoveForksService < BaseMoveRelationsService
     def execute(source_project, remove_remaining_elements: true)
diff --git a/app/services/projects/move_lfs_objects_projects_service.rb b/app/services/projects/move_lfs_objects_projects_service.rb
index 298da5f1a82..a5099519594 100644
--- a/app/services/projects/move_lfs_objects_projects_service.rb
+++ b/app/services/projects/move_lfs_objects_projects_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class MoveLfsObjectsProjectsService < BaseMoveRelationsService
     def execute(source_project, remove_remaining_elements: true)
diff --git a/app/services/projects/move_notification_settings_service.rb b/app/services/projects/move_notification_settings_service.rb
index f7be461a5da..746605d56f1 100644
--- a/app/services/projects/move_notification_settings_service.rb
+++ b/app/services/projects/move_notification_settings_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class MoveNotificationSettingsService < BaseMoveRelationsService
     def execute(source_project, remove_remaining_elements: true)
diff --git a/app/services/projects/move_project_authorizations_service.rb b/app/services/projects/move_project_authorizations_service.rb
index 5ef12fc49e5..60f2af88e99 100644
--- a/app/services/projects/move_project_authorizations_service.rb
+++ b/app/services/projects/move_project_authorizations_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # NOTE: This service cannot be used directly because it is part of a
 # a bigger process. Instead, use the service MoveAccessService which moves
 # project memberships, project group links, authorizations and refreshes
diff --git a/app/services/projects/move_project_group_links_service.rb b/app/services/projects/move_project_group_links_service.rb
index dbeffd7dae9..d9038030f7e 100644
--- a/app/services/projects/move_project_group_links_service.rb
+++ b/app/services/projects/move_project_group_links_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # NOTE: This service cannot be used directly because it is part of a
 # a bigger process. Instead, use the service MoveAccessService which moves
 # project memberships, project group links, authorizations and refreshes
diff --git a/app/services/projects/move_project_members_service.rb b/app/services/projects/move_project_members_service.rb
index 22a5f0a3fe6..bb0c0d10242 100644
--- a/app/services/projects/move_project_members_service.rb
+++ b/app/services/projects/move_project_members_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # NOTE: This service cannot be used directly because it is part of a
 # a bigger process. Instead, use the service MoveAccessService which moves
 # project memberships, project group links, authorizations and refreshes
diff --git a/app/services/projects/move_users_star_projects_service.rb b/app/services/projects/move_users_star_projects_service.rb
index 079fd5b9685..20121d429e2 100644
--- a/app/services/projects/move_users_star_projects_service.rb
+++ b/app/services/projects/move_users_star_projects_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class MoveUsersStarProjectsService < BaseMoveRelationsService
     def execute(source_project, remove_remaining_elements: true)
diff --git a/app/services/projects/open_issues_count_service.rb b/app/services/projects/open_issues_count_service.rb
index 78b1477186a..5d6620c3c54 100644
--- a/app/services/projects/open_issues_count_service.rb
+++ b/app/services/projects/open_issues_count_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   # Service class for counting and caching the number of open issues of a
   # project.
diff --git a/app/services/projects/open_merge_requests_count_service.rb b/app/services/projects/open_merge_requests_count_service.rb
index 77e6448fd5e..76ec13952ab 100644
--- a/app/services/projects/open_merge_requests_count_service.rb
+++ b/app/services/projects/open_merge_requests_count_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   # Service class for counting and caching the number of open merge requests of
   # a project.
diff --git a/app/services/projects/overwrite_project_service.rb b/app/services/projects/overwrite_project_service.rb
index ce94f147aa9..696e1b665b2 100644
--- a/app/services/projects/overwrite_project_service.rb
+++ b/app/services/projects/overwrite_project_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class OverwriteProjectService < BaseService
     def execute(source_project)
diff --git a/app/services/projects/participants_service.rb b/app/services/projects/participants_service.rb
index 21741913385..7080f388e53 100644
--- a/app/services/projects/participants_service.rb
+++ b/app/services/projects/participants_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class ParticipantsService < BaseService
     include Users::ParticipableService
diff --git a/app/services/projects/propagate_service_template.rb b/app/services/projects/propagate_service_template.rb
index a8ef2108492..fdfa91801ab 100644
--- a/app/services/projects/propagate_service_template.rb
+++ b/app/services/projects/propagate_service_template.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class PropagateServiceTemplate
     BATCH_SIZE = 100
diff --git a/app/services/projects/transfer_service.rb b/app/services/projects/transfer_service.rb
index 61acdd58021..a4a66330546 100644
--- a/app/services/projects/transfer_service.rb
+++ b/app/services/projects/transfer_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Projects::TransferService class
 #
 # Used for transfer project to another namespace
diff --git a/app/services/projects/unlink_fork_service.rb b/app/services/projects/unlink_fork_service.rb
index 842fe4e09c4..2c0d91fe34f 100644
--- a/app/services/projects/unlink_fork_service.rb
+++ b/app/services/projects/unlink_fork_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class UnlinkForkService < BaseService
     def execute
diff --git a/app/services/projects/update_pages_configuration_service.rb b/app/services/projects/update_pages_configuration_service.rb
index 25017c5cbe3..efbd4c7b323 100644
--- a/app/services/projects/update_pages_configuration_service.rb
+++ b/app/services/projects/update_pages_configuration_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class UpdatePagesConfigurationService < BaseService
     attr_reader :project
diff --git a/app/services/projects/update_pages_service.rb b/app/services/projects/update_pages_service.rb
index 1d8caec9c6f..eb2478be3cf 100644
--- a/app/services/projects/update_pages_service.rb
+++ b/app/services/projects/update_pages_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class UpdatePagesService < BaseService
     InvalidStateError = Class.new(StandardError)
diff --git a/app/services/projects/update_remote_mirror_service.rb b/app/services/projects/update_remote_mirror_service.rb
index 8183a2f26d7..4651f7c4f8f 100644
--- a/app/services/projects/update_remote_mirror_service.rb
+++ b/app/services/projects/update_remote_mirror_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class UpdateRemoteMirrorService < BaseService
     attr_reader :errors
diff --git a/app/services/projects/update_service.rb b/app/services/projects/update_service.rb
index f4fbaacc08b..d3dc11435fe 100644
--- a/app/services/projects/update_service.rb
+++ b/app/services/projects/update_service.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Projects
   class UpdateService < BaseService
     include UpdateVisibilityLevel
diff --git a/changelogs/unreleased/frozen-string-enable-apps-services-inner-more.yml b/changelogs/unreleased/frozen-string-enable-apps-services-inner-more.yml
new file mode 100644
index 00000000000..ea962cf8edc
--- /dev/null
+++ b/changelogs/unreleased/frozen-string-enable-apps-services-inner-more.yml
@@ -0,0 +1,5 @@
+---
+title: Enable more frozen string in app/services/**/*.rb
+merge_request: 20677
+author: gfyoung
+type: performance