Enable more frozen string in app/services/**/*.rb

Partially addresses #47424.

app/services/lfs/file_transformer.rb

+# 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.

app/services/lfs/lock_file_service.rb

+# frozen_string_literal: true
+
 module Lfs
   class LockFileService < BaseService
     def execute

app/services/lfs/locks_finder_service.rb

+# frozen_string_literal: true
+
 module Lfs
   class LocksFinderService < BaseService
     def execute

app/services/lfs/unlock_file_service.rb

+# frozen_string_literal: true
+
 module Lfs
   class UnlockFileService < BaseService
     def execute

app/services/mattermost/create_team_service.rb

+# frozen_string_literal: true
+
 module Mattermost
   class CreateTeamService < ::BaseService
     def initialize(group, current_user)

app/services/members/approve_access_request_service.rb

+# frozen_string_literal: true
+
 module Members
   class ApproveAccessRequestService < Members::BaseService
     def execute(access_requester, skip_authorization: false, skip_log_audit_event: false)

app/services/members/base_service.rb

+# frozen_string_literal: true
+
 module Members
   class BaseService < ::BaseService
     # current_user - The user that performs the action

app/services/members/create_service.rb

+# frozen_string_literal: true
+
 module Members
   class CreateService < Members::BaseService
     DEFAULT_LIMIT = 100

app/services/members/destroy_service.rb

+# frozen_string_literal: true
+
 module Members
   class DestroyService < Members::BaseService
     def execute(member, skip_authorization: false)

app/services/members/request_access_service.rb

+# frozen_string_literal: true
+
 module Members
   class RequestAccessService < Members::BaseService
     def execute(source)

app/services/members/update_service.rb

+# frozen_string_literal: true
+
 module Members
   class UpdateService < Members::BaseService
     # returns the updated member

app/services/merge_requests/add_todo_when_build_fails_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class AddTodoWhenBuildFailsService < MergeRequests::BaseService
     # Adds a todo to the parent merge_request when a CI build fails

app/services/merge_requests/assign_issues_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class AssignIssuesService < BaseService
     def assignable_issues

app/services/merge_requests/base_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class BaseService < ::IssuableBaseService
     def create_note(merge_request, state = merge_request.state)

app/services/merge_requests/build_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class BuildService < MergeRequests::BaseService
     include Gitlab::Utils::StrongMemoize
@@ -140,7 +142,8 @@ def append_closes_description
       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 @@ def assign_title_from_issue
       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
 

app/services/merge_requests/close_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class CloseService < MergeRequests::BaseService
     def execute(merge_request, commit = nil)

app/services/merge_requests/conflicts/base_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   module Conflicts
     class BaseService

app/services/merge_requests/conflicts/list_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   module Conflicts
     class ListService < MergeRequests::Conflicts::BaseService

app/services/merge_requests/conflicts/resolve_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   module Conflicts
     class ResolveService < MergeRequests::Conflicts::BaseService

app/services/merge_requests/create_from_issue_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class CreateFromIssueService < MergeRequests::CreateService
     def initialize(project, user, params)

app/services/merge_requests/create_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class CreateService < MergeRequests::BaseService
     def execute

app/services/merge_requests/delete_non_latest_diffs_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class DeleteNonLatestDiffsService
     BATCH_SIZE = 10

app/services/merge_requests/ff_merge_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   # MergeService class
   #

app/services/merge_requests/get_urls_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class GetUrlsService < BaseService
     attr_reader :project

app/services/merge_requests/merge_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   # MergeService class
   #

app/services/merge_requests/merge_when_pipeline_succeeds_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class MergeWhenPipelineSucceedsService < MergeRequests::BaseService
     # Marks the passed `merge_request` to be merged when the pipeline succeeds or

app/services/merge_requests/post_merge_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   # PostMergeService class
   #

app/services/merge_requests/rebase_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class RebaseService < MergeRequests::WorkingCopyBaseService
     REBASE_ERROR = 'Rebase failed. Please rebase locally'.freeze

app/services/merge_requests/refresh_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class RefreshService < MergeRequests::BaseService
     def execute(oldrev, newrev, ref)

app/services/merge_requests/reload_diffs_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class ReloadDiffsService
     def initialize(merge_request, current_user)

app/services/merge_requests/reopen_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class ReopenService < MergeRequests::BaseService
     def execute(merge_request)

app/services/merge_requests/resolved_discussion_notification_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class ResolvedDiscussionNotificationService < MergeRequests::BaseService
     def execute(merge_request)

app/services/merge_requests/squash_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class SquashService < MergeRequests::WorkingCopyBaseService
     def execute(merge_request)

app/services/merge_requests/update_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class UpdateService < MergeRequests::BaseService
     def execute(merge_request)

app/services/merge_requests/working_copy_base_service.rb

+# frozen_string_literal: true
+
 module MergeRequests
   class WorkingCopyBaseService < MergeRequests::BaseService
     attr_reader :merge_request

app/services/milestones/base_service.rb

+# frozen_string_literal: true
+
 module Milestones
   class BaseService < ::BaseService
     # Parent can either a group or a project

app/services/milestones/close_service.rb

+# frozen_string_literal: true
+
 module Milestones
   class CloseService < Milestones::BaseService
     def execute(milestone)

app/services/milestones/create_service.rb

+# frozen_string_literal: true
+
 module Milestones
   class CreateService < Milestones::BaseService
     def execute

app/services/milestones/destroy_service.rb

+# frozen_string_literal: true
+
 module Milestones
   class DestroyService < Milestones::BaseService
     def execute(milestone)

app/services/milestones/promote_service.rb

+# frozen_string_literal: true
+
 module Milestones
   class PromoteService < Milestones::BaseService
     PromoteMilestoneError = Class.new(StandardError)

app/services/milestones/reopen_service.rb

+# frozen_string_literal: true
+
 module Milestones
   class ReopenService < Milestones::BaseService
     def execute(milestone)

app/services/milestones/update_service.rb

+# frozen_string_literal: true
+
 module Milestones
   class UpdateService < Milestones::BaseService
     def execute(milestone)

app/services/notes/build_service.rb

+# frozen_string_literal: true
+
 module Notes
   class BuildService < ::BaseService
     def execute

app/services/notes/create_service.rb

+# frozen_string_literal: true
+
 module Notes
   class CreateService < ::BaseService
     def execute

app/services/notes/destroy_service.rb

+# frozen_string_literal: true
+
 module Notes
   class DestroyService < BaseService
     def execute(note)

app/services/notes/post_process_service.rb

+# frozen_string_literal: true
+
 module Notes
   class PostProcessService
     attr_accessor :note

app/services/notes/quick_actions_service.rb

+# frozen_string_literal: true
+
 module Notes
   class QuickActionsService < BaseService
     UPDATE_SERVICES = {

app/services/notes/render_service.rb

+# frozen_string_literal: true
+
 module Notes
   class RenderService < BaseRenderer
     # Renders a collection of Note instances.

app/services/notes/resolve_service.rb

+# frozen_string_literal: true
+
 module Notes
   class ResolveService < ::BaseService
     def execute(note)

app/services/notes/update_service.rb

+# frozen_string_literal: true
+
 module Notes
   class UpdateService < BaseService
     def execute(note)

app/services/projects/after_import_service.rb

+# frozen_string_literal: true
+
 module Projects
   class AfterImportService
     RESERVED_REF_PREFIXES = Repository::RESERVED_REFS_NAMES.map { |n| File.join('refs', n, '/') }

app/services/projects/autocomplete_service.rb

+# frozen_string_literal: true
+
 module Projects
   class AutocompleteService < BaseService
     def issues

app/services/projects/base_move_relations_service.rb

+# frozen_string_literal: true
+
 module Projects
   class BaseMoveRelationsService < BaseService
     attr_reader :source_project

app/services/projects/batch_count_service.rb

+# 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.

app/services/projects/batch_forks_count_service.rb

+# 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

app/services/projects/batch_open_issues_count_service.rb

+# 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

app/services/projects/count_service.rb

+# frozen_string_literal: true
+
 module Projects
   # Base class for the various service classes that count project data (e.g.
   # issues or forks).

app/services/projects/create_from_template_service.rb

+# frozen_string_literal: true
+
 module Projects
   class CreateFromTemplateService < BaseService
     def initialize(user, params)

app/services/projects/create_service.rb

+# frozen_string_literal: true
+
 module Projects
   class CreateService < BaseService
     def initialize(user, params)

app/services/projects/destroy_service.rb

+# frozen_string_literal: true
+
 module Projects
   class DestroyService < BaseService
     include Gitlab::ShellAdapter

app/services/projects/download_service.rb

+# frozen_string_literal: true
+
 module Projects
   class DownloadService < BaseService
     WHITELIST = [

app/services/projects/enable_deploy_key_service.rb

+# frozen_string_literal: true
+
 module Projects
   class EnableDeployKeyService < BaseService
     def execute

app/services/projects/fork_service.rb

+# frozen_string_literal: true
+
 module Projects
   class ForkService < BaseService
     def execute(fork_to_project = nil)

app/services/projects/forks_count_service.rb

+# frozen_string_literal: true
+
 module Projects
   # Service class for getting and caching the number of forks of a project.
   class ForksCountService < Projects::CountService

app/services/projects/gitlab_projects_import_service.rb

+# 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.

app/services/projects/group_links/create_service.rb

+# frozen_string_literal: true
+
 module Projects
   module GroupLinks
     class CreateService < BaseService

app/services/projects/group_links/destroy_service.rb

+# frozen_string_literal: true
+
 module Projects
   module GroupLinks
     class DestroyService < BaseService

app/services/projects/hashed_storage/migrate_attachments_service.rb

+# frozen_string_literal: true
+
 module Projects
   module HashedStorage
     AttachmentMigrationError = Class.new(StandardError)

app/services/projects/hashed_storage/migrate_repository_service.rb

+# frozen_string_literal: true
+
 module Projects
   module HashedStorage
     class MigrateRepositoryService < BaseService

app/services/projects/hashed_storage_migration_service.rb

+# frozen_string_literal: true
+
 module Projects
   class HashedStorageMigrationService < BaseService
     attr_reader :logger

app/services/projects/housekeeping_service.rb

+# frozen_string_literal: true
+
 # Projects::HousekeepingService class
 #
 # Used for git housekeeping

app/services/projects/import_export/export_service.rb

+# frozen_string_literal: true
+
 module Projects
   module ImportExport
     class ExportService < BaseService

app/services/projects/import_service.rb

+# frozen_string_literal: true
+
 module Projects
   class ImportService < BaseService
     include Gitlab::ShellAdapter

app/services/projects/lfs_pointers/lfs_download_link_list_service.rb

+# frozen_string_literal: true
+
 # This service lists the download link from a remote source based on the
 # oids provided
 module Projects

app/services/projects/lfs_pointers/lfs_download_service.rb

+# frozen_string_literal: true
+
 # This service downloads and links lfs objects from a remote URL
 module Projects
   module LfsPointers

app/services/projects/lfs_pointers/lfs_import_service.rb

+# 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.

app/services/projects/lfs_pointers/lfs_link_service.rb

+# frozen_string_literal: true
+
 # Given a list of oids, this services links the existent Lfs Objects to the project
 module Projects
   module LfsPointers

app/services/projects/lfs_pointers/lfs_list_service.rb

+# frozen_string_literal: true
+
 # This service list all existent Lfs objects in a repository
 module Projects
   module LfsPointers

app/services/projects/move_access_service.rb

+# frozen_string_literal: true
+
 module Projects
   class MoveAccessService < BaseMoveRelationsService
     def execute(source_project, remove_remaining_elements: true)

app/services/projects/move_deploy_keys_projects_service.rb

+# frozen_string_literal: true
+
 module Projects
   class MoveDeployKeysProjectsService < BaseMoveRelationsService
     def execute(source_project, remove_remaining_elements: true)

app/services/projects/move_forks_service.rb

+# frozen_string_literal: true
+
 module Projects
   class MoveForksService < BaseMoveRelationsService
     def execute(source_project, remove_remaining_elements: true)

app/services/projects/move_lfs_objects_projects_service.rb

+# frozen_string_literal: true
+
 module Projects
   class MoveLfsObjectsProjectsService < BaseMoveRelationsService
     def execute(source_project, remove_remaining_elements: true)

app/services/projects/move_notification_settings_service.rb

+# frozen_string_literal: true
+
 module Projects
   class MoveNotificationSettingsService < BaseMoveRelationsService
     def execute(source_project, remove_remaining_elements: true)

app/services/projects/move_project_authorizations_service.rb

+# 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

app/services/projects/move_project_group_links_service.rb

+# 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

app/services/projects/move_project_members_service.rb

+# frozen_string_literal: true
+