Enable frozen string in lib/api and lib/backup

Partially addresses #47424.

Had to make changes to spec files because
stubbing methods on frozen objects is a mess
in RSpec and leads to failures:

https://github.com/rspec/rspec-mocks/issues/1190

changelogs/unreleased/lib-api-frozen-string-enable.yml

+---
+title: Enable frozen string in lib/api and lib/backup
+merge_request:
+author: gfyoung
+type: performance

lib/api/access_requests.rb

+# frozen_string_literal: true
+
 module API
   class AccessRequests < Grape::API
     include PaginationParams

lib/api/api.rb

+# frozen_string_literal: true
+
 module API
   class API < Grape::API
     include APIGuard

lib/api/api_guard.rb

+# frozen_string_literal: true
+
 # Guard API with OAuth 2.0 Access Token
 
 require 'rack/oauth2'

lib/api/applications.rb

+# frozen_string_literal: true
+
 module API
   # External applications API
   class Applications < Grape::API

lib/api/avatar.rb

+# frozen_string_literal: true
+
 module API
   class Avatar < Grape::API
     resource :avatar do

lib/api/award_emoji.rb

+# frozen_string_literal: true
+
 module API
   class AwardEmoji < Grape::API
     include PaginationParams

lib/api/badges.rb

+# frozen_string_literal: true
+
 module API
   class Badges < Grape::API
     include PaginationParams

lib/api/boards.rb

+# frozen_string_literal: true
+
 module API
   class Boards < Grape::API
     include BoardsResponses

lib/api/boards_responses.rb

+# frozen_string_literal: true
+
 module API
   module BoardsResponses
     extend ActiveSupport::Concern

lib/api/branches.rb

+# frozen_string_literal: true
+
 require 'mime/types'
 
 module API

lib/api/broadcast_messages.rb

+# frozen_string_literal: true
+
 module API
   class BroadcastMessages < Grape::API
     include PaginationParams

lib/api/circuit_breakers.rb

+# frozen_string_literal: true
+
 module API
   class CircuitBreakers < Grape::API
     before { authenticated_as_admin! }

lib/api/commit_statuses.rb

+# frozen_string_literal: true
+
 require 'mime/types'
 
 module API

lib/api/commits.rb

+# frozen_string_literal: true
+
 require 'mime/types'
 
 module API

lib/api/custom_attributes_endpoints.rb

+# frozen_string_literal: true
+
 module API
   module CustomAttributesEndpoints
     extend ActiveSupport::Concern

lib/api/deploy_keys.rb

+# frozen_string_literal: true
+
 module API
   class DeployKeys < Grape::API
     include PaginationParams

lib/api/deployments.rb

+# frozen_string_literal: true
+
 module API
   # Deployments RESTful API endpoints
   class Deployments < Grape::API

lib/api/discussions.rb

+# frozen_string_literal: true
+
 module API
   class Discussions < Grape::API
     include PaginationParams

lib/api/entities.rb

+# frozen_string_literal: true
+
 module API
   module Entities
     class WikiPageBasic < Grape::Entity

lib/api/environments.rb

+# frozen_string_literal: true
+
 module API
   # Environments RESTfull API endpoints
   class Environments < Grape::API

lib/api/events.rb

+# frozen_string_literal: true
+
 module API
   class Events < Grape::API
     include PaginationParams

lib/api/features.rb

+# frozen_string_literal: true
+
 module API
   class Features < Grape::API
     before { authenticated_as_admin! }

lib/api/files.rb

+# frozen_string_literal: true
+
 module API
   class Files < Grape::API
     FILE_ENDPOINT_REQUIREMENTS = API::PROJECT_ENDPOINT_REQUIREMENTS.merge(file_path: API::NO_SLASH_URL_PART_REGEX)

lib/api/group_boards.rb

+# frozen_string_literal: true
+
 module API
   class GroupBoards < Grape::API
     include BoardsResponses

lib/api/group_milestones.rb

+# frozen_string_literal: true
+
 module API
   class GroupMilestones < Grape::API
     include MilestoneResponses

lib/api/group_variables.rb

+# frozen_string_literal: true
+
 module API
   class GroupVariables < Grape::API
     include PaginationParams

lib/api/groups.rb

+# frozen_string_literal: true
+
 module API
   class Groups < Grape::API
     include PaginationParams

lib/api/helpers.rb

+# frozen_string_literal: true
+
 module API
   module Helpers
     include Gitlab::Utils
@@ -381,9 +383,10 @@ module API
       # lifted from https://github.com/rails/rails/blob/master/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb#L60
       trace = exception.backtrace
 
-      message = "\n#{exception.class} (#{exception.message}):\n"
+      message = ["\n#{exception.class} (#{exception.message}):\n"]
       message << exception.annoted_source_code.to_s if exception.respond_to?(:annoted_source_code)
       message << "  " << trace.join("\n  ")
+      message = message.join
 
       API.logger.add Logger::FATAL, message
 

lib/api/helpers/badges_helpers.rb

+# frozen_string_literal: true
+
 module API
   module Helpers
     module BadgesHelpers

lib/api/helpers/common_helpers.rb

+# frozen_string_literal: true
+
 module API
   module Helpers
     module CommonHelpers

lib/api/helpers/custom_attributes.rb

+# frozen_string_literal: true
+
 module API
   module Helpers
     module CustomAttributes

lib/api/helpers/custom_validators.rb

+# frozen_string_literal: true
+
 module API
   module Helpers
     module CustomValidators

lib/api/helpers/headers_helpers.rb

+# frozen_string_literal: true
+
 module API
   module Helpers
     module HeadersHelpers

lib/api/helpers/internal_helpers.rb

+# frozen_string_literal: true
+
 module API
   module Helpers
     module InternalHelpers

lib/api/helpers/members_helpers.rb

+# frozen_string_literal: true
+
 # rubocop:disable GitlabSecurity/PublicSend
 
 module API

lib/api/helpers/notes_helpers.rb

+# frozen_string_literal: true
+
 module API
   module Helpers
     module NotesHelpers

lib/api/helpers/pagination.rb

+# frozen_string_literal: true
+
 module API
   module Helpers
     module Pagination

lib/api/helpers/project_snapshots_helpers.rb

+# frozen_string_literal: true
+
 module API
   module Helpers
     module ProjectSnapshotsHelpers

lib/api/helpers/projects_helpers.rb

+# frozen_string_literal: true
+
 module API
   module Helpers
     module ProjectsHelpers

lib/api/helpers/related_resources_helpers.rb

+# frozen_string_literal: true
+
 module API
   module Helpers
     module RelatedResourcesHelpers

lib/api/helpers/runner.rb

+# frozen_string_literal: true
+
 module API
   module Helpers
     module Runner

lib/api/internal.rb

+# frozen_string_literal: true
+
 module API
   # Internal access API
   class Internal < Grape::API

lib/api/issues.rb

+# frozen_string_literal: true
+
 module API
   class Issues < Grape::API
     include PaginationParams

lib/api/job_artifacts.rb

+# frozen_string_literal: true
+
 module API
   class JobArtifacts < Grape::API
     before { authenticate_non_get! }

lib/api/jobs.rb

+# frozen_string_literal: true
+
 module API
   class Jobs < Grape::API
     include PaginationParams

lib/api/keys.rb

+# frozen_string_literal: true
+
 module API
   # Keys API
   class Keys < Grape::API

lib/api/labels.rb

+# frozen_string_literal: true
+
 module API
   class Labels < Grape::API
     include PaginationParams

lib/api/lint.rb

+# frozen_string_literal: true
+
 module API
   class Lint < Grape::API
     namespace :ci do

lib/api/markdown.rb

+# frozen_string_literal: true
+
 module API
   class Markdown < Grape::API
     params do

lib/api/members.rb

+# frozen_string_literal: true
+
 module API
   class Members < Grape::API
     include PaginationParams

lib/api/merge_request_diffs.rb

+# frozen_string_literal: true
+
 module API
   # MergeRequestDiff API
   class MergeRequestDiffs < Grape::API

lib/api/merge_requests.rb

+# frozen_string_literal: true
+
 module API
   class MergeRequests < Grape::API
     include PaginationParams

lib/api/milestone_responses.rb

+# frozen_string_literal: true
+
 module API
   module MilestoneResponses
     extend ActiveSupport::Concern

lib/api/namespaces.rb

+# frozen_string_literal: true
+
 module API
   class Namespaces < Grape::API
     include PaginationParams

lib/api/notes.rb

+# frozen_string_literal: true
+
 module API
   class Notes < Grape::API
     include PaginationParams

lib/api/notification_settings.rb

+# frozen_string_literal: true
+
 module API
   # notification_settings API
   class NotificationSettings < Grape::API

lib/api/pages_domains.rb

+# frozen_string_literal: true
+
 module API
   class PagesDomains < Grape::API
     include PaginationParams

lib/api/pagination_params.rb

+# frozen_string_literal: true
+
 module API
   # Concern for declare pagination params.
   #

lib/api/pipeline_schedules.rb

+# frozen_string_literal: true
+
 module API
   class PipelineSchedules < Grape::API
     include PaginationParams

lib/api/pipelines.rb

+# frozen_string_literal: true
+
 module API
   class Pipelines < Grape::API
     include PaginationParams

lib/api/project_export.rb

+# frozen_string_literal: true
+
 module API
   class ProjectExport < Grape::API
     before do

lib/api/project_hooks.rb

+# frozen_string_literal: true
+
 module API
   class ProjectHooks < Grape::API
     include PaginationParams

lib/api/project_import.rb

+# frozen_string_literal: true
+
 module API
   class ProjectImport < Grape::API
     include PaginationParams

lib/api/project_milestones.rb

+# frozen_string_literal: true
+
 module API
   class ProjectMilestones < Grape::API
     include PaginationParams

lib/api/project_snapshots.rb

+# frozen_string_literal: true
+
 module API
   class ProjectSnapshots < Grape::API
     helpers ::API::Helpers::ProjectSnapshotsHelpers

lib/api/project_snippets.rb

+# frozen_string_literal: true
+
 module API
   class ProjectSnippets < Grape::API
     include PaginationParams

lib/api/projects.rb

+# frozen_string_literal: true
+
 require_dependency 'declarative_policy'
 
 module API

lib/api/projects_relation_builder.rb

+# frozen_string_literal: true
+
 module API
   module ProjectsRelationBuilder
     extend ActiveSupport::Concern

lib/api/protected_branches.rb

+# frozen_string_literal: true
+
 module API
   class ProtectedBranches < Grape::API
     include PaginationParams

lib/api/protected_tags.rb

+# frozen_string_literal: true
+
 module API
   class ProtectedTags < Grape::API
     include PaginationParams

lib/api/repositories.rb

+# frozen_string_literal: true
+
 require 'mime/types'
 
 module API

lib/api/runner.rb

+# frozen_string_literal: true
+
 module API
   class Runner < Grape::API
     helpers ::API::Helpers::Runner

lib/api/runners.rb

+# frozen_string_literal: true
+
 module API
   class Runners < Grape::API
     include PaginationParams

lib/api/scope.rb

+# frozen_string_literal: true
+
 # Encapsulate a scope used for authorization, such as `api`, or `read_user`
 module API
   class Scope

lib/api/search.rb

+# frozen_string_literal: true
+
 module API
   class Search < Grape::API
     include PaginationParams

lib/api/settings.rb

+# frozen_string_literal: true
+
 module API
   class Settings < Grape::API
     before { authenticated_as_admin! }

lib/api/sidekiq_metrics.rb

+# frozen_string_literal: true
+
 require 'sidekiq/api'
 
 module API

lib/api/snippets.rb

+# frozen_string_literal: true
+
 module API
   # Snippets API
   class Snippets < Grape::API

lib/api/subscriptions.rb

+# frozen_string_literal: true
+
 module API
   class Subscriptions < Grape::API
     before { authenticate! }

lib/api/system_hooks.rb

+# frozen_string_literal: true
+
 module API
   class SystemHooks < Grape::API
     include PaginationParams

lib/api/tags.rb

+# frozen_string_literal: true
+
 module API
   class Tags < Grape::API
     include PaginationParams

lib/api/templates.rb

+# frozen_string_literal: true
+
 module API
   class Templates < Grape::API
     include PaginationParams

lib/api/time_tracking_endpoints.rb

+# frozen_string_literal: true
+
 module API
   module TimeTrackingEndpoints
     extend ActiveSupport::Concern

lib/api/todos.rb

+# frozen_string_literal: true
+
 module API
   class Todos < Grape::API
     include PaginationParams

lib/api/triggers.rb

+# frozen_string_literal: true
+
 module API
   class Triggers < Grape::API
     include PaginationParams

lib/api/users.rb

+# frozen_string_literal: true
+
 module API
   class Users < Grape::API
     include PaginationParams

lib/api/variables.rb

+# frozen_string_literal: true
+
 module API
   class Variables < Grape::API
     include PaginationParams

lib/api/version.rb

+# frozen_string_literal: true
+
 module API
   class Version < Grape::API
     before { authenticate! }

lib/api/wikis.rb

+# frozen_string_literal: true
+
 module API
   class Wikis < Grape::API
     helpers do

lib/backup/artifacts.rb

+# frozen_string_literal: true
+
 require 'backup/files'
 
 module Backup

lib/backup/builds.rb

+# frozen_string_literal: true
+
 require 'backup/files'
 
 module Backup

lib/backup/database.rb

+# frozen_string_literal: true
+
 require 'yaml'
 
 module Backup

lib/backup/files.rb

+# frozen_string_literal: true
+
 require 'open3'
 require_relative 'helper'
 

lib/backup/helper.rb

+# frozen_string_literal: true
+
 module Backup
   module Helper
     def access_denied_error(path)

lib/backup/lfs.rb

+# frozen_string_literal: true
+
 require 'backup/files'
 
 module Backup

lib/backup/manager.rb

+# frozen_string_literal: true
+
 module Backup
   class Manager
     ARCHIVES_TO_BACKUP = %w[uploads builds artifacts pages lfs registry].freeze

lib/backup/pages.rb

+# frozen_string_literal: true
+
 require 'backup/files'
 
 module Backup

lib/backup/registry.rb

+# frozen_string_literal: true
+
 require 'backup/files'
 
 module Backup

lib/backup/repository.rb

+# frozen_string_literal: true
+
 require 'yaml'
 
 module Backup