diff --git a/.rubocop.yml b/.rubocop.yml
index d7c5eee3..369a4037 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -152,6 +152,9 @@ Style/ExponentialNotation:
 Style/FormatStringToken:
   Enabled: false
 
+Style/FrozenStringLiteralComment:
+  EnforcedStyle: always_true
+
 Style/GuardClause:
   Enabled: false
 
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index d4f4309b..9907ef22 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -49,13 +49,6 @@ Style/OptionalBooleanParameter:
     - 'app/jobs/analyze_change_job.rb'
     - 'app/models/application_record.rb'
 
-# Offense count: 67
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: when_needed, always, never
-Style/FrozenStringLiteralComment:
-  Enabled: false
-
 # Offense count: 4
 # Cop supports --auto-correct.
 # Configuration parameters: EnforcedStyle, SupportedStyles, UseHashRocketsWithSymbolValues, PreferHashRocketsForNonAlnumEndingSymbols.
diff --git a/Gemfile b/Gemfile
index 3c98873a..ceb8299c 100644
--- a/Gemfile
+++ b/Gemfile
@@ -35,6 +35,9 @@ gem 'hiredis'
 gem 'sentry-ruby', '~> 5.26.0'
 gem 'sentry-rails', '~> 5.26.0'
 
+# We don't make direct use of this; it's really here to suppress a warning about upcoming changes to bundled gems.
+gem "pstore", "~> 0.2.0"
+
 # See https://github.com/rails/execjs#readme for more supported runtimes
 # gem 'therubyracer', platforms: :ruby
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
diff --git a/Gemfile.lock b/Gemfile.lock
index 15885cd9..db250f6a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -268,6 +268,7 @@ GEM
       method_source (~> 1.0)
     pry-rails (0.3.11)
       pry (>= 0.13.0)
+    pstore (0.2.0)
     psych (5.2.6)
       date
       stringio
@@ -468,6 +469,7 @@ DEPENDENCIES
   pg (~> 1.6)
   postmark-rails
   pry-rails
+  pstore (~> 0.2.0)
   puma (~> 7.1)
   pundit (~> 2.5.2)
   rack-brotli
diff --git a/Rakefile b/Rakefile
index e85f9139..488c551f 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Add your own tasks in files placed in lib/tasks ending in .rake,
 # for example lib/tasks/capistrano.rake, and they will automatically be available to Rake.
 
diff --git a/app/channels/application_cable/channel.rb b/app/channels/application_cable/channel.rb
index d6726972..9aec2305 100644
--- a/app/channels/application_cable/channel.rb
+++ b/app/channels/application_cable/channel.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ApplicationCable
   class Channel < ActionCable::Channel::Base
   end
diff --git a/app/channels/application_cable/connection.rb b/app/channels/application_cable/connection.rb
index 0ff5442f..8d6c2a1b 100644
--- a/app/channels/application_cable/connection.rb
+++ b/app/channels/application_cable/connection.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ApplicationCable
   class Connection < ActionCable::Connection::Base
   end
diff --git a/app/controllers/admin/users_controller.rb b/app/controllers/admin/users_controller.rb
index 3d74aff1..9e4daebe 100644
--- a/app/controllers/admin/users_controller.rb
+++ b/app/controllers/admin/users_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class UsersController < ApplicationController
     before_action :authenticate_user!
diff --git a/app/controllers/admin_controller.rb b/app/controllers/admin_controller.rb
index 34a8f883..0af0378b 100644
--- a/app/controllers/admin_controller.rb
+++ b/app/controllers/admin_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AdminController < ApplicationController
   protect_from_forgery with: :exception
 
diff --git a/app/controllers/api/v0/annotations_controller.rb b/app/controllers/api/v0/annotations_controller.rb
index f08960b5..013fc9f7 100644
--- a/app/controllers/api/v0/annotations_controller.rb
+++ b/app/controllers/api/v0/annotations_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Api::V0::AnnotationsController < Api::V0::ApiController
   include SortingConcern
   include BlockedParamsConcern
diff --git a/app/controllers/api/v0/api_controller.rb b/app/controllers/api/v0/api_controller.rb
index 87cf3fd1..04fa62d5 100644
--- a/app/controllers/api/v0/api_controller.rb
+++ b/app/controllers/api/v0/api_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Api::V0::ApiController < ApplicationController
   skip_forgery_protection
 
diff --git a/app/controllers/api/v0/changes_controller.rb b/app/controllers/api/v0/changes_controller.rb
index 1acdd803..4566cdc0 100644
--- a/app/controllers/api/v0/changes_controller.rb
+++ b/app/controllers/api/v0/changes_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Api::V0::ChangesController < Api::V0::ApiController
   include SortingConcern
   include BlockedParamsConcern
diff --git a/app/controllers/api/v0/diff_controller.rb b/app/controllers/api/v0/diff_controller.rb
index 85b8ff51..287441f6 100644
--- a/app/controllers/api/v0/diff_controller.rb
+++ b/app/controllers/api/v0/diff_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Api::V0::DiffController < Api::V0::ApiController
   def show
     ensure_diffable
diff --git a/app/controllers/api/v0/imports_controller.rb b/app/controllers/api/v0/imports_controller.rb
index 35aae8f8..61b8a4c8 100644
--- a/app/controllers/api/v0/imports_controller.rb
+++ b/app/controllers/api/v0/imports_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Api::V0::ImportsController < Api::V0::ApiController
   before_action { authorize :api, :import? }
 
diff --git a/app/controllers/api/v0/maintainers_controller.rb b/app/controllers/api/v0/maintainers_controller.rb
index be080a1f..9e612f6f 100644
--- a/app/controllers/api/v0/maintainers_controller.rb
+++ b/app/controllers/api/v0/maintainers_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Api::V0::MaintainersController < Api::V0::ApiController
   include SortingConcern
 
diff --git a/app/controllers/api/v0/pages_controller.rb b/app/controllers/api/v0/pages_controller.rb
index 613a37a1..d6d07ca7 100644
--- a/app/controllers/api/v0/pages_controller.rb
+++ b/app/controllers/api/v0/pages_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Api::V0::PagesController < Api::V0::ApiController
   include SortingConcern
   include BlockedParamsConcern
diff --git a/app/controllers/api/v0/tags_controller.rb b/app/controllers/api/v0/tags_controller.rb
index f0a2d93f..80025073 100644
--- a/app/controllers/api/v0/tags_controller.rb
+++ b/app/controllers/api/v0/tags_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Api::V0::TagsController < Api::V0::ApiController
   include SortingConcern
 
diff --git a/app/controllers/api/v0/urls_controller.rb b/app/controllers/api/v0/urls_controller.rb
index bae56a7f..0d75bd95 100644
--- a/app/controllers/api/v0/urls_controller.rb
+++ b/app/controllers/api/v0/urls_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Api::V0::UrlsController < Api::V0::ApiController
   before_action(except: [:index, :show]) { authorize(:api, :import?) }
 
diff --git a/app/controllers/api/v0/versions_controller.rb b/app/controllers/api/v0/versions_controller.rb
index c8d7d8b7..2aa2028a 100644
--- a/app/controllers/api/v0/versions_controller.rb
+++ b/app/controllers/api/v0/versions_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Api::V0::VersionsController < Api::V0::ApiController
   include SortingConcern
   include BlockedParamsConcern
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index a6403c47..9fabb63f 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApplicationController < ActionController::Base
   include Pundit::Authorization
   include SameOriginSessionsConcern
diff --git a/app/controllers/concerns/blocked_params_concern.rb b/app/controllers/concerns/blocked_params_concern.rb
index da29d13e..a1c6673f 100644
--- a/app/controllers/concerns/blocked_params_concern.rb
+++ b/app/controllers/concerns/blocked_params_concern.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Block unauthenticated requests that use certain params with a 403 (Forbidden)
 # error. This can be used to prevent abuse of options that may cause expensive
 # operations.
diff --git a/app/controllers/concerns/paging_concern.rb b/app/controllers/concerns/paging_concern.rb
index c7f59914..4fcbd857 100644
--- a/app/controllers/concerns/paging_concern.rb
+++ b/app/controllers/concerns/paging_concern.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module PagingConcern
   extend ActiveSupport::Concern
 
diff --git a/app/controllers/concerns/same_origin_sessions_concern.rb b/app/controllers/concerns/same_origin_sessions_concern.rb
index d027c5af..ca4bd4db 100644
--- a/app/controllers/concerns/same_origin_sessions_concern.rb
+++ b/app/controllers/concerns/same_origin_sessions_concern.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Make sessions available only to requests from the same host as the server.
 #
 # This means sessions work for people browsing this site directly, but not for
diff --git a/app/controllers/concerns/sorting_concern.rb b/app/controllers/concerns/sorting_concern.rb
index 28fac8be..0fe87941 100644
--- a/app/controllers/concerns/sorting_concern.rb
+++ b/app/controllers/concerns/sorting_concern.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module SortingConcern
   extend ActiveSupport::Concern
 
diff --git a/app/controllers/healthcheck_controller.rb b/app/controllers/healthcheck_controller.rb
index 30040780..cfeed412 100644
--- a/app/controllers/healthcheck_controller.rb
+++ b/app/controllers/healthcheck_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class HealthcheckController < ApplicationController
   def index
     # Succeed if the app is running, but provide additional
diff --git a/app/controllers/home_controller.rb b/app/controllers/home_controller.rb
index ab78cb62..3352b9cb 100644
--- a/app/controllers/home_controller.rb
+++ b/app/controllers/home_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class HomeController < ApplicationController
   def index
     render
diff --git a/app/controllers/users/registrations_controller.rb b/app/controllers/users/registrations_controller.rb
index 466215eb..13d755b8 100644
--- a/app/controllers/users/registrations_controller.rb
+++ b/app/controllers/users/registrations_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Users::RegistrationsController < Devise::RegistrationsController
   # before_action :configure_sign_up_params, only: [:create]
   # before_action :configure_account_update_params, only: [:update]
diff --git a/app/controllers/users/sessions_controller.rb b/app/controllers/users/sessions_controller.rb
index 7e499f17..f7e5ed82 100644
--- a/app/controllers/users/sessions_controller.rb
+++ b/app/controllers/users/sessions_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Users::SessionsController < Devise::SessionsController
   skip_forgery_protection
 
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index de6be794..15b06f0f 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 module ApplicationHelper
 end
diff --git a/app/jobs/analyze_change_job.rb b/app/jobs/analyze_change_job.rb
index 13805776..30fe132e 100644
--- a/app/jobs/analyze_change_job.rb
+++ b/app/jobs/analyze_change_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # NOTE: THIS JOB IS NOT IN ACTIVE USE.
 # The use cases it served were better solved by the task-sheets project
 # (https://github.com/edgi-govdata-archiving/web-monitoring-task-sheets).
diff --git a/app/jobs/application_job.rb b/app/jobs/application_job.rb
index a009ace5..d92ffddc 100644
--- a/app/jobs/application_job.rb
+++ b/app/jobs/application_job.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class ApplicationJob < ActiveJob::Base
 end
diff --git a/app/jobs/import_versions_job.rb b/app/jobs/import_versions_job.rb
index e549766d..b19e9092 100644
--- a/app/jobs/import_versions_job.rb
+++ b/app/jobs/import_versions_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ImportVersionsJob < ApplicationJob
   queue_as :import
 
diff --git a/app/lib/data_helpers.rb b/app/lib/data_helpers.rb
index 96a77bd3..cd9ad3b8 100644
--- a/app/lib/data_helpers.rb
+++ b/app/lib/data_helpers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Tools for working with database data. These are mostly used in rake tasks and migrations.
 module DataHelpers
   class ProgressLogger
diff --git a/app/lib/numeric_interval.rb b/app/lib/numeric_interval.rb
index ce6d5c5c..890cd81d 100644
--- a/app/lib/numeric_interval.rb
+++ b/app/lib/numeric_interval.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class NumericInterval
   attr_reader :start, :start_open
   attr_reader :end, :end_open
diff --git a/app/lib/surt.rb b/app/lib/surt.rb
index a1966667..dfd66d13 100644
--- a/app/lib/surt.rb
+++ b/app/lib/surt.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'addressable/uri'
 
 # Tools for canonicalizing and formatting URLs according to the Internet
diff --git a/app/lib/surt/canonicalize.rb b/app/lib/surt/canonicalize.rb
index 25b21141..c291c383 100644
--- a/app/lib/surt/canonicalize.rb
+++ b/app/lib/surt/canonicalize.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'addressable/uri'
 
 module Surt::Canonicalize
@@ -83,7 +85,7 @@ module Surt::Canonicalize
   #  test fails if we just use Addressable's standard set. Maybe drop this?
   #  Also validate against the original Java version:
   #  https://github.com/iipc/webarchive-commons/blob/5fb641b7ff3c63ade0eb39782fc8b1982ea27330/src/main/java/org/archive/url/BasicURLCanonicalizer.java#L219-L275
-  URL_SPECIAL_CHARACTERS = '!"$&\'()*+,-./:;<=>?@[\]^_`{|}~'.freeze
+  URL_SPECIAL_CHARACTERS = '!"$&\'()*+,-./:;<=>?@[\]^_`{|}~'
   SAFE_CHARACTERS = "0-9a-zA-Z#{Regexp.escape(URL_SPECIAL_CHARACTERS)}".freeze
 
   # Canonicalize a URL. This is the normal entrypoint to this module.
diff --git a/app/lib/surt/format.rb b/app/lib/surt/format.rb
index b2a024b2..d8ad270a 100644
--- a/app/lib/surt/format.rb
+++ b/app/lib/surt/format.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Surt::Format
   DEFAULT_OPTIONS = {
     include_scheme: false,
diff --git a/app/mailers/application_mailer.rb b/app/mailers/application_mailer.rb
index 286b2239..d84cb6e7 100644
--- a/app/mailers/application_mailer.rb
+++ b/app/mailers/application_mailer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApplicationMailer < ActionMailer::Base
   default from: 'from@example.com'
   layout 'mailer'
diff --git a/app/mailers/invitation_mailer.rb b/app/mailers/invitation_mailer.rb
index f6bbba7e..f94b4c98 100644
--- a/app/mailers/invitation_mailer.rb
+++ b/app/mailers/invitation_mailer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class InvitationMailer < ApplicationMailer
   def invitation_email(invitation)
     @invitation = invitation
diff --git a/app/models/annotation.rb b/app/models/annotation.rb
index 66af502a..44bd56ef 100644
--- a/app/models/annotation.rb
+++ b/app/models/annotation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Annotation < ApplicationRecord
   include UuidPrimaryKey
 
diff --git a/app/models/application_record.rb b/app/models/application_record.rb
index e1e6f8bd..87f3362a 100644
--- a/app/models/application_record.rb
+++ b/app/models/application_record.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApplicationRecord < ActiveRecord::Base
   self.abstract_class = true
 
diff --git a/app/models/change.rb b/app/models/change.rb
index 8b12c473..b4769af3 100644
--- a/app/models/change.rb
+++ b/app/models/change.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Change < ApplicationRecord
   include UuidPrimaryKey
 
diff --git a/app/models/concerns/simple_title.rb b/app/models/concerns/simple_title.rb
index 6a4555f0..3ce7cacf 100644
--- a/app/models/concerns/simple_title.rb
+++ b/app/models/concerns/simple_title.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module SimpleTitle
   extend ActiveSupport::Concern
 
diff --git a/app/models/concerns/taggable.rb b/app/models/concerns/taggable.rb
index fb3119e2..c1b79af7 100644
--- a/app/models/concerns/taggable.rb
+++ b/app/models/concerns/taggable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Taggable
   extend ActiveSupport::Concern
 
diff --git a/app/models/concerns/uuid_primary_key.rb b/app/models/concerns/uuid_primary_key.rb
index e59bb32a..d3eb8324 100644
--- a/app/models/concerns/uuid_primary_key.rb
+++ b/app/models/concerns/uuid_primary_key.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module UuidPrimaryKey
   extend ActiveSupport::Concern
 
diff --git a/app/models/import.rb b/app/models/import.rb
index 9791a3ae..8e792e01 100644
--- a/app/models/import.rb
+++ b/app/models/import.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Import < ApplicationRecord
   belongs_to :user
   enum :status, [:pending, :processing, :complete]
diff --git a/app/models/invitation.rb b/app/models/invitation.rb
index 19abc731..90f435fb 100644
--- a/app/models/invitation.rb
+++ b/app/models/invitation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Invitation < ApplicationRecord
   EXPIRATION_DAYS = 14
 
diff --git a/app/models/maintainer.rb b/app/models/maintainer.rb
index 1046e38c..e1880daf 100644
--- a/app/models/maintainer.rb
+++ b/app/models/maintainer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Maintainer represents an organization that maintains some web pages. It has
 # a name and an optional link to a parent maintainer so there can be a
 # hierarchical relationship (e.g. an office of a department of an organization)
diff --git a/app/models/maintainership.rb b/app/models/maintainership.rb
index 57f28a8d..da550188 100644
--- a/app/models/maintainership.rb
+++ b/app/models/maintainership.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Maintainership < ApplicationRecord
   belongs_to :maintainer, foreign_key: :maintainer_uuid
   belongs_to :page, foreign_key: :page_uuid
diff --git a/app/models/merged_page.rb b/app/models/merged_page.rb
index 53856348..3c1793c3 100644
--- a/app/models/merged_page.rb
+++ b/app/models/merged_page.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # MergedPage keeps track of pages that were merged into others so we can
 # support old links by redirecting to the page they were merged into.
 # - The primary key is the ID of the page that was merged and removed
diff --git a/app/models/page.rb b/app/models/page.rb
index 2d53e70e..98622a7a 100644
--- a/app/models/page.rb
+++ b/app/models/page.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Page < ApplicationRecord
   include UuidPrimaryKey
   include Taggable
diff --git a/app/models/page_url.rb b/app/models/page_url.rb
index aa24943c..866bcdb8 100644
--- a/app/models/page_url.rb
+++ b/app/models/page_url.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # PageUrl is a critical part of each Page model. Pages do not represent a
 # single URL -- pages are often reachable from multiple URLs (sometimes at
 # the same time; sometimes because a page moves over time) and different
diff --git a/app/models/tag.rb b/app/models/tag.rb
index f980bc8a..8961f09e 100644
--- a/app/models/tag.rb
+++ b/app/models/tag.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Tag < ApplicationRecord
   include UuidPrimaryKey
 
diff --git a/app/models/tagging.rb b/app/models/tagging.rb
index c55ded66..33f26350 100644
--- a/app/models/tagging.rb
+++ b/app/models/tagging.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Tagging < ApplicationRecord
   belongs_to :taggable, polymorphic: true, foreign_key: :taggable_uuid
   belongs_to :tag, inverse_of: :taggings, foreign_key: :tag_uuid
diff --git a/app/models/user.rb b/app/models/user.rb
index 62816186..fdc207c4 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 class User < ApplicationRecord
   PERMISSIONS = [
-    VIEW_PERMISSION = 'view'.freeze,
-    ANNOTATE_PERMISSION = 'annotate'.freeze,
-    IMPORT_PERMISSION = 'import'.freeze,
-    MANAGE_USERS_PERMISSION = 'manage_users'.freeze
+    VIEW_PERMISSION = 'view',
+    ANNOTATE_PERMISSION = 'annotate',
+    IMPORT_PERMISSION = 'import',
+    MANAGE_USERS_PERMISSION = 'manage_users'
   ].freeze
 
   PERMISSION_DESCRIPTIONS = {
diff --git a/app/models/version.rb b/app/models/version.rb
index 09d10528..326fb602 100644
--- a/app/models/version.rb
+++ b/app/models/version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Version < ApplicationRecord
   include UuidPrimaryKey
   include SimpleTitle
diff --git a/app/policies/admin_policy.rb b/app/policies/admin_policy.rb
index e166cdfe..cf397481 100644
--- a/app/policies/admin_policy.rb
+++ b/app/policies/admin_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AdminPolicy < ApplicationPolicy
   def any?
     user.can_manage_users?
diff --git a/app/policies/api_policy.rb b/app/policies/api_policy.rb
index 9a6f3346..9302e8a1 100644
--- a/app/policies/api_policy.rb
+++ b/app/policies/api_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApiPolicy < ApplicationPolicy
   def view?
     Rails.configuration.allow_public_view || (user.present? && user.can_view?)
diff --git a/app/policies/application_policy.rb b/app/policies/application_policy.rb
index eefe976c..50f2d7c6 100644
--- a/app/policies/application_policy.rb
+++ b/app/policies/application_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApplicationPolicy
   attr_reader :user, :record
 
diff --git a/app/validators/contains_only_validator.rb b/app/validators/contains_only_validator.rb
index 00081686..0d8c2f36 100644
--- a/app/validators/contains_only_validator.rb
+++ b/app/validators/contains_only_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ContainsOnlyValidator < ActiveModel::EachValidator
   def validate_each(record, attribute, value)
     unless value.is_a?(Array)
diff --git a/bin/bundle b/bin/bundle
index f19acf5b..2dbb7176 100755
--- a/bin/bundle
+++ b/bin/bundle
@@ -1,3 +1,5 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
+
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
 load Gem.bin_path('bundler', 'bundle')
diff --git a/bin/dev b/bin/dev
index 52088a38..39257831 100755
--- a/bin/dev
+++ b/bin/dev
@@ -1,2 +1,4 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
+
 exec './bin/rails', 'server', *ARGV
diff --git a/bin/lint b/bin/lint
index ec500a17..1126e666 100755
--- a/bin/lint
+++ b/bin/lint
@@ -1,4 +1,6 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
+
 require 'fileutils'
 require 'optparse'
 include FileUtils # rubocop:disable Style/MixinUsage
diff --git a/bin/rails b/bin/rails
index 07396602..a31728ab 100755
--- a/bin/rails
+++ b/bin/rails
@@ -1,4 +1,6 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
+
 APP_PATH = File.expand_path('../config/application', __dir__)
 require_relative '../config/boot'
 require 'rails/commands'
diff --git a/bin/rake b/bin/rake
index 17240489..c1999550 100755
--- a/bin/rake
+++ b/bin/rake
@@ -1,4 +1,6 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
+
 require_relative '../config/boot'
 require 'rake'
 Rake.application.run
diff --git a/bin/setup b/bin/setup
index c52d4761..bfeb79b6 100755
--- a/bin/setup
+++ b/bin/setup
@@ -1,8 +1,10 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
+
 require 'fileutils'
 
 APP_ROOT = File.expand_path('..', __dir__)
-APP_NAME = 'webpage-versions-db'.freeze
+APP_NAME = 'webpage-versions-db'
 
 def system!(*)
   system(*, exception: true)
diff --git a/bin/thrust b/bin/thrust
index eea4a0a2..78bfb7c1 100755
--- a/bin/thrust
+++ b/bin/thrust
@@ -1,4 +1,6 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
+
 require 'rubygems'
 require 'bundler/setup'
 
diff --git a/bin/update b/bin/update
index 05737c27..73dd1c3f 100755
--- a/bin/update
+++ b/bin/update
@@ -1,4 +1,6 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
+
 require 'fileutils'
 include FileUtils # rubocop:disable Style/MixinUsage
 
diff --git a/bin/yarn b/bin/yarn
index 81499bff..72de7857 100755
--- a/bin/yarn
+++ b/bin/yarn
@@ -1,4 +1,6 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
+
 require 'pathname'
 
 APP_ROOT = File.expand_path('..', __dir__)
diff --git a/config.ru b/config.ru
index ad1fbf29..6dc83218 100644
--- a/config.ru
+++ b/config.ru
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This file is used by Rack-based servers to start the application.
 
 require_relative 'config/environment'
diff --git a/db/migrate/20170302233652_devise_create_users.rb b/db/migrate/20170302233652_devise_create_users.rb
index e43828f1..0837a1c2 100644
--- a/db/migrate/20170302233652_devise_create_users.rb
+++ b/db/migrate/20170302233652_devise_create_users.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DeviseCreateUsers < ActiveRecord::Migration[5.0]
   def change
     create_table :users do |t|
diff --git a/db/migrate/20170303213937_create_invitations.rb b/db/migrate/20170303213937_create_invitations.rb
index 4581b37b..19e2b373 100644
--- a/db/migrate/20170303213937_create_invitations.rb
+++ b/db/migrate/20170303213937_create_invitations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateInvitations < ActiveRecord::Migration[5.0]
   def change
     create_table :invitations do |t|
diff --git a/db/migrate/20170313192244_create_new_db_schema_with_generic_page_version_change_annotation.rb b/db/migrate/20170313192244_create_new_db_schema_with_generic_page_version_change_annotation.rb
index 413d8147..af464c1d 100644
--- a/db/migrate/20170313192244_create_new_db_schema_with_generic_page_version_change_annotation.rb
+++ b/db/migrate/20170313192244_create_new_db_schema_with_generic_page_version_change_annotation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateNewDbSchemaWithGenericPageVersionChangeAnnotation < ActiveRecord::Migration[5.0]
   def change
     # Since 9.4, PostgreSQL recommends using `pgcrypto`'s `gen_random_uuid()`
diff --git a/db/migrate/20170425211418_add_missing_page_schemes.rb b/db/migrate/20170425211418_add_missing_page_schemes.rb
index c5822a1a..ede71694 100644
--- a/db/migrate/20170425211418_add_missing_page_schemes.rb
+++ b/db/migrate/20170425211418_add_missing_page_schemes.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddMissingPageSchemes < ActiveRecord::Migration[5.0]
   def up
     Page.where("url NOT LIKE 'http://%' AND url NOT LIKE 'https://%' AND url NOT LIKE 'ftp://%'").each(&:save)
diff --git a/db/migrate/20170429002015_create_imports.rb b/db/migrate/20170429002015_create_imports.rb
index ec4139aa..44a44182 100644
--- a/db/migrate/20170429002015_create_imports.rb
+++ b/db/migrate/20170429002015_create_imports.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateImports < ActiveRecord::Migration[5.0]
   def change
     create_table :imports do |t|
diff --git a/db/migrate/20170508221326_add_indexes_for_importing.rb b/db/migrate/20170508221326_add_indexes_for_importing.rb
index 250bfc3c..b84e38e6 100644
--- a/db/migrate/20170508221326_add_indexes_for_importing.rb
+++ b/db/migrate/20170508221326_add_indexes_for_importing.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddIndexesForImporting < ActiveRecord::Migration[5.0]
   def change
     add_index :versions, :capture_time
diff --git a/db/migrate/20170517222310_change_annotation_author_to_not_null.rb b/db/migrate/20170517222310_change_annotation_author_to_not_null.rb
index aaada77a..d165dfbb 100644
--- a/db/migrate/20170517222310_change_annotation_author_to_not_null.rb
+++ b/db/migrate/20170517222310_change_annotation_author_to_not_null.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ChangeAnnotationAuthorToNotNull < ActiveRecord::Migration[5.1]
   def do_sql(*args)
     expression = ActiveRecord::Base.send :sanitize_sql, args
diff --git a/db/migrate/20170713234650_set_change_priority_default_to_null.rb b/db/migrate/20170713234650_set_change_priority_default_to_null.rb
index 2dfa07a8..60b7eaa6 100644
--- a/db/migrate/20170713234650_set_change_priority_default_to_null.rb
+++ b/db/migrate/20170713234650_set_change_priority_default_to_null.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class SetChangePriorityDefaultToNull < ActiveRecord::Migration[5.1]
   def do_sql(*args)
     expression = ActiveRecord::Base.send :sanitize_sql, args
diff --git a/db/migrate/20170717072416_add_significance_to_change.rb b/db/migrate/20170717072416_add_significance_to_change.rb
index 8382b678..b98add25 100644
--- a/db/migrate/20170717072416_add_significance_to_change.rb
+++ b/db/migrate/20170717072416_add_significance_to_change.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddSignificanceToChange < ActiveRecord::Migration[5.1]
   def change
     add_column(:changes, :significance, :float, null: true, default: nil)
diff --git a/db/migrate/20170801192038_add_update_behavior_to_import.rb b/db/migrate/20170801192038_add_update_behavior_to_import.rb
index 2a462459..ba773dc1 100644
--- a/db/migrate/20170801192038_add_update_behavior_to_import.rb
+++ b/db/migrate/20170801192038_add_update_behavior_to_import.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddUpdateBehaviorToImport < ActiveRecord::Migration[5.1]
   def change
     add_column(:imports, :update_behavior, :integer, default: 0, null: false)
diff --git a/db/migrate/20170909151007_add_title_to_versions.rb b/db/migrate/20170909151007_add_title_to_versions.rb
index 3584e3c0..32e59216 100644
--- a/db/migrate/20170909151007_add_title_to_versions.rb
+++ b/db/migrate/20170909151007_add_title_to_versions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddTitleToVersions < ActiveRecord::Migration[5.1]
   def change
     add_column :versions, :title, :string
diff --git a/db/migrate/20170914154249_change_error_code_to_snake_case.rb b/db/migrate/20170914154249_change_error_code_to_snake_case.rb
index b06f93bf..f6c63ec3 100644
--- a/db/migrate/20170914154249_change_error_code_to_snake_case.rb
+++ b/db/migrate/20170914154249_change_error_code_to_snake_case.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ChangeErrorCodeToSnakeCase < ActiveRecord::Migration[5.1]
   def do_sql(*args)
     expression = ActiveRecord::Base.send :sanitize_sql, args
diff --git a/db/migrate/20171101214731_remove_page_uuid_site_index.rb b/db/migrate/20171101214731_remove_page_uuid_site_index.rb
index 687a01c8..912a25d4 100644
--- a/db/migrate/20171101214731_remove_page_uuid_site_index.rb
+++ b/db/migrate/20171101214731_remove_page_uuid_site_index.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemovePageUuidSiteIndex < ActiveRecord::Migration[5.1]
   def change
     add_index :pages, :site
diff --git a/db/migrate/20180128062846_create_maintainers.rb b/db/migrate/20180128062846_create_maintainers.rb
index ff0c7388..1d6bfded 100644
--- a/db/migrate/20180128062846_create_maintainers.rb
+++ b/db/migrate/20180128062846_create_maintainers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateMaintainers < ActiveRecord::Migration[5.1]
   def change
     enable_extension :citext
diff --git a/db/migrate/20180207031149_create_tags.rb b/db/migrate/20180207031149_create_tags.rb
index a3b1d643..6c4273eb 100644
--- a/db/migrate/20180207031149_create_tags.rb
+++ b/db/migrate/20180207031149_create_tags.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateTags < ActiveRecord::Migration[5.1]
   def change
     enable_extension :citext
diff --git a/db/migrate/20180207061655_copy_agency_and_site_fields_to_associated_models.rb b/db/migrate/20180207061655_copy_agency_and_site_fields_to_associated_models.rb
index 1d3c4974..6eaecaf2 100644
--- a/db/migrate/20180207061655_copy_agency_and_site_fields_to_associated_models.rb
+++ b/db/migrate/20180207061655_copy_agency_and_site_fields_to_associated_models.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CopyAgencyAndSiteFieldsToAssociatedModels < ActiveRecord::Migration[5.1]
   def up
     DataHelpers.iterate_each(Page.order(created_at: :asc)) do |page|
diff --git a/db/migrate/20180212043742_dedupe_pages_with_multiple_agencies_or_sites.rb b/db/migrate/20180212043742_dedupe_pages_with_multiple_agencies_or_sites.rb
index 291c07a1..c08b745e 100644
--- a/db/migrate/20180212043742_dedupe_pages_with_multiple_agencies_or_sites.rb
+++ b/db/migrate/20180212043742_dedupe_pages_with_multiple_agencies_or_sites.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DedupePagesWithMultipleAgenciesOrSites < ActiveRecord::Migration[5.1]
   # Find all pages sharing the same URL and de-duplicate them by copying the
   # maintainers, tags, and versions of all subsequent pages onto the one that
diff --git a/db/migrate/20180227021126_add_capture_url_to_version.rb b/db/migrate/20180227021126_add_capture_url_to_version.rb
index 6e9395d0..bce572c0 100644
--- a/db/migrate/20180227021126_add_capture_url_to_version.rb
+++ b/db/migrate/20180227021126_add_capture_url_to_version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddCaptureUrlToVersion < ActiveRecord::Migration[5.1]
   def change
     add_column :versions, :capture_url, :string
diff --git a/db/migrate/20180227024610_add_url_key_to_page.rb b/db/migrate/20180227024610_add_url_key_to_page.rb
index 6a92d6d6..73ca9f8d 100644
--- a/db/migrate/20180227024610_add_url_key_to_page.rb
+++ b/db/migrate/20180227024610_add_url_key_to_page.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddUrlKeyToPage < ActiveRecord::Migration[5.1]
   def change
     add_column :pages, :url_key, :string
diff --git a/db/migrate/20180227034314_dedupe_pages_with_matching_url_keys.rb b/db/migrate/20180227034314_dedupe_pages_with_matching_url_keys.rb
index 9883cb6a..a04eecdc 100644
--- a/db/migrate/20180227034314_dedupe_pages_with_matching_url_keys.rb
+++ b/db/migrate/20180227034314_dedupe_pages_with_matching_url_keys.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DedupePagesWithMatchingUrlKeys < ActiveRecord::Migration[5.1]
   # Find all pages sharing the same `url_key` and de-duplicate them by copying
   # the maintainers, tags, and versions of all subsequent pages onto the one
diff --git a/db/migrate/20180413051144_add_create_pages_to_imports.rb b/db/migrate/20180413051144_add_create_pages_to_imports.rb
index 66f1dada..e1316e64 100644
--- a/db/migrate/20180413051144_add_create_pages_to_imports.rb
+++ b/db/migrate/20180413051144_add_create_pages_to_imports.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddCreatePagesToImports < ActiveRecord::Migration[5.1]
   def change
     add_column :imports, :create_pages, :boolean, null: false, default: true
diff --git a/db/migrate/20180415063842_add_processing_warnings_to_imports.rb b/db/migrate/20180415063842_add_processing_warnings_to_imports.rb
index 00680890..b6beb3a9 100644
--- a/db/migrate/20180415063842_add_processing_warnings_to_imports.rb
+++ b/db/migrate/20180415063842_add_processing_warnings_to_imports.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddProcessingWarningsToImports < ActiveRecord::Migration[5.1]
   def change
     add_column :imports, :processing_warnings, :jsonb
diff --git a/db/migrate/20180415065623_add_different_to_versions.rb b/db/migrate/20180415065623_add_different_to_versions.rb
index 10906804..314a6d92 100644
--- a/db/migrate/20180415065623_add_different_to_versions.rb
+++ b/db/migrate/20180415065623_add_different_to_versions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddDifferentToVersions < ActiveRecord::Migration[5.1]
   def change
     add_column :versions, :different, :boolean, default: true
diff --git a/db/migrate/20180418061850_add_skip_unchanged_versions_to_imports.rb b/db/migrate/20180418061850_add_skip_unchanged_versions_to_imports.rb
index 2f03ee8b..5f80115a 100644
--- a/db/migrate/20180418061850_add_skip_unchanged_versions_to_imports.rb
+++ b/db/migrate/20180418061850_add_skip_unchanged_versions_to_imports.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddSkipUnchangedVersionsToImports < ActiveRecord::Migration[5.1]
   def change
     add_column :imports, :skip_unchanged_versions, :boolean, null: false, default: false
diff --git a/db/migrate/20181128194410_add_active_to_pages.rb b/db/migrate/20181128194410_add_active_to_pages.rb
index dcc412c8..188a1899 100644
--- a/db/migrate/20181128194410_add_active_to_pages.rb
+++ b/db/migrate/20181128194410_add_active_to_pages.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddActiveToPages < ActiveRecord::Migration[5.2]
   def change
     add_column :pages, :active, :boolean, default: true
diff --git a/db/migrate/20181204192154_add_status_to_versions_and_pages.rb b/db/migrate/20181204192154_add_status_to_versions_and_pages.rb
index 3b76ff0a..63466ab2 100644
--- a/db/migrate/20181204192154_add_status_to_versions_and_pages.rb
+++ b/db/migrate/20181204192154_add_status_to_versions_and_pages.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddStatusToVersionsAndPages < ActiveRecord::Migration[5.2]
   def change
     add_column :versions, :status, :integer, null: true
diff --git a/db/migrate/20190518154841_add_permissions_to_users.rb b/db/migrate/20190518154841_add_permissions_to_users.rb
index 52da6036..78a00fb3 100644
--- a/db/migrate/20190518154841_add_permissions_to_users.rb
+++ b/db/migrate/20190518154841_add_permissions_to_users.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddPermissionsToUsers < ActiveRecord::Migration[5.2]
   def up
     add_column :users, :permissions, :string, array: true, default: []
diff --git a/db/migrate/20190531175430_remove_admin_from_users.rb b/db/migrate/20190531175430_remove_admin_from_users.rb
index 70e3174a..c6698bb0 100644
--- a/db/migrate/20190531175430_remove_admin_from_users.rb
+++ b/db/migrate/20190531175430_remove_admin_from_users.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveAdminFromUsers < ActiveRecord::Migration[5.2]
   def up
     remove_column :users, :admin
diff --git a/db/migrate/20190617231901_add_common_indexes_to_versions.rb b/db/migrate/20190617231901_add_common_indexes_to_versions.rb
index 62b33fbe..4c2a9108 100644
--- a/db/migrate/20190617231901_add_common_indexes_to_versions.rb
+++ b/db/migrate/20190617231901_add_common_indexes_to_versions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddCommonIndexesToVersions < ActiveRecord::Migration[5.2]
   # Add indexes to support some common queries we do that should be faster.
   def change
diff --git a/db/migrate/20191101194241_add_foreign_key_constraint_to_active_storage_attachments_for_blob_id.active_storage.rb b/db/migrate/20191101194241_add_foreign_key_constraint_to_active_storage_attachments_for_blob_id.active_storage.rb
index ff5d72c7..7818547c 100644
--- a/db/migrate/20191101194241_add_foreign_key_constraint_to_active_storage_attachments_for_blob_id.active_storage.rb
+++ b/db/migrate/20191101194241_add_foreign_key_constraint_to_active_storage_attachments_for_blob_id.active_storage.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This migration comes from active_storage (originally 20180723000244)
 class AddForeignKeyConstraintToActiveStorageAttachmentsForBlobId < ActiveRecord::Migration[6.0]
   def up
diff --git a/db/migrate/20200216215324_add_length_and_media_type_to_versions.rb b/db/migrate/20200216215324_add_length_and_media_type_to_versions.rb
index 4a185298..759631a4 100644
--- a/db/migrate/20200216215324_add_length_and_media_type_to_versions.rb
+++ b/db/migrate/20200216215324_add_length_and_media_type_to_versions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddLengthAndMediaTypeToVersions < ActiveRecord::Migration[6.0]
   def change
     add_column :versions, :content_length, :integer, null: true
diff --git a/db/migrate/20201111182822_remove_site_and_agency_from_page.rb b/db/migrate/20201111182822_remove_site_and_agency_from_page.rb
index 9b726179..4d4bdbb1 100644
--- a/db/migrate/20201111182822_remove_site_and_agency_from_page.rb
+++ b/db/migrate/20201111182822_remove_site_and_agency_from_page.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveSiteAndAgencyFromPage < ActiveRecord::Migration[6.0]
   def change
     remove_column(:pages, :site, :string)
diff --git a/db/migrate/20201112194523_remove_media_type_parameters_from_version.rb b/db/migrate/20201112194523_remove_media_type_parameters_from_version.rb
index 711a4087..349aedad 100644
--- a/db/migrate/20201112194523_remove_media_type_parameters_from_version.rb
+++ b/db/migrate/20201112194523_remove_media_type_parameters_from_version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveMediaTypeParametersFromVersion < ActiveRecord::Migration[6.0]
   def change
     remove_column :versions, :media_type_parameters, :string, null: true
diff --git a/db/migrate/20201116224426_add_page_url_model.rb b/db/migrate/20201116224426_add_page_url_model.rb
index de9be965..6a138b08 100644
--- a/db/migrate/20201116224426_add_page_url_model.rb
+++ b/db/migrate/20201116224426_add_page_url_model.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddPageUrlModel < ActiveRecord::Migration[6.0]
   def change
     create_table :page_urls, id: false do |t|
diff --git a/db/migrate/20210101232014_add_service_name_to_active_storage_blobs.active_storage.rb b/db/migrate/20210101232014_add_service_name_to_active_storage_blobs.active_storage.rb
index 64e0ee43..0fa6bd93 100644
--- a/db/migrate/20210101232014_add_service_name_to_active_storage_blobs.active_storage.rb
+++ b/db/migrate/20210101232014_add_service_name_to_active_storage_blobs.active_storage.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This migration comes from active_storage (originally 20190112182829)
 class AddServiceNameToActiveStorageBlobs < ActiveRecord::Migration[6.0]
   def up
diff --git a/db/migrate/20210101232015_create_active_storage_variant_records.active_storage.rb b/db/migrate/20210101232015_create_active_storage_variant_records.active_storage.rb
index 67015fc4..23b07e35 100644
--- a/db/migrate/20210101232015_create_active_storage_variant_records.active_storage.rb
+++ b/db/migrate/20210101232015_create_active_storage_variant_records.active_storage.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This migration comes from active_storage (originally 20191206030411)
 class CreateActiveStorageVariantRecords < ActiveRecord::Migration[6.0]
   def change
diff --git a/db/migrate/20210605234433_rename_version_url_uri_hash_length_headers.rb b/db/migrate/20210605234433_rename_version_url_uri_hash_length_headers.rb
index db18d048..ae5f7dc7 100644
--- a/db/migrate/20210605234433_rename_version_url_uri_hash_length_headers.rb
+++ b/db/migrate/20210605234433_rename_version_url_uri_hash_length_headers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RenameVersionUrlUriHashLengthHeaders < ActiveRecord::Migration[6.1]
   def change
     change_table :versions do |t|
diff --git a/db/migrate/20220901211031_remove_not_null_on_active_storage_blobs_checksum.active_storage.rb b/db/migrate/20220901211031_remove_not_null_on_active_storage_blobs_checksum.active_storage.rb
index 93c8b85a..6f318221 100644
--- a/db/migrate/20220901211031_remove_not_null_on_active_storage_blobs_checksum.active_storage.rb
+++ b/db/migrate/20220901211031_remove_not_null_on_active_storage_blobs_checksum.active_storage.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This migration comes from active_storage (originally 20211119233751)
 class RemoveNotNullOnActiveStorageBlobsChecksum < ActiveRecord::Migration[6.0]
   def change
diff --git a/db/migrate/20230124182815_add_compound_time_uuid_indexes_on_versions.rb b/db/migrate/20230124182815_add_compound_time_uuid_indexes_on_versions.rb
index 88c0a61f..5cb07e17 100644
--- a/db/migrate/20230124182815_add_compound_time_uuid_indexes_on_versions.rb
+++ b/db/migrate/20230124182815_add_compound_time_uuid_indexes_on_versions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddCompoundTimeUuidIndexesOnVersions < ActiveRecord::Migration[7.0]
   disable_ddl_transaction!
 
diff --git a/db/migrate/20230124184531_remove_simple_time_indexes_on_versions.rb b/db/migrate/20230124184531_remove_simple_time_indexes_on_versions.rb
index 95e3afd1..b251221a 100644
--- a/db/migrate/20230124184531_remove_simple_time_indexes_on_versions.rb
+++ b/db/migrate/20230124184531_remove_simple_time_indexes_on_versions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveSimpleTimeIndexesOnVersions < ActiveRecord::Migration[7.0]
   def change
     # Drop indexes on Version time fields. These are now redundant since we
diff --git a/db/migrate/20230209200733_change_int_to_bigint_for_primary_keys.rb b/db/migrate/20230209200733_change_int_to_bigint_for_primary_keys.rb
index 7e4574a0..d09a233b 100644
--- a/db/migrate/20230209200733_change_int_to_bigint_for_primary_keys.rb
+++ b/db/migrate/20230209200733_change_int_to_bigint_for_primary_keys.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ChangeIntToBigintForPrimaryKeys < ActiveRecord::Migration[7.0]
   def change_serial_primary_key_type(table, key, key_type)
     change_column table, key, key_type
diff --git a/db/migrate/20250202234940_add_network_error_to_versions.rb b/db/migrate/20250202234940_add_network_error_to_versions.rb
index d6d85890..64b20c89 100644
--- a/db/migrate/20250202234940_add_network_error_to_versions.rb
+++ b/db/migrate/20250202234940_add_network_error_to_versions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddNetworkErrorToVersions < ActiveRecord::Migration[8.0]
   def change
     change_table :versions do |t|
diff --git a/db/seeds.rb b/db/seeds.rb
index 32703fee..658655c9 100644
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Seed the DB with an admin user and a few version records
 if Archiver.allowed_hosts.empty?
   puts <<~WARN
diff --git a/lib/api/api.rb b/lib/api/api.rb
index 64b05a2d..1dd03783 100644
--- a/lib/api/api.rb
+++ b/lib/api/api.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Api
   class ApiError < StandardError
   end
diff --git a/lib/archiver/archiver.rb b/lib/archiver/archiver.rb
index 9aace721..126b165a 100644
--- a/lib/archiver/archiver.rb
+++ b/lib/archiver/archiver.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'digest'
 require 'httparty'
 
diff --git a/lib/differ/differ.rb b/lib/differ/differ.rb
index 725c51db..2674ee3e 100644
--- a/lib/differ/differ.rb
+++ b/lib/differ/differ.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Differ
   # Register a differ instance to be used for a given diff type. If `type` is
   # nil, the differ will be treated as the constructor arguments for a differ
diff --git a/lib/differ/simple_diff.rb b/lib/differ/simple_diff.rb
index 51af8508..d456cb2a 100644
--- a/lib/differ/simple_diff.rb
+++ b/lib/differ/simple_diff.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Differ
   class SimpleDiff
     MAXIMUM_TRIES = 3
diff --git a/lib/file_storage/file_storage.rb b/lib/file_storage/file_storage.rb
index 1ce4e16a..ef395e27 100644
--- a/lib/file_storage/file_storage.rb
+++ b/lib/file_storage/file_storage.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative 'local_file'
 
 module FileStorage
diff --git a/lib/file_storage/local_file.rb b/lib/file_storage/local_file.rb
index afdd1f31..9efc725d 100644
--- a/lib/file_storage/local_file.rb
+++ b/lib/file_storage/local_file.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module FileStorage
   # Store and retrieve files from the local filesystem.
   class LocalFile
diff --git a/lib/file_storage/s3.rb b/lib/file_storage/s3.rb
index 31335b18..6ffbd5ee 100644
--- a/lib/file_storage/s3.rb
+++ b/lib/file_storage/s3.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'aws-sdk-s3'
 
 module FileStorage
diff --git a/lib/jwt_tools/jwt_auth_strategy.rb b/lib/jwt_tools/jwt_auth_strategy.rb
index c244a55c..cc8eef56 100644
--- a/lib/jwt_tools/jwt_auth_strategy.rb
+++ b/lib/jwt_tools/jwt_auth_strategy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module JwtTools
   class JwtAuthStrategy < Devise::Strategies::Base
     def valid?
diff --git a/lib/jwt_tools/jwt_coder.rb b/lib/jwt_tools/jwt_coder.rb
index c5e8ef5f..3147bb1f 100644
--- a/lib/jwt_tools/jwt_coder.rb
+++ b/lib/jwt_tools/jwt_coder.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module JwtTools
   module JwtCoder
     def self.private_key=(new_key)
diff --git a/lib/tasks/analyze_changes.rake b/lib/tasks/analyze_changes.rake
index f21dfeef..63fc047b 100644
--- a/lib/tasks/analyze_changes.rake
+++ b/lib/tasks/analyze_changes.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 desc 'Queue up automated analysis for versions added in a given timeframe.'
 task :analyze_changes, [:start_date, :end_date] => [:environment] do |_t, args|
   start_date = args.key?(:start_date) ? Time.parse(args[:start_date]) : nil
diff --git a/lib/tasks/cache_diffs.rake b/lib/tasks/cache_diffs.rake
index aa97208c..1157e804 100644
--- a/lib/tasks/cache_diffs.rake
+++ b/lib/tasks/cache_diffs.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 DEFAULT_DIFF_TYPES = [
   'html_token?include=all',
   'html_token?include=combined',
diff --git a/lib/tasks/copy_data.rake b/lib/tasks/copy_data.rake
index dc788240..8eaad3e2 100644
--- a/lib/tasks/copy_data.rake
+++ b/lib/tasks/copy_data.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 desc 'Copy pages from another web-monitoring-db instance.'
 task :copy_page, [:page_uuid, :include_changes, :url, :username, :password] => [:environment] do |_t, args|
   verbose = ENV.fetch('VERBOSE', nil)
diff --git a/lib/tasks/data/20180926_move_versionista_s3_data.rake b/lib/tasks/data/20180926_move_versionista_s3_data.rake
index 1d3135cf..e3201b1d 100644
--- a/lib/tasks/data/20180926_move_versionista_s3_data.rake
+++ b/lib/tasks/data/20180926_move_versionista_s3_data.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   # If the database is too big, use the date filters to break the work into
   # smaller, more time-constrained chunks.
diff --git a/lib/tasks/data/20181124_normalize_titles.rake b/lib/tasks/data/20181124_normalize_titles.rake
index 49d67bc8..d36b91cf 100644
--- a/lib/tasks/data/20181124_normalize_titles.rake
+++ b/lib/tasks/data/20181124_normalize_titles.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Clean up and normalize badly formatted Page and Version titles.'
   task :'20181124_normalize_titles', [] => [:environment] do |_t|
diff --git a/lib/tasks/data/20181204_set_version_status.rake b/lib/tasks/data/20181204_set_version_status.rake
index 40ef0dca..c06a0d00 100644
--- a/lib/tasks/data/20181204_set_version_status.rake
+++ b/lib/tasks/data/20181204_set_version_status.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Set the `status` field on all versions based on `source_metadata`.'
   task :'20181204_set_version_status', [] => [:environment] do |_t|
diff --git a/lib/tasks/data/20181205_update_version_different.rake b/lib/tasks/data/20181205_update_version_different.rake
index 1bee441c..3192ecfe 100644
--- a/lib/tasks/data/20181205_update_version_different.rake
+++ b/lib/tasks/data/20181205_update_version_different.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Set the `different` field on all versions.'
   task :'20181205_update_version_different', [] => [:environment] do |_t|
diff --git a/lib/tasks/data/20190112_add_page_domain_tags.rake b/lib/tasks/data/20190112_add_page_domain_tags.rake
index 8c20995c..df0e34a9 100644
--- a/lib/tasks/data/20190112_add_page_domain_tags.rake
+++ b/lib/tasks/data/20190112_add_page_domain_tags.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Set `domain:` and `2l-domain` tags on all pages.'
   task :'20190112_add_page_domain_tags', [] => [:environment] do |_t|
diff --git a/lib/tasks/data/20200218_add_version_length_media_type.rake b/lib/tasks/data/20200218_add_version_length_media_type.rake
index 6d6d7065..e3303048 100644
--- a/lib/tasks/data/20200218_add_version_length_media_type.rake
+++ b/lib/tasks/data/20200218_add_version_length_media_type.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Set `content_length`, and `media_type` on all versions.'
   task :'20200218_add_version_length_media_type', [:force, :start_date, :end_date] => [:environment] do |_t, args|
diff --git a/lib/tasks/data/20201116_add_page_urls.rake b/lib/tasks/data/20201116_add_page_urls.rake
index c7575eba..91091ff2 100644
--- a/lib/tasks/data/20201116_add_page_urls.rake
+++ b/lib/tasks/data/20201116_add_page_urls.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Add default PageUrls to all pages.'
   task :'20201116_add_page_urls', [] => [:environment] do
diff --git a/lib/tasks/data/20210605_fill_version_headers_from_source_metadata.rake b/lib/tasks/data/20210605_fill_version_headers_from_source_metadata.rake
index b619ef34..e7fb43af 100644
--- a/lib/tasks/data/20210605_fill_version_headers_from_source_metadata.rake
+++ b/lib/tasks/data/20210605_fill_version_headers_from_source_metadata.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Fill in `headers` on versions from `source_metadata.headers`.'
   task :'20210605_fill_version_headers_from_source_metadata', [:force, :start_date, :end_date] => [:environment] do |_t, args|
diff --git a/lib/tasks/data/20230119_remove_bad_versionista_titles.rake b/lib/tasks/data/20230119_remove_bad_versionista_titles.rake
index 277006e8..ecf36f73 100644
--- a/lib/tasks/data/20230119_remove_bad_versionista_titles.rake
+++ b/lib/tasks/data/20230119_remove_bad_versionista_titles.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Remove bad version titles from Versionista.'
   task :'20230119_remove_bad_versionista_titles', [] => [:environment] do |_t, _args|
diff --git a/lib/tasks/data/20230119_reset_page_titles.rake b/lib/tasks/data/20230119_reset_page_titles.rake
index 3fa21bcb..03c41c9f 100644
--- a/lib/tasks/data/20230119_reset_page_titles.rake
+++ b/lib/tasks/data/20230119_reset_page_titles.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Reset the titles for all pages based on new logic.'
   task :'20230119_reset_page_titles', [] => [:environment] do
diff --git a/lib/tasks/data/20250330_downcase_header_names.rake b/lib/tasks/data/20250330_downcase_header_names.rake
index f58e7562..639ada46 100644
--- a/lib/tasks/data/20250330_downcase_header_names.rake
+++ b/lib/tasks/data/20250330_downcase_header_names.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Ensure the names of headers in Version records are downcased.'
   task :'20250330_downcase_header_names', [:start_date, :end_date] => [:environment] do |_t, args|
diff --git a/lib/tasks/data/clean_media_types.rake b/lib/tasks/data/clean_media_types.rake
index aef27c00..68e34578 100644
--- a/lib/tasks/data/clean_media_types.rake
+++ b/lib/tasks/data/clean_media_types.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Clean up the media_type field on Versions, remap non-canonical to canonical types.'
   task :clean_media_types, [] => [:environment] do
diff --git a/lib/tasks/data/renormalize_urls.rake b/lib/tasks/data/renormalize_urls.rake
index 4e140619..96559347 100644
--- a/lib/tasks/data/renormalize_urls.rake
+++ b/lib/tasks/data/renormalize_urls.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Re-normalize the `url` field of Pages and PageUrls`.'
   task :renormalize_urls, [] => [:environment] do
diff --git a/lib/tasks/import_from_sheets.rake b/lib/tasks/import_from_sheets.rake
index 5d1b015a..fdc5629e 100644
--- a/lib/tasks/import_from_sheets.rake
+++ b/lib/tasks/import_from_sheets.rake
@@ -1,10 +1,12 @@
+# frozen_string_literal: true
+
 require 'google/apis/sheets_v4'
 require 'googleauth'
 require 'googleauth/stores/file_token_store'
 
-IMPORT_TYPE = 'rake_task_v1'.freeze
-OOB_URI = 'urn:ietf:wg:oauth:2.0:oob'.freeze
-APPLICATION_NAME = 'Web Monitoring DB Importer'.freeze
+IMPORT_TYPE = 'rake_task_v1'
+OOB_URI = 'urn:ietf:wg:oauth:2.0:oob'
+APPLICATION_NAME = 'Web Monitoring DB Importer'
 
 
 desc 'Create annotations from data in analysts’ Google sheets -- only sheet ID & user e-mail are required.'
diff --git a/lib/tasks/invitations.rake b/lib/tasks/invitations.rake
index 3d3adfed..fc576769 100644
--- a/lib/tasks/invitations.rake
+++ b/lib/tasks/invitations.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 desc 'Clean out expired invitations'
 task :remove_expired_invitations, [] => [:environment] do
   Invitation.expired.each do |invitation|
diff --git a/lib/tasks/merge_pages.rake b/lib/tasks/merge_pages.rake
index 6ed1a975..ab57ee77 100644
--- a/lib/tasks/merge_pages.rake
+++ b/lib/tasks/merge_pages.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 desc 'Merge multiple pages together. Pages will be merged *into* the first listed.'
 task :merge_pages, [] => :environment do |_t, args|
   DataHelpers.with_activerecord_log_level(:error) do
diff --git a/lib/tasks/update_page_statuses.rake b/lib/tasks/update_page_statuses.rake
index 7cdf539d..81ead041 100644
--- a/lib/tasks/update_page_statuses.rake
+++ b/lib/tasks/update_page_statuses.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 desc 'Update the `status` field on all pages. The first parameter optionally sets what pages to update: "recent" (default, pages updated recently enough to change status), "unknown" (only pages with unknown status), "all" (all pages)'
 task :update_page_statuses, [:where, :at_time] => [:environment] do |_t, args|
   where_options = ['recent', 'unknown', 'all']
diff --git a/test/application_system_test_case.rb b/test/application_system_test_case.rb
index 15e28785..871fa9fe 100644
--- a/test/application_system_test_case.rb
+++ b/test/application_system_test_case.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 Capybara.save_path = Rails.root.join('tmp')
diff --git a/test/controllers/admin/users_controller_test.rb b/test/controllers/admin/users_controller_test.rb
index 55f668a7..ce639084 100644
--- a/test/controllers/admin/users_controller_test.rb
+++ b/test/controllers/admin/users_controller_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class Admin::UsersControllerTest < ActionDispatch::IntegrationTest
diff --git a/test/controllers/admin_controller_test.rb b/test/controllers/admin_controller_test.rb
index a46d735a..dbe19bef 100644
--- a/test/controllers/admin_controller_test.rb
+++ b/test/controllers/admin_controller_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class AdminControllerTest < ActionDispatch::IntegrationTest
diff --git a/test/controllers/api/v0/annotations_controller_test.rb b/test/controllers/api/v0/annotations_controller_test.rb
index 042003fb..74fbd255 100644
--- a/test/controllers/api/v0/annotations_controller_test.rb
+++ b/test/controllers/api/v0/annotations_controller_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class Api::V0::AnnotationsControllerTest < ActionDispatch::IntegrationTest
diff --git a/test/controllers/api/v0/changes_controller_test.rb b/test/controllers/api/v0/changes_controller_test.rb
index d37e8e2a..c4d0186d 100644
--- a/test/controllers/api/v0/changes_controller_test.rb
+++ b/test/controllers/api/v0/changes_controller_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class Api::V0::ChangesControllerTest < ActionDispatch::IntegrationTest
diff --git a/test/controllers/api/v0/diff_controller_test.rb b/test/controllers/api/v0/diff_controller_test.rb
index eac8c200..3f7800bb 100644
--- a/test/controllers/api/v0/diff_controller_test.rb
+++ b/test/controllers/api/v0/diff_controller_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 require 'minitest/mock'
 
diff --git a/test/controllers/api/v0/imports_controller_test.rb b/test/controllers/api/v0/imports_controller_test.rb
index 4d0429c6..e25c0f5c 100644
--- a/test/controllers/api/v0/imports_controller_test.rb
+++ b/test/controllers/api/v0/imports_controller_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class Api::V0::ImportsControllerTest < ActionDispatch::IntegrationTest
diff --git a/test/controllers/api/v0/maintainers_controller_test.rb b/test/controllers/api/v0/maintainers_controller_test.rb
index 78d8c8e7..bd799b37 100644
--- a/test/controllers/api/v0/maintainers_controller_test.rb
+++ b/test/controllers/api/v0/maintainers_controller_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class Api::V0::MaintainersControllerTest < ActionDispatch::IntegrationTest
diff --git a/test/controllers/api/v0/pages_controller_test.rb b/test/controllers/api/v0/pages_controller_test.rb
index 7b5e3ea4..81764e75 100644
--- a/test/controllers/api/v0/pages_controller_test.rb
+++ b/test/controllers/api/v0/pages_controller_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class Api::V0::PagesControllerTest < ActionDispatch::IntegrationTest
diff --git a/test/controllers/api/v0/tags_controller_test.rb b/test/controllers/api/v0/tags_controller_test.rb
index 011db251..30947dae 100644
--- a/test/controllers/api/v0/tags_controller_test.rb
+++ b/test/controllers/api/v0/tags_controller_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class Api::V0::TagsControllerTest < ActionDispatch::IntegrationTest
diff --git a/test/controllers/api/v0/urls_controller_test.rb b/test/controllers/api/v0/urls_controller_test.rb
index 3b323065..a6a6c204 100644
--- a/test/controllers/api/v0/urls_controller_test.rb
+++ b/test/controllers/api/v0/urls_controller_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class Api::V0::UrlsControllerTest < ActionDispatch::IntegrationTest
diff --git a/test/controllers/api/v0/versions_controller_test.rb b/test/controllers/api/v0/versions_controller_test.rb
index 99a3a13b..b072956b 100644
--- a/test/controllers/api/v0/versions_controller_test.rb
+++ b/test/controllers/api/v0/versions_controller_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class Api::V0::VersionsControllerTest < ActionDispatch::IntegrationTest
diff --git a/test/controllers/healthcheck_controller_test.rb b/test/controllers/healthcheck_controller_test.rb
index 879fc6cf..97d8f13d 100644
--- a/test/controllers/healthcheck_controller_test.rb
+++ b/test/controllers/healthcheck_controller_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 require 'minitest/mock'
 
diff --git a/test/controllers/users/registrations_controller_test.rb b/test/controllers/users/registrations_controller_test.rb
index de6434c5..f9f26b48 100644
--- a/test/controllers/users/registrations_controller_test.rb
+++ b/test/controllers/users/registrations_controller_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class Users::RegistrationsControllerTest < ActionDispatch::IntegrationTest
diff --git a/test/controllers/users/sessions_controller_test.rb b/test/controllers/users/sessions_controller_test.rb
index 0597203f..2fa3181f 100644
--- a/test/controllers/users/sessions_controller_test.rb
+++ b/test/controllers/users/sessions_controller_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class Users::SessionsControllerTest < ActionDispatch::IntegrationTest
diff --git a/test/jobs/analyze_change_job_test.rb b/test/jobs/analyze_change_job_test.rb
index dcec7190..0d10d128 100644
--- a/test/jobs/analyze_change_job_test.rb
+++ b/test/jobs/analyze_change_job_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 require 'minitest/mock'
 
diff --git a/test/jobs/import_versions_job_test.rb b/test/jobs/import_versions_job_test.rb
index f74a98df..8a0c463e 100644
--- a/test/jobs/import_versions_job_test.rb
+++ b/test/jobs/import_versions_job_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ImportVersionsJobTest < ActiveJob::TestCase
diff --git a/test/lib/archiver/archiver_test.rb b/test/lib/archiver/archiver_test.rb
index 7c395fc2..05b0ed18 100644
--- a/test/lib/archiver/archiver_test.rb
+++ b/test/lib/archiver/archiver_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class Archiver::ArchiverTest < ActiveSupport::TestCase
diff --git a/test/lib/differ/differ_test.rb b/test/lib/differ/differ_test.rb
index e947f682..4ff69657 100644
--- a/test/lib/differ/differ_test.rb
+++ b/test/lib/differ/differ_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class Differ::DifferTest < ActiveSupport::TestCase
diff --git a/test/lib/differ/simple_diff_test.rb b/test/lib/differ/simple_diff_test.rb
index e6b18b24..8a8f75d9 100644
--- a/test/lib/differ/simple_diff_test.rb
+++ b/test/lib/differ/simple_diff_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class Differ::SimpleDiffTest < ActiveSupport::TestCase
diff --git a/test/lib/file_storage/local_file_test.rb b/test/lib/file_storage/local_file_test.rb
index 87cf2535..21092930 100644
--- a/test/lib/file_storage/local_file_test.rb
+++ b/test/lib/file_storage/local_file_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class FileStorage::LocalFileTest < ActiveSupport::TestCase
diff --git a/test/lib/file_storage/s3_test.rb b/test/lib/file_storage/s3_test.rb
index 0a185e89..1eeb151e 100644
--- a/test/lib/file_storage/s3_test.rb
+++ b/test/lib/file_storage/s3_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class FileStorage::S3Test < ActiveSupport::TestCase
diff --git a/test/lib/good_job_test.rb b/test/lib/good_job_test.rb
index e1e19865..5d748db7 100644
--- a/test/lib/good_job_test.rb
+++ b/test/lib/good_job_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class GoodJobTest < ActiveSupport::TestCase
diff --git a/test/lib/numeric_interval_test.rb b/test/lib/numeric_interval_test.rb
index 22d817d1..ab8e25f7 100644
--- a/test/lib/numeric_interval_test.rb
+++ b/test/lib/numeric_interval_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class NumericIntervalTest < ActiveSupport::TestCase
diff --git a/test/lib/surt/surt_test.rb b/test/lib/surt/surt_test.rb
index 12a33e19..b7f768e9 100644
--- a/test/lib/surt/surt_test.rb
+++ b/test/lib/surt/surt_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class SurtTest < ActiveSupport::TestCase
diff --git a/test/mailers/invitation_mailer_test.rb b/test/mailers/invitation_mailer_test.rb
index 86d3ea47..e0c4fafe 100644
--- a/test/mailers/invitation_mailer_test.rb
+++ b/test/mailers/invitation_mailer_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class InvitationMailerTest < ActionMailer::TestCase
diff --git a/test/models/annotation_test.rb b/test/models/annotation_test.rb
index 956f8aec..ef996c29 100644
--- a/test/models/annotation_test.rb
+++ b/test/models/annotation_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class AnnotationTest < ActiveSupport::TestCase
diff --git a/test/models/application_record_test.rb b/test/models/application_record_test.rb
index 487a475b..fb7f4b4d 100644
--- a/test/models/application_record_test.rb
+++ b/test/models/application_record_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ApplicationRecordTest < ActiveSupport::TestCase
diff --git a/test/models/change_test.rb b/test/models/change_test.rb
index 2f536d83..1be77831 100644
--- a/test/models/change_test.rb
+++ b/test/models/change_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ChangeTest < ActiveSupport::TestCase
diff --git a/test/models/import_test.rb b/test/models/import_test.rb
index 57bba88c..4485ab61 100644
--- a/test/models/import_test.rb
+++ b/test/models/import_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ImportTest < ActiveSupport::TestCase
diff --git a/test/models/invitation_test.rb b/test/models/invitation_test.rb
index f90a6ab2..97004c2e 100644
--- a/test/models/invitation_test.rb
+++ b/test/models/invitation_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class InvitationTest < ActiveSupport::TestCase
diff --git a/test/models/page_test.rb b/test/models/page_test.rb
index 45005157..ad25dfce 100644
--- a/test/models/page_test.rb
+++ b/test/models/page_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class PageTest < ActiveSupport::TestCase
diff --git a/test/models/page_url_test.rb b/test/models/page_url_test.rb
index 1fbbb17f..4ae9c384 100644
--- a/test/models/page_url_test.rb
+++ b/test/models/page_url_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class PageUrlTest < ActiveSupport::TestCase
diff --git a/test/models/user_test.rb b/test/models/user_test.rb
index 10049b20..6a580f3b 100644
--- a/test/models/user_test.rb
+++ b/test/models/user_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class UserTest < ActiveSupport::TestCase
diff --git a/test/models/version_test.rb b/test/models/version_test.rb
index 6567e260..59de13a6 100644
--- a/test/models/version_test.rb
+++ b/test/models/version_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class VersionTest < ActiveSupport::TestCase
diff --git a/test/system/users_test.rb b/test/system/users_test.rb
index a594980d..58824578 100644
--- a/test/system/users_test.rb
+++ b/test/system/users_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'application_system_test_case'
 
 class UsersTest < ApplicationSystemTestCase
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 60a478cf..2f2967d4 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 ENV['RAILS_ENV'] ||= 'test'
 require File.expand_path('../config/environment', __dir__)
 require 'rails/test_help'