Introduce ApplicationSettingImplementation yay

So the fake can enjoy it, too. We don't use `prepend`
because that'll require we change `allow_any_instance_of` to
`expect_next_instance_of`, but that's not very easy to do.
We can do that later.

app/models/application_setting.rb

@@ -7,21 +7,11 @@ class ApplicationSetting < ActiveRecord::Base
   include IgnorableColumn
   include ChronicDurationAttribute
 
+  include ApplicationSettingImplementation
+
   add_authentication_token_field :runners_registration_token, encrypted: -> { Feature.enabled?(:application_settings_tokens_optional_encryption) ? :optional : :required }
   add_authentication_token_field :health_check_access_token
 
-  DOMAIN_LIST_SEPARATOR = %r{\s*[,;]\s*     # comma or semicolon, optionally surrounded by whitespace
-                            |               # or
-                            \s              # any whitespace character
-                            |               # or
-                            [\r\n]          # any number of newline characters
-                          }x
-
-  # Setting a key restriction to `-1` means that all keys of this type are
-  # forbidden.
-  FORBIDDEN_KEY_VALUE = KeyRestrictionValidator::FORBIDDEN
-  SUPPORTED_KEY_TYPES = %i[rsa dsa ecdsa ed25519].freeze
-
   serialize :restricted_visibility_levels # rubocop:disable Cop/ActiveRecordSerialize
   serialize :import_sources # rubocop:disable Cop/ActiveRecordSerialize
   serialize :disabled_oauth_sign_in_sources, Array # rubocop:disable Cop/ActiveRecordSerialize
@@ -42,8 +32,6 @@ class ApplicationSetting < ActiveRecord::Base
   cache_markdown_field :shared_runners_text, pipeline: :plain_markdown
   cache_markdown_field :after_sign_up_text
 
-  attr_accessor :domain_whitelist_raw, :domain_blacklist_raw
-
   default_value_for :id, 1
 
   chronic_duration_attr_writer :archive_builds_in_human_readable, :archive_builds_in_seconds
@@ -231,266 +219,4 @@ class ApplicationSetting < ActiveRecord::Base
     reset_memoized_terms
   end
   after_commit :expire_performance_bar_allowed_user_ids_cache, if: -> { previous_changes.key?('performance_bar_allowed_group_id') }
-
-  def self.defaults
-    {
-      after_sign_up_text: nil,
-      akismet_enabled: false,
-      allow_local_requests_from_hooks_and_services: false,
-      authorized_keys_enabled: true, # TODO default to false if the instance is configured to use AuthorizedKeysCommand
-      container_registry_token_expire_delay: 5,
-      default_artifacts_expire_in: '30 days',
-      default_branch_protection: Settings.gitlab['default_branch_protection'],
-      default_group_visibility: Settings.gitlab.default_projects_features['visibility_level'],
-      default_project_visibility: Settings.gitlab.default_projects_features['visibility_level'],
-      default_projects_limit: Settings.gitlab['default_projects_limit'],
-      default_snippet_visibility: Settings.gitlab.default_projects_features['visibility_level'],
-      disabled_oauth_sign_in_sources: [],
-      domain_whitelist: Settings.gitlab['domain_whitelist'],
-      dsa_key_restriction: 0,
-      ecdsa_key_restriction: 0,
-      ed25519_key_restriction: 0,
-      first_day_of_week: 0,
-      gitaly_timeout_default: 55,
-      gitaly_timeout_fast: 10,
-      gitaly_timeout_medium: 30,
-      gravatar_enabled: Settings.gravatar['enabled'],
-      help_page_hide_commercial_content: false,
-      help_page_text: nil,
-      hide_third_party_offers: false,
-      housekeeping_bitmaps_enabled: true,
-      housekeeping_enabled: true,
-      housekeeping_full_repack_period: 50,
-      housekeeping_gc_period: 200,
-      housekeeping_incremental_repack_period: 10,
-      import_sources: Settings.gitlab['import_sources'],
-      max_artifacts_size: Settings.artifacts['max_size'],
-      max_attachment_size: Settings.gitlab['max_attachment_size'],
-      mirror_available: true,
-      password_authentication_enabled_for_git: true,
-      password_authentication_enabled_for_web: Settings.gitlab['signin_enabled'],
-      performance_bar_allowed_group_id: nil,
-      rsa_key_restriction: 0,
-      plantuml_enabled: false,
-      plantuml_url: nil,
-      polling_interval_multiplier: 1,
-      project_export_enabled: true,
-      recaptcha_enabled: false,
-      repository_checks_enabled: true,
-      repository_storages: ['default'],
-      require_two_factor_authentication: false,
-      restricted_visibility_levels: Settings.gitlab['restricted_visibility_levels'],
-      session_expire_delay: Settings.gitlab['session_expire_delay'],
-      send_user_confirmation_email: false,
-      shared_runners_enabled: Settings.gitlab_ci['shared_runners_enabled'],
-      shared_runners_text: nil,
-      sign_in_text: nil,
-      signup_enabled: Settings.gitlab['signup_enabled'],
-      terminal_max_session_time: 0,
-      throttle_authenticated_api_enabled: false,
-      throttle_authenticated_api_period_in_seconds: 3600,
-      throttle_authenticated_api_requests_per_period: 7200,
-      throttle_authenticated_web_enabled: false,
-      throttle_authenticated_web_period_in_seconds: 3600,
-      throttle_authenticated_web_requests_per_period: 7200,
-      throttle_unauthenticated_enabled: false,
-      throttle_unauthenticated_period_in_seconds: 3600,
-      throttle_unauthenticated_requests_per_period: 3600,
-      two_factor_grace_period: 48,
-      unique_ips_limit_enabled: false,
-      unique_ips_limit_per_user: 10,
-      unique_ips_limit_time_window: 3600,
-      usage_ping_enabled: Settings.gitlab['usage_ping_enabled'],
-      instance_statistics_visibility_private: false,
-      user_default_external: false,
-      user_default_internal_regex: nil,
-      user_show_add_ssh_key_message: true,
-      usage_stats_set_by_user_id: nil,
-      diff_max_patch_bytes: Gitlab::Git::Diff::DEFAULT_MAX_PATCH_BYTES,
-      commit_email_hostname: default_commit_email_hostname,
-      protected_ci_variables: false,
-      local_markdown_version: 0
-    }
-  end
-
-  def self.default_commit_email_hostname
-    "users.noreply.#{Gitlab.config.gitlab.host}"
-  end
-
-  def self.create_from_defaults
-    build_from_defaults.tap(&:save)
-  end
-
-  def self.human_attribute_name(attr, _options = {})
-    if attr == :default_artifacts_expire_in
-      'Default artifacts expiration'
-    else
-      super
-    end
-  end
-
-  def home_page_url_column_exists?
-    ::Gitlab::Database.cached_column_exists?(:application_settings, :home_page_url)
-  end
-
-  def help_page_support_url_column_exists?
-    ::Gitlab::Database.cached_column_exists?(:application_settings, :help_page_support_url)
-  end
-
-  def disabled_oauth_sign_in_sources=(sources)
-    sources = (sources || []).map(&:to_s) & Devise.omniauth_providers.map(&:to_s)
-    super(sources)
-  end
-
-  def domain_whitelist_raw
-    self.domain_whitelist&.join("\n")
-  end
-
-  def domain_blacklist_raw
-    self.domain_blacklist&.join("\n")
-  end
-
-  def domain_whitelist_raw=(values)
-    self.domain_whitelist = []
-    self.domain_whitelist = values.split(DOMAIN_LIST_SEPARATOR)
-    self.domain_whitelist.reject! { |d| d.empty? }
-    self.domain_whitelist
-  end
-
-  def domain_blacklist_raw=(values)
-    self.domain_blacklist = []
-    self.domain_blacklist = values.split(DOMAIN_LIST_SEPARATOR)
-    self.domain_blacklist.reject! { |d| d.empty? }
-    self.domain_blacklist
-  end
-
-  def domain_blacklist_file=(file)
-    self.domain_blacklist_raw = file.read
-  end
-
-  def repository_storages
-    Array(read_attribute(:repository_storages))
-  end
-
-  def commit_email_hostname
-    super.presence || self.class.default_commit_email_hostname
-  end
-
-  def default_project_visibility=(level)
-    super(Gitlab::VisibilityLevel.level_value(level))
-  end
-
-  def default_snippet_visibility=(level)
-    super(Gitlab::VisibilityLevel.level_value(level))
-  end
-
-  def default_group_visibility=(level)
-    super(Gitlab::VisibilityLevel.level_value(level))
-  end
-
-  def restricted_visibility_levels=(levels)
-    super(levels&.map { |level| Gitlab::VisibilityLevel.level_value(level) })
-  end
-
-  def strip_sentry_values
-    sentry_dsn.strip! if sentry_dsn.present?
-    clientside_sentry_dsn.strip! if clientside_sentry_dsn.present?
-  end
-
-  def performance_bar_allowed_group
-    Group.find_by_id(performance_bar_allowed_group_id)
-  end
-
-  # Return true if the Performance Bar is enabled for a given group
-  def performance_bar_enabled
-    performance_bar_allowed_group_id.present?
-  end
-
-  # Choose one of the available repository storage options. Currently all have
-  # equal weighting.
-  def pick_repository_storage
-    repository_storages.sample
-  end
-
-  def runners_registration_token
-    ensure_runners_registration_token!
-  end
-
-  def health_check_access_token
-    ensure_health_check_access_token!
-  end
-
-  def usage_ping_can_be_configured?
-    Settings.gitlab.usage_ping_enabled
-  end
-
-  def usage_ping_enabled
-    usage_ping_can_be_configured? && super
-  end
-
-  def allowed_key_types
-    SUPPORTED_KEY_TYPES.select do |type|
-      key_restriction_for(type) != FORBIDDEN_KEY_VALUE
-    end
-  end
-
-  def key_restriction_for(type)
-    attr_name = "#{type}_key_restriction"
-
-    has_attribute?(attr_name) ? public_send(attr_name) : FORBIDDEN_KEY_VALUE # rubocop:disable GitlabSecurity/PublicSend
-  end
-
-  def allow_signup?
-    signup_enabled? && password_authentication_enabled_for_web?
-  end
-
-  def password_authentication_enabled?
-    password_authentication_enabled_for_web? || password_authentication_enabled_for_git?
-  end
-
-  def user_default_internal_regex_enabled?
-    user_default_external? && user_default_internal_regex.present?
-  end
-
-  def user_default_internal_regex_instance
-    Regexp.new(user_default_internal_regex, Regexp::IGNORECASE)
-  end
-
-  delegate :terms, to: :latest_terms, allow_nil: true
-  def latest_terms
-    @latest_terms ||= Term.latest
-  end
-
-  def reset_memoized_terms
-    @latest_terms = nil
-    latest_terms
-  end
-
-  def archive_builds_older_than
-    archive_builds_in_seconds.seconds.ago if archive_builds_in_seconds
-  end
-
-  private
-
-  def ensure_uuid!
-    return if uuid?
-
-    self.uuid = SecureRandom.uuid
-  end
-
-  def check_repository_storages
-    invalid = repository_storages - Gitlab.config.repositories.storages.keys
-    errors.add(:repository_storages, "can't include: #{invalid.join(", ")}") unless
-      invalid.empty?
-  end
-
-  def terms_exist
-    return unless enforce_terms?
-
-    errors.add(:terms, "You need to set terms to be enforced") unless terms.present?
-  end
-
-  def expire_performance_bar_allowed_user_ids_cache
-    Gitlab::PerformanceBar.expire_allowed_user_ids_cache
-  end
 end

app/models/application_setting_implementation.rb

@@ -0,0 +1,281 @@
+# frozen_string_literal: true
+
+module ApplicationSettingImplementation
+  extend ActiveSupport::Concern
+
+  DOMAIN_LIST_SEPARATOR = %r{\s*[,;]\s*     # comma or semicolon, optionally surrounded by whitespace
+                            |               # or
+                            \s              # any whitespace character
+                            |               # or
+                            [\r\n]          # any number of newline characters
+                          }x
+
+  # Setting a key restriction to `-1` means that all keys of this type are
+  # forbidden.
+  FORBIDDEN_KEY_VALUE = KeyRestrictionValidator::FORBIDDEN
+  SUPPORTED_KEY_TYPES = %i[rsa dsa ecdsa ed25519].freeze
+
+  class_methods do
+    def defaults
+      {
+        after_sign_up_text: nil,
+        akismet_enabled: false,
+        allow_local_requests_from_hooks_and_services: false,
+        authorized_keys_enabled: true, # TODO default to false if the instance is configured to use AuthorizedKeysCommand
+        container_registry_token_expire_delay: 5,
+        default_artifacts_expire_in: '30 days',
+        default_branch_protection: Settings.gitlab['default_branch_protection'],
+        default_group_visibility: Settings.gitlab.default_projects_features['visibility_level'],
+        default_project_visibility: Settings.gitlab.default_projects_features['visibility_level'],
+        default_projects_limit: Settings.gitlab['default_projects_limit'],
+        default_snippet_visibility: Settings.gitlab.default_projects_features['visibility_level'],
+        disabled_oauth_sign_in_sources: [],
+        domain_whitelist: Settings.gitlab['domain_whitelist'],
+        dsa_key_restriction: 0,
+        ecdsa_key_restriction: 0,
+        ed25519_key_restriction: 0,
+        first_day_of_week: 0,
+        gitaly_timeout_default: 55,
+        gitaly_timeout_fast: 10,
+        gitaly_timeout_medium: 30,
+        gravatar_enabled: Settings.gravatar['enabled'],
+        help_page_hide_commercial_content: false,
+        help_page_text: nil,
+        hide_third_party_offers: false,
+        housekeeping_bitmaps_enabled: true,
+        housekeeping_enabled: true,
+        housekeeping_full_repack_period: 50,
+        housekeeping_gc_period: 200,
+        housekeeping_incremental_repack_period: 10,
+        import_sources: Settings.gitlab['import_sources'],
+        max_artifacts_size: Settings.artifacts['max_size'],
+        max_attachment_size: Settings.gitlab['max_attachment_size'],
+        mirror_available: true,
+        password_authentication_enabled_for_git: true,
+        password_authentication_enabled_for_web: Settings.gitlab['signin_enabled'],
+        performance_bar_allowed_group_id: nil,
+        rsa_key_restriction: 0,
+        plantuml_enabled: false,
+        plantuml_url: nil,
+        polling_interval_multiplier: 1,
+        project_export_enabled: true,
+        recaptcha_enabled: false,
+        repository_checks_enabled: true,
+        repository_storages: ['default'],
+        require_two_factor_authentication: false,
+        restricted_visibility_levels: Settings.gitlab['restricted_visibility_levels'],
+        session_expire_delay: Settings.gitlab['session_expire_delay'],
+        send_user_confirmation_email: false,
+        shared_runners_enabled: Settings.gitlab_ci['shared_runners_enabled'],
+        shared_runners_text: nil,
+        sign_in_text: nil,
+        signup_enabled: Settings.gitlab['signup_enabled'],
+        terminal_max_session_time: 0,
+        throttle_authenticated_api_enabled: false,
+        throttle_authenticated_api_period_in_seconds: 3600,
+        throttle_authenticated_api_requests_per_period: 7200,
+        throttle_authenticated_web_enabled: false,
+        throttle_authenticated_web_period_in_seconds: 3600,
+        throttle_authenticated_web_requests_per_period: 7200,
+        throttle_unauthenticated_enabled: false,
+        throttle_unauthenticated_period_in_seconds: 3600,
+        throttle_unauthenticated_requests_per_period: 3600,
+        two_factor_grace_period: 48,
+        unique_ips_limit_enabled: false,
+        unique_ips_limit_per_user: 10,
+        unique_ips_limit_time_window: 3600,
+        usage_ping_enabled: Settings.gitlab['usage_ping_enabled'],
+        instance_statistics_visibility_private: false,
+        user_default_external: false,
+        user_default_internal_regex: nil,
+        user_show_add_ssh_key_message: true,
+        usage_stats_set_by_user_id: nil,
+        diff_max_patch_bytes: Gitlab::Git::Diff::DEFAULT_MAX_PATCH_BYTES,
+        commit_email_hostname: default_commit_email_hostname,
+        protected_ci_variables: false,
+        local_markdown_version: 0
+      }
+    end
+
+    def default_commit_email_hostname
+      "users.noreply.#{Gitlab.config.gitlab.host}"
+    end
+
+    def create_from_defaults
+      build_from_defaults.tap(&:save)
+    end
+
+    def human_attribute_name(attr, _options = {})
+      if attr == :default_artifacts_expire_in
+        'Default artifacts expiration'
+      else
+        super
+      end
+    end
+  end
+
+  def home_page_url_column_exists?
+    ::Gitlab::Database.cached_column_exists?(:application_settings, :home_page_url)
+  end
+
+  def help_page_support_url_column_exists?
+    ::Gitlab::Database.cached_column_exists?(:application_settings, :help_page_support_url)
+  end
+
+  def disabled_oauth_sign_in_sources=(sources)
+    sources = (sources || []).map(&:to_s) & Devise.omniauth_providers.map(&:to_s)
+    super(sources)
+  end
+
+  def domain_whitelist_raw
+    self.domain_whitelist&.join("\n")
+  end
+
+  def domain_blacklist_raw
+    self.domain_blacklist&.join("\n")
+  end
+
+  def domain_whitelist_raw=(values)
+    self.domain_whitelist = []
+    self.domain_whitelist = values.split(DOMAIN_LIST_SEPARATOR)
+    self.domain_whitelist.reject! { |d| d.empty? }
+    self.domain_whitelist
+  end
+
+  def domain_blacklist_raw=(values)
+    self.domain_blacklist = []
+    self.domain_blacklist = values.split(DOMAIN_LIST_SEPARATOR)
+    self.domain_blacklist.reject! { |d| d.empty? }
+    self.domain_blacklist
+  end
+
+  def domain_blacklist_file=(file)
+    self.domain_blacklist_raw = file.read
+  end
+
+  def repository_storages
+    Array(read_attribute(:repository_storages))
+  end
+
+  def commit_email_hostname
+    super.presence || self.class.default_commit_email_hostname
+  end
+
+  def default_project_visibility=(level)
+    super(Gitlab::VisibilityLevel.level_value(level))
+  end
+
+  def default_snippet_visibility=(level)
+    super(Gitlab::VisibilityLevel.level_value(level))
+  end
+
+  def default_group_visibility=(level)
+    super(Gitlab::VisibilityLevel.level_value(level))
+  end
+
+  def restricted_visibility_levels=(levels)
+    super(levels&.map { |level| Gitlab::VisibilityLevel.level_value(level) })
+  end
+
+  def strip_sentry_values
+    sentry_dsn.strip! if sentry_dsn.present?
+    clientside_sentry_dsn.strip! if clientside_sentry_dsn.present?
+  end
+
+  def performance_bar_allowed_group
+    Group.find_by_id(performance_bar_allowed_group_id)
+  end
+
+  # Return true if the Performance Bar is enabled for a given group
+  def performance_bar_enabled
+    performance_bar_allowed_group_id.present?
+  end
+
+  # Choose one of the available repository storage options. Currently all have
+  # equal weighting.
+  def pick_repository_storage
+    repository_storages.sample
+  end
+
+  def runners_registration_token
+    ensure_runners_registration_token!
+  end
+
+  def health_check_access_token
+    ensure_health_check_access_token!
+  end
+
+  def usage_ping_can_be_configured?
+    Settings.gitlab.usage_ping_enabled
+  end
+
+  def usage_ping_enabled
+    usage_ping_can_be_configured? && super
+  end
+
+  def allowed_key_types
+    SUPPORTED_KEY_TYPES.select do |type|
+      key_restriction_for(type) != FORBIDDEN_KEY_VALUE
+    end
+  end
+
+  def key_restriction_for(type)
+    attr_name = "#{type}_key_restriction"
+
+    has_attribute?(attr_name) ? public_send(attr_name) : FORBIDDEN_KEY_VALUE # rubocop:disable GitlabSecurity/PublicSend
+  end
+
+  def allow_signup?
+    signup_enabled? && password_authentication_enabled_for_web?
+  end
+
+  def password_authentication_enabled?
+    password_authentication_enabled_for_web? || password_authentication_enabled_for_git?
+  end
+
+  def user_default_internal_regex_enabled?
+    user_default_external? && user_default_internal_regex.present?
+  end
+
+  def user_default_internal_regex_instance
+    Regexp.new(user_default_internal_regex, Regexp::IGNORECASE)
+  end
+
+  delegate :terms, to: :latest_terms, allow_nil: true
+  def latest_terms
+    @latest_terms ||= ApplicationSetting::Term.latest
+  end
+
+  def reset_memoized_terms
+    @latest_terms = nil # rubocop:disable Gitlab/ModuleWithInstanceVariables
+    latest_terms
+  end
+
+  def archive_builds_older_than
+    archive_builds_in_seconds.seconds.ago if archive_builds_in_seconds
+  end
+
+  private
+
+  def ensure_uuid!
+    return if uuid?
+
+    self.uuid = SecureRandom.uuid
+  end
+
+  def check_repository_storages
+    invalid = repository_storages - Gitlab.config.repositories.storages.keys
+    errors.add(:repository_storages, "can't include: #{invalid.join(", ")}") unless
+      invalid.empty?
+  end
+
+  def terms_exist
+    return unless enforce_terms?
+
+    errors.add(:terms, "You need to set terms to be enforced") unless terms.present?
+  end
+
+  def expire_performance_bar_allowed_user_ids_cache
+    Gitlab::PerformanceBar.expire_allowed_user_ids_cache
+  end
+end

lib/gitlab/fake_application_settings.rb

@@ -7,6 +7,8 @@
 # column type without parsing db/schema.rb.
 module Gitlab
   class FakeApplicationSettings < OpenStruct
+    include ApplicationSettingImplementation
+
     # Mimic ActiveRecord predicate methods for boolean values
     def self.define_predicate_methods(options)
       options.each do |key, value|
@@ -26,20 +28,7 @@ module Gitlab
       FakeApplicationSettings.define_predicate_methods(options)
     end
 
-    def key_restriction_for(type)
+    alias_method :read_attribute, :[]
-      0
+    alias_method :has_attribute?, :[]
-    end
-
-    def allowed_key_types
-      ApplicationSetting::SUPPORTED_KEY_TYPES
-    end
-
-    def pick_repository_storage
-      repository_storages.sample
-    end
-
-    def commit_email_hostname
-      super.presence || ApplicationSetting.default_commit_email_hostname
-    end
   end
 end

spec/controllers/registrations_controller_spec.rb

@@ -15,7 +15,7 @@ describe RegistrationsController do
 
       context 'when send_user_confirmation_email is false' do
         it 'signs the user in' do
-          allow_any_instance_of(ApplicationSetting).to receive(:send_user_confirmation_email).and_return(false)
+          stub_application_setting(send_user_confirmation_email: false)
 
           expect { post(:create, params: user_params) }.not_to change { ActionMailer::Base.deliveries.size }
           expect(subject.current_user).not_to be_nil
@@ -24,7 +24,7 @@ describe RegistrationsController do
 
       context 'when send_user_confirmation_email is true' do
         it 'does not authenticate user and sends confirmation email' do
-          allow_any_instance_of(ApplicationSetting).to receive(:send_user_confirmation_email).and_return(true)
+          stub_application_setting(send_user_confirmation_email: true)
 
           post(:create, params: user_params)
 
@@ -35,7 +35,7 @@ describe RegistrationsController do
 
       context 'when signup_enabled? is false' do
         it 'redirects to sign_in' do
-          allow_any_instance_of(ApplicationSetting).to receive(:signup_enabled?).and_return(false)
+          stub_application_setting(signup_enabled: false)
 
           expect { post(:create, params: user_params) }.not_to change(User, :count)
           expect(response).to redirect_to(new_user_session_path)