Add config.action_text.sanitizer_vendor

Rails 7.1 defaults to Rails::HTML::Sanitizer.best_supported_vendor,
earlier configs will use Rails::HTML4::Sanitizer.

Related to #48523 / 55bca6b8.

actiontext/CHANGELOG.md

@@ -1,3 +1,16 @@
+*   Use `Rails::HTML5::SafeListSanitizer` by default in the Rails 7.1 configuration if it is
+    supported.
+
+    Action Text's sanitizer can be configured by setting
+    `config.action_text.sanitizer_vendor`. Supported values are `Rails::HTML4::Sanitizer` or
+    `Rails::HTML5::Sanitizer`.
+
+    The Rails 7.1 configuration will set this to `Rails::HTML5::Sanitizer` when it is supported, and
+    fall back to `Rails::HTML4::Sanitizer`. Previous configurations default to
+    `Rails::HTML4::Sanitizer`.
+
+    *Mike Dalessio*
+
 *   Attachables now can override default attachment missing template.
 
     When rendering Action Text attachments where the underlying attachable model has

actiontext/app/helpers/action_text/content_helper.rb

@@ -4,7 +4,7 @@
 
 module ActionText
   module ContentHelper
-    mattr_accessor(:sanitizer) { Rails::Html::Sanitizer.best_supported_vendor.safe_list_sanitizer.new }
+    mattr_accessor(:sanitizer, default: Rails::HTML4::Sanitizer.safe_list_sanitizer.new)
     mattr_accessor(:allowed_tags) { sanitizer.class.allowed_tags + [ ActionText::Attachment.tag_name, "figure", "figcaption" ] }
     mattr_accessor(:allowed_attributes) { sanitizer.class.allowed_attributes + ActionText::Attachment::ATTRIBUTES }
     mattr_accessor(:scrubber)

actiontext/lib/action_text/engine.rb

@@ -82,5 +82,11 @@ def to_trix_content_attachment_partial_path
     initializer "action_text.configure" do |app|
       ActionText::Attachment.tag_name = app.config.action_text.attachment_tag_name
     end
+
+    initializer "action_text.sanitizer_vendor" do |app|
+      if klass = app.config.action_text.delete(:sanitizer_vendor)
+        ActionText::ContentHelper.sanitizer = klass.safe_list_sanitizer.new
+      end
+    end
   end
 end

guides/source/configuring.md

@@ -63,6 +63,7 @@ Below are the default values associated with each target version. In cases of co
 - [`config.action_controller.allow_deprecated_parameters_hash_equality`](#config-action-controller-allow-deprecated-parameters-hash-equality): `false`
 - [`config.action_dispatch.debug_exception_log_level`](#config-action-dispatch-debug-exception-log-level): `:error`
 - [`config.action_dispatch.default_headers`](#config-action-dispatch-default-headers): `{ "X-Frame-Options" => "SAMEORIGIN", "X-XSS-Protection" => "0", "X-Content-Type-Options" => "nosniff", "X-Permitted-Cross-Domain-Policies" => "none", "Referrer-Policy" => "strict-origin-when-cross-origin" }`
+- [`config.action_text.sanitizer_vendor`](#config-action-text-sanitizer-vendor): `Rails::HTML::Sanitizer.best_supported_vendor`
 - [`config.action_view.sanitizer_vendor`](#config-action-view-sanitizer-vendor): `Rails::HTML::Sanitizer.best_supported_vendor`
 - [`config.active_job.use_big_decimal_serializer`](#config-active-job-use-big-decimal-serializer): `true`
 - [`config.active_record.allow_deprecated_singular_associations_name`](#config-active-record-allow-deprecated-singular-associations-name): `false`
@@ -2821,6 +2822,17 @@ has no effect if Sprockets is not used. The default value is `true`.
 
 Accepts a string for the HTML tag used to wrap attachments. Defaults to `"action-text-attachment"`.
 
+#### `config.action_text.sanitizer_vendor`
+
+Configures the HTML sanitizer used by Action Text by setting `ActionText::ContentHelper.sanitizer` to an instance of the class returned from the vendor's `.safe_list_sanitizer` method. The default value depends on the `config.load_defaults` target version:
+
+| Starting with version | The default value is                 | Which parses markup as |
+|-----------------------|--------------------------------------|------------------------|
+| (original)            | `Rails::HTML4::Sanitizer`            | HTML4                  |
+| 7.1                   | `Rails::HTML5::Sanitizer` (see NOTE) | HTML5                  |
+
+NOTE: `Rails::HTML5::Sanitizer` is not supported on JRuby, so on JRuby platforms Rails will fall back to use `Rails::HTML4::Sanitizer`.
+
 ### Configuring a Database
 
 Just about every Rails application will interact with a database. You can connect to the database by setting an environment variable `ENV['DATABASE_URL']` or by using a configuration file called `config/database.yml`.

railties/lib/rails/application/configuration.rb

@@ -319,6 +319,10 @@ def load_defaults(target_version)
             if respond_to?(:action_view)
               action_view.sanitizer_vendor = Rails::HTML::Sanitizer.best_supported_vendor
             end
+
+            if respond_to?(:action_text)
+              action_text.sanitizer_vendor = Rails::HTML::Sanitizer.best_supported_vendor
+            end
           end
         else
           raise "Unknown version #{target_version.to_s.inspect}"

railties/lib/rails/generators/rails/app/templates/config/initializers/new_framework_defaults_7_1.rb.tt

@@ -184,13 +184,23 @@
 # Configure Action View to use HTML5 standards-compliant sanitizers when they are supported on your
 # platform.
 #
-# `Rails::HTML::Sanitizer.best_supported_vendor` will return `Rails::HTML5::Sanitizer` if it's
-# supported, else fall back to `Rails::HTML4::Sanitizer`.
+# `Rails::HTML::Sanitizer.best_supported_vendor` will cause Action View to use HTML5-compliant
+# sanitizers if they are supported, else fall back to HTML4 sanitizers.
 #
-# In previous versions of Rails, Action View always used `Rails::HTML4::Sanitizer`.
+# In previous versions of Rails, Action View always used `Rails::HTML4::Sanitizer` as its vendor.
 #
 # Rails.application.config.action_view.sanitizer_vendor = Rails::HTML::Sanitizer.best_supported_vendor
 
+# Configure Action Text to use an HTML5 standards-compliant sanitizer when it is supported on your
+# platform.
+#
+# `Rails::HTML::Sanitizer.best_supported_vendor` will cause Action Text to use HTML5-compliant
+# sanitizers if they are supported, else fall back to HTML4 sanitizers.
+#
+# In previous versions of Rails, Action Text always used `Rails::HTML4::Sanitizer` as its vendor.
+#
+# Rails.application.config.action_text.sanitizer_vendor = Rails::HTML::Sanitizer.best_supported_vendor
+
 # Configure the log level used by the DebugExceptions middleware when logging
 # uncaught exceptions during requests
 # Rails.application.config.action_dispatch.debug_exception_log_level = :error

railties/test/application/configuration_test.rb

@@ -23,7 +23,13 @@ def self.delivered_email(email); email; end
 
 class ::MyOtherMailObserver < ::MyMailObserver; end
 
-class ::MySanitizerVendor < ::Rails::HTML::Sanitizer; end
+class ::MySafeListSanitizer < Rails::HTML4::SafeListSanitizer; end
+
+class ::MySanitizerVendor < ::Rails::HTML::Sanitizer
+  def self.safe_list_sanitizer
+    ::MySafeListSanitizer
+  end
+end
 
 class MyLogRecorder < Logger
   def initialize
@@ -4504,6 +4510,36 @@ def new(app); self; end
       assert_equal ::MySanitizerVendor, ActionView::Helpers::SanitizeHelper.sanitizer_vendor
     end
 
+    test "Action Text uses the best supported safe list sanitizer in new apps" do
+      app "development"
+
+      assert_kind_of(
+        Rails::HTML::Sanitizer.best_supported_vendor.safe_list_sanitizer,
+        ActionText::ContentHelper.sanitizer,
+      )
+    end
+
+    test "Action Text uses the HTML4 safe list sanitizer in upgraded apps" do
+      remove_from_config '.*config\.load_defaults.*\n'
+      add_to_config 'config.load_defaults "7.0"'
+      app "development"
+
+      assert_kind_of(
+        Rails::HTML4::Sanitizer.safe_list_sanitizer,
+        ActionText::ContentHelper.sanitizer,
+      )
+    end
+
+    test "Action Text uses the specified vendor's safe list sanitizer" do
+      add_to_config "config.action_text.sanitizer_vendor = ::MySanitizerVendor"
+      app "development"
+
+      assert_kind_of(
+        ::MySafeListSanitizer,
+        ActionText::ContentHelper.sanitizer,
+      )
+    end
+
     private
       def set_custom_config(contents, config_source = "custom".inspect)
         app_file "config/custom.yml", contents