Ensure ActiveRecord::Encryption.config is always ready before access.

Previously, ActiveRecord::Encryption configuration was deferred until
ActiveRecord::Base was loaded. Therefore, accessing
ActiveRecord::Encryption.config properties before ActiveRecord::Base was
loaded would give incorrect results.

ActiveRecord::Encryption now has its own loading hook so that its
configuration is set as soon as needed.

When ActiveRecord::Base is loaded, even lazily, it in turn triggers the
loading of ActiveRecord::Encryption, thus preserving the original
behavior of having its config ready before any use of
ActiveRecord::Base.

Author: maximerety

activerecord/CHANGELOG.md

@@ -1,3 +1,18 @@
+*   Ensure `ActiveRecord::Encryption.config` is always ready before access.
+
+    Previously, `ActiveRecord::Encryption` configuration was deferred until `ActiveRecord::Base`
+    was loaded. Therefore, accessing `ActiveRecord::Encryption.config` properties before
+    `ActiveRecord::Base` was loaded would give incorrect results.
+
+    `ActiveRecord::Encryption` now has its own loading hook so that its configuration is set as
+    soon as needed.
+
+    When `ActiveRecord::Base` is loaded, even lazily, it in turn triggers the loading of
+    `ActiveRecord::Encryption`, thus preserving the original behavior of having its config ready
+    before any use of `ActiveRecord::Base`.
+
+    *Maxime Réty*
+
 *   Add `TimeZoneConverter#==` method, so objects will be properly compared by
     their type, scale, limit & precision.
 

activerecord/lib/active_record/encryption.rb

@@ -53,4 +53,6 @@ def self.eager_load!
       Cipher.eager_load!
     end
   end
+
+  ActiveSupport.run_load_hooks :active_record_encryption, Encryption
 end

activerecord/lib/active_record/railtie.rb

@@ -356,16 +356,19 @@ class Railtie < Rails::Railtie # :nodoc:
     end
 
     initializer "active_record_encryption.configuration" do |app|
-      ActiveSupport.on_load(:active_record) do
-        ActiveRecord::Encryption.configure \
+      ActiveSupport.on_load(:active_record_encryption) do
+        ActiveRecord::Encryption.configure(
           primary_key: app.credentials.dig(:active_record_encryption, :primary_key),
           deterministic_key: app.credentials.dig(:active_record_encryption, :deterministic_key),
           key_derivation_salt: app.credentials.dig(:active_record_encryption, :key_derivation_salt),
           **app.config.active_record.encryption
+        )
 
         auto_filtered_parameters = ActiveRecord::Encryption::AutoFilteredParameters.new(app)
         auto_filtered_parameters.enable if ActiveRecord::Encryption.config.add_to_filter_parameters
+      end
 
+      ActiveSupport.on_load(:active_record) do
         # Support extended queries for deterministic attributes and validations
         if ActiveRecord::Encryption.config.extend_queries
           ActiveRecord::Encryption::ExtendedDeterministicQueries.install_support

guides/source/configuring.md

@@ -3755,6 +3755,7 @@ These are the load hooks you can use in your own code. To hook into the initiali
 | `ActiveModel::Model`                 | `active_model`                       |
 | `ActiveModel::Translation`           | `active_model_translation`           |
 | `ActiveRecord::Base`                 | `active_record`                      |
+| `ActiveRecord::Encryption`           | `active_record_encryption`           |
 | `ActiveRecord::TestFixtures`         | `active_record_fixtures`             |
 | `ActiveRecord::ConnectionAdapters::PostgreSQLAdapter`    | `active_record_postgresqladapter`    |
 | `ActiveRecord::ConnectionAdapters::Mysql2Adapter`        | `active_record_mysql2adapter`        |

railties/test/application/configuration_test.rb

@@ -3731,6 +3731,29 @@ class Post < ActiveRecord::Base
       assert_not_includes ActiveRecord::Base.filter_attributes, :content
     end
 
+    test "ActiveRecord::Encryption.config is ready when accessed before loading ActiveRecord::Base" do
+      add_to_config <<-RUBY
+        config.enable_reloading = false
+        config.eager_load = false
+
+        config.active_record.encryption.primary_key = "dummy_key"
+        config.active_record.encryption.extend_queries = true
+      RUBY
+
+      app "development"
+
+      # Encryption config is ready to be accessed
+      assert_equal "dummy_key", ActiveRecord::Encryption.config.primary_key
+      assert ActiveRecord::Encryption.config.extend_queries
+
+      # ActiveRecord::Base is not loaded yet (lazy loading preserved)
+      active_record_loaded = ActiveRecord.autoload?(:Base).nil?
+      assert_not active_record_loaded
+
+      # When ActiveRecord::Base loaded, extended queries should be installed
+      assert ActiveRecord::Base.include?(ActiveRecord::Encryption::ExtendedDeterministicQueries::CoreQueries)
+    end
+
     test "ActiveRecord::Encryption.config is ready for encrypted attributes when app is lazy loaded" do
       add_to_config <<-RUBY
         config.enable_reloading = false