Merge pull request rails#54959 from flavorjones/flavorjones/run-hook-for-database-configurations

Add a load hook for `ActiveRecord::DatabaseConfigurations`

Author: byroot

activerecord/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Add a load hook `active_record_database_configurations` for `ActiveRecord::DatabaseConfigurations`
+
+    *Mike Dalessio*
+
 *   Use `TRUE` and `FALSE` for SQLite queries with boolean columns.
 
     *Hartley McGuire*

activerecord/lib/active_record/database_configurations.rb

@@ -36,9 +36,11 @@ class InvalidConfigurationError < StandardError; end
     # to respond to `sharded?`. To implement this define the following in an
     # initializer:
     #
-    #   ActiveRecord::DatabaseConfigurations.register_db_config_handler do |env_name, name, url, config|
-    #     next unless config.key?(:vitess)
-    #     VitessConfig.new(env_name, name, config)
+    #   ActiveSupport.on_load(:active_record_database_configurations) do
+    #     ActiveRecord::DatabaseConfigurations.register_db_config_handler do |env_name, name, url, config|
+    #       next unless config.key?(:vitess)
+    #       VitessConfig.new(env_name, name, config)
+    #     end
     #   end
     #
     # Note: applications must handle the condition in which custom config should be
@@ -306,4 +308,6 @@ def environment_value_for(name)
         url
       end
   end
+
+  ActiveSupport.run_load_hooks(:active_record_database_configurations, DatabaseConfigurations)
 end

guides/source/configuring.md

@@ -3820,6 +3820,7 @@ 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::DatabaseConfigurations` | `active_record_database_configurations` |
 | `ActiveRecord::Encryption`           | `active_record_encryption`           |
 | `ActiveRecord::TestFixtures`         | `active_record_fixtures`             |
 | `ActiveRecord::ConnectionAdapters::PostgreSQLAdapter`    | `active_record_postgresqladapter`    |