Merge pull request rails#47536 from eileencodes/allow-configs_for-to-accept-custom-hash-key-for-lookup

Allow configs_for to accept a custom hash key

Author: eileencodes

activerecord/CHANGELOG.md

@@ -1,3 +1,18 @@
+*   Remove the `:include_replicas` argument from `configs_for`. Use `:include_hidden` argument instead.
+
+    *Eileen M. Uchitelle*
+
+*   Allow applications to lookup a config via a custom hash key.
+
+    If you have registered a custom config or want to find configs where the hash matches a specific key, now you can pass `config_key` to `configs_for`. For example if you have a `db_config` with the key `vitess` you can look up a database configuration hash by  matching that key.
+
+    ```ruby
+    ActiveRecord::Base.configurations.configs_for(env_name: "development", name: "primary", config_key: :vitess)
+    ActiveRecord::Base.configurations.configs_for(env_name: "development", config_key: :vitess)
+    ```
+
+    *Eileen M. Uchitelle*
+
 *   Allow applications to register a custom database configuration handler.
 
     Adds a mechanism for registering a custom handler for cases where you want database configurations to respond to custom methods. This is useful for non-Rails database adapters or tools like Vitess that you may want to configure differently from a standard `HashConfig` or `UrlConfig`.

activerecord/lib/active_record/database_configurations.rb

@@ -82,20 +82,14 @@ def initialize(configurations = {})
     # * <tt>name:</tt> The db config name (i.e. primary, animals, etc.). Defaults
     #   to +nil+. If no +env_name+ is specified the config for the default env and the
     #   passed +name+ will be returned.
-    # * <tt>include_replicas:</tt> Deprecated. Determines whether to include replicas in
-    #   the returned list. Most of the time we're only iterating over the write
-    #   connection (i.e. migrations don't need to run for the write and read connection).
-    #   Defaults to +false+.
+    # * <tt>config_key:</tt> Selects configs that contain a particular key in the configuration
+    #   hash. Useful for selecting configs that use a custom db config handler or finding
+    #   configs with hashes that contain a particular key.
     # * <tt>include_hidden:</tt> Determines whether to include replicas and configurations
     #   hidden by +database_tasks: false+ in the returned list. Most of the time we're only
     #   iterating over the primary connections (i.e. migrations don't need to run for the
     #   write and read connection). Defaults to +false+.
-    def configs_for(env_name: nil, name: nil, include_replicas: false, include_hidden: false)
-      if include_replicas
-        include_hidden = include_replicas
-        ActiveRecord.deprecator.warn("The kwarg `include_replicas` is deprecated in favor of `include_hidden`. When `include_hidden` is passed, configurations with `replica: true` or `database_tasks: false` will be returned. `include_replicas` will be removed in Rails 7.1.")
-      end
-
+    def configs_for(env_name: nil, name: nil, config_key: nil, include_hidden: false)
       env_name ||= default_env if name
       configs = env_with_configs(env_name)
 
@@ -105,6 +99,12 @@ def configs_for(env_name: nil, name: nil, include_replicas: false, include_hidde
         end
       end
 
+      if config_key
+        configs = configs.select do |db_config|
+          db_config.configuration_hash.key?(config_key)
+        end
+      end
+
       if name
         configs.find do |db_config|
           db_config.name == name

activerecord/test/cases/database_configurations_test.rb

@@ -128,16 +128,33 @@ def test_registering_a_custom_config_object
   ensure
     ActiveRecord::DatabaseConfigurations.db_config_handlers = previous_handlers
   end
-end
 
-class LegacyDatabaseConfigurationsTest < ActiveRecord::TestCase
-  def test_unsupported_method_raises
-    assert_raises NoMethodError do
-      ActiveRecord::Base.configurations.fetch(:foo)
+  def test_configs_for_with_custom_key
+    previous_handlers = ActiveRecord::DatabaseConfigurations.db_config_handlers
+
+    ActiveRecord::DatabaseConfigurations.register_db_config_handler do |env_name, name, _, config|
+      next unless config.key?(:custom_config)
+      CustomHashConfig.new(env_name, name, config)
     end
+
+    config = {
+      "default_env" => {
+        "primary" => { "adapter" => "sqlite3", "database" => "test/db/primary.sqlite3", "custom_config" => { "sharded" => 1 } },
+        "replica" => { "adapter" => "sqlite3", "database" => "test/db/hidden.sqlite3", "replica" => true, "custom_config" => { "sharded" => 1 } },
+        "secondary" => { "adapter" => "sqlite3", "database" => "test/db/secondary.sqlite3" }
+      }
+    }
+    prev_configs, ActiveRecord::Base.configurations = ActiveRecord::Base.configurations, config
+
+    assert_equal 1, ActiveRecord::Base.configurations.configs_for(env_name: "default_env", config_key: :custom_config).count
+    assert_equal 2, ActiveRecord::Base.configurations.configs_for(env_name: "default_env", config_key: :custom_config, include_hidden: true).count
+    assert_equal 2, ActiveRecord::Base.configurations.configs_for(env_name: "default_env").count
+  ensure
+    ActiveRecord::DatabaseConfigurations.db_config_handlers = previous_handlers
+    ActiveRecord::Base.configurations = prev_configs
   end
 
-  def test_hidden_returns_replicas
+  def test_configs_for_with_include_hidden
     config = {
       "default_env" => {
         "readonly" => { "adapter" => "sqlite3", "database" => "test/db/readonly.sqlite3", "replica" => true },
@@ -152,12 +169,4 @@ def test_hidden_returns_replicas
   ensure
     ActiveRecord::Base.configurations = prev_configs
   end
-
-  def test_include_replicas_is_deprecated
-    assert_deprecated(ActiveRecord.deprecator) do
-      db_config = ActiveRecord::Base.configurations.configs_for(env_name: "arunit", name: "primary", include_replicas: true)
-
-      assert_equal "primary", db_config.name
-    end
-  end
 end

guides/source/7_1_release_notes.md

@@ -89,6 +89,8 @@ Please refer to the [Changelog][active-record] for detailed changes.
 
 * Remove support for `ActiveRecord.legacy_connection_handling`.
 
+* Remove support for `:include_replicas` on `configs_for`. Use `:include_hidden` instead.
+
 ### Deprecations
 
 ### Notable changes