Merge pull request rails#50093 from kmcphillips/ar-adapter-alias

Delay validation of registered Active Record adapters and allow aliasing of adapters

Author: byroot

activerecord/lib/active_record/connection_adapters.rb

@@ -18,15 +18,15 @@ class << self
       #   ActiveRecord::ConnectionAdapters.register("mysql", "ActiveRecord::ConnectionAdapters::TrilogyAdapter", "active_record/connection_adapters/trilogy_adapter")
       #
       def register(name, class_name, path = class_name.underscore)
-        @adapters[name] = [class_name, path]
+        @adapters[name.to_s] = [class_name, path]
       end
 
       def resolve(adapter_name) # :nodoc:
         # Require the adapter itself and give useful feedback about
         #   1. Missing adapter gems.
         #   2. Incorrectly registered adapters.
         #   3. Adapter gems' missing dependencies.
-        class_name, path_to_adapter = @adapters[adapter_name]
+        class_name, path_to_adapter = @adapters[adapter_name.to_s]
 
         unless class_name
           raise AdapterNotFound, <<~MSG.squish

activerecord/lib/active_record/connection_adapters/abstract/connection_handler.rb

@@ -322,7 +322,7 @@ def disconnect_pool_from_pool_manager(pool_manager, role, shard)
         #
         def resolve_pool_config(config, connection_name, role, shard)
           db_config = Base.configurations.resolve(config)
-
+          db_config.validate!
           raise(AdapterNotSpecified, "database configuration does not specify adapter") unless db_config.adapter
           ConnectionAdapters::PoolConfig.new(connection_name, db_config, role, shard)
         end

activerecord/lib/active_record/database_configurations/database_config.rb

@@ -8,12 +8,6 @@ class DatabaseConfigurations
     class DatabaseConfig # :nodoc:
       attr_reader :env_name, :name
 
-      def self.new(...)
-        instance = super
-        instance.adapter_class if instance.adapter # Ensure resolution happens early
-        instance
-      end
-
       def initialize(env_name, name)
         @env_name = env_name
         @name = name
@@ -28,6 +22,12 @@ def new_connection
         adapter_class.new(configuration_hash)
       end
 
+      def validate!
+        adapter_class if adapter
+
+        true
+      end
+
       def host
         raise NotImplementedError
       end

activerecord/test/cases/connection_adapters/connection_handler_test.rb

@@ -63,6 +63,20 @@ def test_establish_connection_using_3_levels_config
         ENV["RAILS_ENV"] = previous_env
       end
 
+      def test_validates_db_configuration_and_raises_on_invalid_adapter
+        config = {
+          "development" => { "adapter" => "ridiculous" },
+        }
+
+        @prev_configs, ActiveRecord::Base.configurations = ActiveRecord::Base.configurations, config
+
+        assert_raises(ActiveRecord::AdapterNotFound) do
+          ActiveRecord::Base.establish_connection(:development)
+        end
+      ensure
+        ActiveRecord::Base.configurations = @prev_configs
+      end
+
       unless in_memory_db?
         def test_not_setting_writing_role_while_using_another_named_role_raises
           connection_handler = ActiveRecord::Base.connection_handler

activerecord/test/cases/connection_adapters/registration_test.rb

@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+require "cases/helper"
+
+module ActiveRecord
+  module ConnectionAdapters
+    class RegistrationTest < ActiveRecord::TestCase
+      def setup
+        @original_adapters = ActiveRecord::ConnectionAdapters.instance_variable_get(:@adapters).dup
+        ActiveRecord::ConnectionAdapters.instance_variable_get(:@adapters).delete("fake")
+        @fake_adapter_path = File.expand_path("../../support/fake_adapter.rb", __dir__)
+      end
+
+      def teardown
+        ActiveRecord::ConnectionAdapters.instance_variable_set(:@adapters, @original_adapters)
+      end
+
+      test "#register registers a new database adapter and #resolve can find it and raises if it cannot" do
+        assert_raises(ActiveRecord::AdapterNotFound) do
+          ActiveRecord::ConnectionAdapters.resolve("fake")
+        end
+
+        ActiveRecord::ConnectionAdapters.register("fake", "FakeActiveRecordAdapter", @fake_adapter_path)
+
+        assert_equal "FakeActiveRecordAdapter", ActiveRecord::ConnectionAdapters.resolve("fake").name
+      end
+
+      test "#register allows for symbol key" do
+        assert_raises(ActiveRecord::AdapterNotFound) do
+          ActiveRecord::ConnectionAdapters.resolve("fake")
+        end
+
+        ActiveRecord::ConnectionAdapters.register(:fake, "FakeActiveRecordAdapter", @fake_adapter_path)
+
+        assert_equal "FakeActiveRecordAdapter", ActiveRecord::ConnectionAdapters.resolve("fake").name
+      end
+
+      test "#resolve allows for symbol key" do
+        assert_raises(ActiveRecord::AdapterNotFound) do
+          ActiveRecord::ConnectionAdapters.resolve("fake")
+        end
+
+        ActiveRecord::ConnectionAdapters.register("fake", "FakeActiveRecordAdapter", @fake_adapter_path)
+
+        assert_equal "FakeActiveRecordAdapter", ActiveRecord::ConnectionAdapters.resolve(:fake).name
+      end
+    end
+  end
+end

activerecord/test/cases/database_configurations/hash_config_test.rb

@@ -145,6 +145,15 @@ def test_schema_cache_path_configuration_hash
         config = HashConfig.new("default_env", "primary", { schema_cache_path: "db/config_schema_cache.yml", adapter: "abstract" })
         assert_equal "db/config_schema_cache.yml", config.schema_cache_path
       end
+
+      def test_validate_checks_the_adapter_exists
+        config = HashConfig.new("default_env", "primary", adapter: "abstract")
+        assert config.validate!
+        config = HashConfig.new("default_env", "primary", adapter: "potato")
+        assert_raises(ActiveRecord::AdapterNotFound) do
+          config.validate!
+        end
+      end
     end
   end
 end

railties/lib/rails/commands/dbconsole/dbconsole_command.rb

@@ -37,6 +37,8 @@ def db_config
           "#{missing_db} configured for '#{environment}'. Available configuration: #{configurations.inspect}"
       end
 
+      @db_config.validate!
+
       @db_config
     end
 
@@ -51,7 +53,7 @@ def environment
     private
       def adapter_class
         ActiveRecord::ConnectionAdapters.resolve(db_config.adapter)
-      rescue LoadError, ActiveRecord::AdapterNotFound
+      rescue LoadError
         ActiveRecord::ConnectionAdapters::AbstractAdapter
       end
 

railties/test/application/configuration_test.rb

@@ -4770,6 +4770,27 @@ class Foo < ApplicationRecord
       assert_equal [:foo], Foo.attributes_for_inspect
     end
 
+    test "new Active Record connection adapters can be registered as aliases in application initializers" do
+      app_file "config/database.yml", <<-YAML
+        development:
+          adapter: potato
+          database: 'example_db'
+      YAML
+
+      app_file "config/initializers/active_record_connection_adapters.rb", <<-RUBY
+        ActiveRecord::ConnectionAdapters.register(
+          "potato",
+          "ActiveRecord::ConnectionAdapters::SQLite3Adapter",
+          "active_record/connection_adapters/sqlite3_adapter"
+        )
+      RUBY
+
+      app "development"
+
+      assert_equal "potato", ActiveRecord::Base.connection.pool.db_config.adapter
+      assert_equal "SQLite", ActiveRecord::Base.connection.adapter_name
+    end
+
     private
       def set_custom_config(contents, config_source = "custom".inspect)
         app_file "config/custom.yml", contents