connection_handlers_multi_db_test.rb

# frozen_string_literal: true

require "cases/helper"
require "models/person"

module ActiveRecord
  module ConnectionAdapters
    class ConnectionHandlersMultiDbTest < ActiveRecord::TestCase
      self.use_transactional_tests = false

      fixtures :people

      def setup
        @handlers = { writing: ConnectionHandler.new, reading: ConnectionHandler.new }
        @rw_handler = @handlers[:writing]
        @ro_handler = @handlers[:reading]
        @spec_name = "primary"
        @rw_pool = @handlers[:writing].establish_connection(ActiveRecord::Base.configurations["arunit"])
        @ro_pool = @handlers[:reading].establish_connection(ActiveRecord::Base.configurations["arunit"])
      end

      def teardown
        ActiveRecord::Base.connection_handlers = { writing: ActiveRecord::Base.default_connection_handler }
      end

      class MultiConnectionTestModel < ActiveRecord::Base
      end

      def test_multiple_connection_handlers_works_in_a_threaded_environment
        tf_writing = Tempfile.open "test_writing"
        tf_reading = Tempfile.open "test_reading"

        MultiConnectionTestModel.connects_to database: { writing: { database: tf_writing.path, adapter: "sqlite3" }, reading: { database: tf_reading.path, adapter: "sqlite3" } }

        MultiConnectionTestModel.connection.execute("CREATE TABLE `test_1` (connection_role VARCHAR (255))")
        MultiConnectionTestModel.connection.execute("INSERT INTO test_1 VALUES ('writing')")

        ActiveRecord::Base.connected_to(role: :reading) do
          MultiConnectionTestModel.connection.execute("CREATE TABLE `test_1` (connection_role VARCHAR (255))")
          MultiConnectionTestModel.connection.execute("INSERT INTO test_1 VALUES ('reading')")
        end

        read_latch = Concurrent::CountDownLatch.new
        write_latch = Concurrent::CountDownLatch.new

        MultiConnectionTestModel.connection

        thread = Thread.new do
          MultiConnectionTestModel.connection

          write_latch.wait
          assert_equal "writing", MultiConnectionTestModel.connection.select_value("SELECT connection_role from test_1")
          read_latch.count_down
        end

        ActiveRecord::Base.connected_to(role: :reading) do
          write_latch.count_down
          assert_equal "reading", MultiConnectionTestModel.connection.select_value("SELECT connection_role from test_1")
          read_latch.wait
        end

        thread.join
      ensure
        tf_reading.close
        tf_reading.unlink
        tf_writing.close
        tf_writing.unlink
      end

      unless in_memory_db?
        def test_establish_connection_using_3_levels_config
          previous_env, ENV["RAILS_ENV"] = ENV["RAILS_ENV"], "default_env"

          config = {
            "default_env" => {
              "readonly" => { "adapter" => "sqlite3", "database" => "db/readonly.sqlite3" },
              "primary"  => { "adapter" => "sqlite3", "database" => "db/primary.sqlite3" }
            }
          }
          @prev_configs, ActiveRecord::Base.configurations = ActiveRecord::Base.configurations, config

          ActiveRecord::Base.connects_to(database: { writing: :primary, reading: :readonly })

          assert_not_nil pool = ActiveRecord::Base.connection_handlers[:writing].retrieve_connection_pool("primary")
          assert_equal "db/primary.sqlite3", pool.spec.config[:database]

          assert_not_nil pool = ActiveRecord::Base.connection_handlers[:reading].retrieve_connection_pool("primary")
          assert_equal "db/readonly.sqlite3", pool.spec.config[:database]
        ensure
          ActiveRecord::Base.configurations = @prev_configs
          ActiveRecord::Base.establish_connection(:arunit)
          ENV["RAILS_ENV"] = previous_env
        end

        def test_switching_connections_via_handler
          previous_env, ENV["RAILS_ENV"] = ENV["RAILS_ENV"], "default_env"

          config = {
            "default_env" => {
              "readonly" => { "adapter" => "sqlite3", "database" => "db/readonly.sqlite3" },
              "primary"  => { "adapter" => "sqlite3", "database" => "db/primary.sqlite3" }
            }
          }
          @prev_configs, ActiveRecord::Base.configurations = ActiveRecord::Base.configurations, config

          ActiveRecord::Base.connects_to(database: { writing: :primary, reading: :readonly })

          ActiveRecord::Base.connected_to(role: :reading) do
            @ro_handler = ActiveRecord::Base.connection_handler
            assert_equal ActiveRecord::Base.connection_handler, ActiveRecord::Base.connection_handlers[:reading]
            assert ActiveRecord::Base.connected_to?(role: :reading)
            assert_not ActiveRecord::Base.connected_to?(role: :writing)
          end

          ActiveRecord::Base.connected_to(role: :writing) do
            assert_equal ActiveRecord::Base.connection_handler, ActiveRecord::Base.connection_handlers[:writing]
            assert_not_equal @ro_handler, ActiveRecord::Base.connection_handler
            assert ActiveRecord::Base.connected_to?(role: :writing)
            assert_not ActiveRecord::Base.connected_to?(role: :reading)
          end
        ensure
          ActiveRecord::Base.configurations = @prev_configs
          ActiveRecord::Base.establish_connection(:arunit)
          ENV["RAILS_ENV"] = previous_env
        end

        def test_switching_connections_with_database_url
          previous_env, ENV["RAILS_ENV"] = ENV["RAILS_ENV"], "default_env"
          previous_url, ENV["DATABASE_URL"] = ENV["DATABASE_URL"], "postgres://localhost/foo"

          ActiveRecord::Base.connected_to(database: { writing: "postgres://localhost/bar" }) do
            assert ActiveRecord::Base.connected_to?(role: :writing)

            handler = ActiveRecord::Base.connection_handler
            assert_equal handler, ActiveRecord::Base.connection_handlers[:writing]

            assert_not_nil pool = handler.retrieve_connection_pool("primary")
            assert_equal({ adapter: "postgresql", database: "bar", host: "localhost" }, pool.spec.config)
          end
        ensure
          ActiveRecord::Base.establish_connection(:arunit)
          ENV["RAILS_ENV"] = previous_env
          ENV["DATABASE_URL"] = previous_url
        end

        def test_switching_connections_with_database_config_hash
          previous_env, ENV["RAILS_ENV"] = ENV["RAILS_ENV"], "default_env"
          config = { adapter: "sqlite3", database: "db/readonly.sqlite3" }

          ActiveRecord::Base.connected_to(database: { writing: config }) do
            assert ActiveRecord::Base.connected_to?(role: :writing)

            handler = ActiveRecord::Base.connection_handler
            assert_equal handler, ActiveRecord::Base.connection_handlers[:writing]

            assert_not_nil pool = handler.retrieve_connection_pool("primary")
            assert_equal(config, pool.spec.config)
          end
        ensure
          ActiveRecord::Base.establish_connection(:arunit)
          ENV["RAILS_ENV"] = previous_env
        end

        def test_switching_connections_with_database_and_role_raises
          error = assert_raises(ArgumentError) do
            ActiveRecord::Base.connected_to(database: :readonly, role: :writing) { }
          end
          assert_equal "connected_to can only accept a `database` or a `role` argument, but not both arguments.", error.message
        end

        def test_switching_connections_without_database_and_role_raises
          error = assert_raises(ArgumentError) do
            ActiveRecord::Base.connected_to { }
          end
          assert_equal "must provide a `database` or a `role`.", error.message
        end

        def test_switching_connections_with_database_symbol
          previous_env, ENV["RAILS_ENV"] = ENV["RAILS_ENV"], "default_env"

          config = {
            "default_env" => {
              "readonly" => { adapter: "sqlite3", database: "db/readonly.sqlite3" },
              "primary"  => { adapter: "sqlite3", database: "db/primary.sqlite3" }
            }
          }
          @prev_configs, ActiveRecord::Base.configurations = ActiveRecord::Base.configurations, config

          ActiveRecord::Base.connected_to(database: :readonly) do
            assert ActiveRecord::Base.connected_to?(role: :readonly)

            handler = ActiveRecord::Base.connection_handler
            assert_equal handler, ActiveRecord::Base.connection_handlers[:readonly]

            assert_not_nil pool = handler.retrieve_connection_pool("primary")
            assert_equal(config["default_env"]["readonly"], pool.spec.config)
          end
        ensure
          ActiveRecord::Base.configurations = @prev_configs
          ActiveRecord::Base.establish_connection(:arunit)
          ENV["RAILS_ENV"] = previous_env
        end

        def test_connects_to_with_single_configuration
          config = {
            "development" => { "adapter" => "sqlite3", "database" => "db/primary.sqlite3" },
          }
          @prev_configs, ActiveRecord::Base.configurations = ActiveRecord::Base.configurations, config

          ActiveRecord::Base.connects_to database: { writing: :development }

          assert_equal 1, ActiveRecord::Base.connection_handlers.size
          assert_equal ActiveRecord::Base.connection_handler, ActiveRecord::Base.connection_handlers[:writing]
          assert ActiveRecord::Base.connected_to?(role: :writing)
        ensure
          ActiveRecord::Base.configurations = @prev_configs
          ActiveRecord::Base.establish_connection(:arunit)
        end

        def test_connects_to_using_top_level_key_in_two_level_config
          config = {
            "development" => { "adapter" => "sqlite3", "database" => "db/primary.sqlite3" },
            "development_readonly" => { "adapter" => "sqlite3", "database" => "db/readonly.sqlite3" }
          }
          @prev_configs, ActiveRecord::Base.configurations = ActiveRecord::Base.configurations, config

          ActiveRecord::Base.connects_to database: { writing: :development, reading: :development_readonly }

          assert_not_nil pool = ActiveRecord::Base.connection_handlers[:reading].retrieve_connection_pool("primary")
          assert_equal "db/readonly.sqlite3", pool.spec.config[:database]
        ensure
          ActiveRecord::Base.configurations = @prev_configs
          ActiveRecord::Base.establish_connection(:arunit)
        end

        def test_connects_to_returns_array_of_established_connections
          config = {
            "development" => { "adapter" => "sqlite3", "database" => "db/primary.sqlite3" },
            "development_readonly" => { "adapter" => "sqlite3", "database" => "db/readonly.sqlite3" }
          }
          @prev_configs, ActiveRecord::Base.configurations = ActiveRecord::Base.configurations, config

          result = ActiveRecord::Base.connects_to database: { writing: :development, reading: :development_readonly }

          assert_equal(
            [
              ActiveRecord::Base.connection_handlers[:writing].retrieve_connection_pool("primary"),
              ActiveRecord::Base.connection_handlers[:reading].retrieve_connection_pool("primary")
            ],
            result
          )
        ensure
          ActiveRecord::Base.configurations = @prev_configs
          ActiveRecord::Base.establish_connection(:arunit)
        end
      end

      def test_connection_pools
        assert_equal([@rw_pool], @handlers[:writing].connection_pools)
        assert_equal([@ro_pool], @handlers[:reading].connection_pools)
      end

      def test_retrieve_connection
        assert @rw_handler.retrieve_connection(@spec_name)
        assert @ro_handler.retrieve_connection(@spec_name)
      end

      def test_active_connections?
        assert_not_predicate @rw_handler, :active_connections?
        assert_not_predicate @ro_handler, :active_connections?

        assert @rw_handler.retrieve_connection(@spec_name)
        assert @ro_handler.retrieve_connection(@spec_name)

        assert_predicate @rw_handler, :active_connections?
        assert_predicate @ro_handler, :active_connections?

        @rw_handler.clear_active_connections!
        assert_not_predicate @rw_handler, :active_connections?

        @ro_handler.clear_active_connections!
        assert_not_predicate @ro_handler, :active_connections?
      end

      def test_retrieve_connection_pool
        assert_not_nil @rw_handler.retrieve_connection_pool(@spec_name)
        assert_not_nil @ro_handler.retrieve_connection_pool(@spec_name)
      end

      def test_retrieve_connection_pool_with_invalid_id
        assert_nil @rw_handler.retrieve_connection_pool("foo")
        assert_nil @ro_handler.retrieve_connection_pool("foo")
      end

      def test_connection_handlers_are_per_thread_and_not_per_fiber
        original_handlers = ActiveRecord::Base.connection_handlers

        ActiveRecord::Base.connection_handlers = { writing: ActiveRecord::Base.default_connection_handler, reading: ActiveRecord::ConnectionAdapters::ConnectionHandler.new }

        reading_handler = ActiveRecord::Base.connection_handlers[:reading]

        reading = ActiveRecord::Base.with_handler(:reading) do
          Person.connection_handler
        end

        assert_not_equal reading, ActiveRecord::Base.connection_handler
        assert_equal reading, reading_handler
      ensure
        ActiveRecord::Base.connection_handlers = original_handlers
      end

      def test_connection_handlers_swapping_connections_in_fiber
        original_handlers = ActiveRecord::Base.connection_handlers

        ActiveRecord::Base.connection_handlers = { writing: ActiveRecord::Base.default_connection_handler, reading: ActiveRecord::ConnectionAdapters::ConnectionHandler.new }

        reading_handler = ActiveRecord::Base.connection_handlers[:reading]

        enum = Enumerator.new do |r|
          r << ActiveRecord::Base.connection_handler
        end

        reading = ActiveRecord::Base.with_handler(:reading) do
          enum.next
        end

        assert_equal reading, reading_handler
      ensure
        ActiveRecord::Base.connection_handlers = original_handlers
      end

      def test_calling_connected_to_on_a_non_existent_handler_raises
        error = assert_raises ArgumentError do
          ActiveRecord::Base.connected_to(role: :reading) do
            yield
          end
        end

        assert_equal "The reading role does not exist. Add it by establishing a connection with `connects_to` or use an existing role (writing).", error.message
      end
    end
  end
end