1 files changed, 93 insertions, 3 deletions
diff --git a/activerecord/test/cases/connection_adapters/connection_handlers_multi_db_test.rb b/activerecord/test/cases/connection_adapters/connection_handlers_multi_db_test.rb
index a520fb1303..393b577c1d 100644
--- a/activerecord/test/cases/connection_adapters/connection_handlers_multi_db_test.rb
+++ b/activerecord/test/cases/connection_adapters/connection_handlers_multi_db_test.rb
@@ -127,6 +127,9 @@ module ActiveRecord
           ActiveRecord::Base.connected_to(database: { writing: "postgres://localhost/bar" }) do
             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)
@@ -136,25 +139,54 @@ module ActiveRecord
 
         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" }
+          config = { adapter: "sqlite3", database: "db/readonly.sqlite3" }
 
           ActiveRecord::Base.connected_to(database: { writing: config }) do
             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"
 
-          ActiveRecord::Base.connected_to(database: :arunit2) do
+          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
             handler = ActiveRecord::Base.connection_handler
-            assert_equal handler, ActiveRecord::Base.connection_handlers[:arunit2]
+            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
@@ -189,6 +221,27 @@ module ActiveRecord
           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
@@ -227,6 +280,43 @@ module ActiveRecord
         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
     end
   end
 end