diff --git a/activerecord/lib/active_record/connection_handling.rb b/activerecord/lib/active_record/connection_handling.rb
index 777cb8a402757d9a32c88b114fed1787cc62e723..3ce9aad5fc20a609e6399269a35cc9d96bc60736 100644
--- a/activerecord/lib/active_record/connection_handling.rb
+++ b/activerecord/lib/active_record/connection_handling.rb
@@ -107,7 +107,7 @@ def connects_to(database: {})
     #   end
     def connected_to(database: nil, role: nil, &blk)
       if database && role
-        raise ArgumentError, "connected_to can only accept a database or role argument, but not both arguments."
+        raise ArgumentError, "connected_to can only accept a `database` or a `role` argument, but not both arguments."
       elsif database
         if database.is_a?(Hash)
           role, database = database.first
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 0e4ea62113ee39cf4e9f12c7045d1ff3e664e297..a394430dfe7d29e9dba5e673e198a956347660ad 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
@@ -153,6 +153,20 @@ def test_switching_connections_with_database_config_hash
           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"
 
@@ -207,6 +221,27 @@ def test_connects_to_using_top_level_key_in_two_level_config
           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