Consistently extract checking version for all adapters

I don't prefer to extract it for one adapter even though all adapters
also does.

Related to #34227.

4 files changed, 29 insertions, 27 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index fa10f18cb7..0fe868478c 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -125,6 +125,8 @@ module ActiveRecord
         @advisory_locks_enabled = self.class.type_cast_config_to_boolean(
           config.fetch(:advisory_locks, true)
         )
+
+        check_version
       end
 
       def replica?
@@ -502,6 +504,9 @@ module ActiveRecord
       end
 
       private
+        def check_version
+        end
+
         def type_map
           @type_map ||= Type::TypeMap.new.tap do |mapping|
             initialize_type_map(mapping)
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index 5ad3fdbb88..cb5eeb64dd 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -26,7 +26,6 @@ module ActiveRecord
       #   ActiveRecord::ConnectionAdapters::Mysql2Adapter.emulate_booleans = false
       class_attribute :emulate_booleans, default: true
 
-      SUPPORTED_VERSION = "5.5.8"
       NATIVE_DATABASE_TYPES = {
         primary_key: "bigint auto_increment PRIMARY KEY",
         string:      { name: "varchar", limit: 255 },
@@ -55,7 +54,6 @@ module ActiveRecord
         super(connection, logger, config)
 
         @statements = StatementPool.new(self.class.type_cast_config_to_integer(config[:statement_limit]))
-        check_version
       end
 
       def version #:nodoc:
@@ -532,16 +530,13 @@ module ActiveRecord
         end
       end
 
-      protected
-
+      private
         def check_version
-          if version < SUPPORTED_VERSION
-            raise "Your version of MySQL (#{version_string}) is too old. Active Record supports " \
-                  "MySQL >= #{SUPPORTED_VERSION}."
+          if version < "5.5.8"
+            raise "Your version of MySQL (#{version_string}) is too old. Active Record supports MySQL >= 5.5.8."
           end
         end
 
-      private
         def combine_multi_statements(total_sql)
           total_sql.each_with_object([]) do |sql, total_sql_chunks|
             previous_packet = total_sql_chunks.last
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index bc6eb11572..a280ca500a 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -43,9 +43,14 @@ module ActiveRecord
       valid_conn_param_keys = PG::Connection.conndefaults_hash.keys + [:requiressl]
       conn_params.slice!(*valid_conn_param_keys)
 
-      # The postgres drivers don't allow the creation of an unconnected PG::Connection object,
-      # so just pass a nil connection object for the time being.
-      ConnectionAdapters::PostgreSQLAdapter.new(nil, logger, conn_params, config)
+      conn = PG.connect(conn_params)
+      ConnectionAdapters::PostgreSQLAdapter.new(conn, logger, conn_params, config)
+    rescue ::PG::Error => error
+      if error.message.include?("does not exist")
+        raise ActiveRecord::NoDatabaseError
+      else
+        raise
+      end
     end
   end
 
@@ -220,15 +225,11 @@ module ActiveRecord
         @local_tz = nil
         @max_identifier_length = nil
 
-        connect
+        configure_connection
         add_pg_encoders
         @statements = StatementPool.new @connection,
                                         self.class.type_cast_config_to_integer(config[:statement_limit])
 
-        if postgresql_version < 90100
-          raise "Your version of PostgreSQL (#{postgresql_version}) is too old. Active Record supports PostgreSQL >= 9.1."
-        end
-
         add_pg_decoders
 
         @type_map = Type::HashLookupTypeMap.new
@@ -410,6 +411,12 @@ module ActiveRecord
       end
 
       private
+        def check_version
+          if postgresql_version < 90100
+            raise "Your version of PostgreSQL (#{postgresql_version}) is too old. Active Record supports PostgreSQL >= 9.1."
+          end
+        end
+
         # See https://www.postgresql.org/docs/current/static/errcodes-appendix.html
         VALUE_LIMIT_VIOLATION = "22001"
         NUMERIC_VALUE_OUT_OF_RANGE = "22003"
@@ -699,12 +706,6 @@ module ActiveRecord
         def connect
           @connection = PG.connect(@connection_parameters)
           configure_connection
-        rescue ::PG::Error => error
-          if error.message.include?("does not exist")
-            raise ActiveRecord::NoDatabaseError
-          else
-            raise
-          end
         end
 
         # Configures the encoding, verbosity, schema search path, and time zone of the connection.
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index 81882f6cc1..e0355a316b 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -105,11 +105,6 @@ module ActiveRecord
 
         @active     = true
         @statements = StatementPool.new(self.class.type_cast_config_to_integer(config[:statement_limit]))
-
-        if sqlite_version < "3.8.0"
-          raise "Your version of SQLite (#{sqlite_version}) is too old. Active Record supports SQLite >= 3.8."
-        end
-
         configure_connection
       end
 
@@ -401,6 +396,12 @@ module ActiveRecord
       end
 
       private
+        def check_version
+          if sqlite_version < "3.8.0"
+            raise "Your version of SQLite (#{sqlite_version}) is too old. Active Record supports SQLite >= 3.8."
+          end
+        end
+
         def initialize_type_map(m = type_map)
           super
           register_class_with_limit m, %r(int)i, SQLite3Integer