Freeze ADAPTER_NAME in adapters

activerecord/lib/active_record/connection_adapters/abstract_adapter.rb

@@ -66,6 +66,7 @@ module ConnectionAdapters # :nodoc:
     # Most of the methods in the adapter are useful during migrations. Most
     # notably, the instance methods provided by SchemaStatement are very useful.
     class AbstractAdapter
+      ADAPTER_NAME = 'Abstract'.freeze
       include Quoting, DatabaseStatements, SchemaStatements
       include DatabaseLimits
       include QueryCache
@@ -167,7 +168,7 @@ def unprepared_statement
       # Returns the human-readable name of the adapter. Use mixed case - one
       # can always use downcase if needed.
       def adapter_name
-        'Abstract'
+        self.class::ADAPTER_NAME
       end
 
       # Does this adapter support migrations?

activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb

@@ -162,10 +162,6 @@ def initialize(connection, logger, connection_options, config)
         end
       end
 
-      def adapter_name #:nodoc:
-        self.class::ADAPTER_NAME
-      end
-
       # Returns true, since this connection adapter supports migrations.
       def supports_migrations?
         true

activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb

@@ -29,7 +29,7 @@ def mysql2_connection(config)
 
   module ConnectionAdapters
     class Mysql2Adapter < AbstractMysqlAdapter
-      ADAPTER_NAME = 'Mysql2'
+      ADAPTER_NAME = 'Mysql2'.freeze
 
       def initialize(connection, logger, connection_options, config)
         super

activerecord/lib/active_record/connection_adapters/mysql_adapter.rb

@@ -66,7 +66,7 @@ module ConnectionAdapters
     # * <tt>:sslcipher</tt> - Necessary to use MySQL with an SSL connection.
     #
     class MysqlAdapter < AbstractMysqlAdapter
-      ADAPTER_NAME = 'MySQL'
+      ADAPTER_NAME = 'MySQL'.freeze
 
       class StatementPool < ConnectionAdapters::StatementPool
         def initialize(connection, max = 1000)

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -74,7 +74,7 @@ module ConnectionAdapters
     # In addition, default connection parameters of libpq can be set per environment variables.
     # See http://www.postgresql.org/docs/9.1/static/libpq-envars.html .
     class PostgreSQLAdapter < AbstractAdapter
-      ADAPTER_NAME = 'PostgreSQL'
+      ADAPTER_NAME = 'PostgreSQL'.freeze
 
       NATIVE_DATABASE_TYPES = {
         primary_key: "serial primary key",
@@ -118,11 +118,6 @@ class PostgreSQLAdapter < AbstractAdapter
       include PostgreSQL::DatabaseStatements
       include Savepoints
 
-      # Returns 'PostgreSQL' as adapter name for identification purposes.
-      def adapter_name
-        ADAPTER_NAME
-      end
-
       def schema_creation # :nodoc:
         PostgreSQL::SchemaCreation.new self
       end

activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb

@@ -67,6 +67,7 @@ def type_cast_for_database(value)
     #
     # * <tt>:database</tt> - Path to the database file.
     class SQLite3Adapter < AbstractAdapter
+      ADAPTER_NAME = 'SQLite'.freeze
       include Savepoints
 
       NATIVE_DATABASE_TYPES = {
@@ -147,10 +148,6 @@ def initialize(connection, logger, connection_options, config)
         end
       end
 
-      def adapter_name #:nodoc:
-        'SQLite'
-      end
-
       def supports_ddl_transactions?
         true
       end