Also handle ActiveRecord::DatabaseConnectionError

lib/activerecord/mysql/reconnect.rb

@@ -26,6 +26,7 @@ module Activerecord::Mysql::Reconnect
 
   HANDLE_ERROR = [
     ActiveRecord::ConnectionNotEstablished,
+    ActiveRecord::DatabaseConnectionError,
     ActiveRecord::StatementInvalid,
     Mysql2::Error,
   ]
@@ -47,6 +48,7 @@ module Activerecord::Mysql::Reconnect
     lost_connection: "Lost connection to MySQL server at 'reading initial communication packet'",
     not_connected: "MySQL client is not connected",
     killed: 'Connection was killed',
+    issue_connecting: 'There is an issue connecting with your hostname',
   }
 
   READ_SQL_REGEXP = /\A\s*(?:SELECT|SHOW|SET)\b/i

spec/activerecord-mysql-reconnect_spec.rb

@@ -452,62 +452,49 @@
     end
 
     let(:mysql_error) do
-      Mysql2::Error.const_defined?(:ConnectionError) ? Mysql2::Error::ConnectionError : Mysql2::Error
+      Mysql2::Error::ConnectionError
     end
 
     before do
       allow_any_instance_of(mysql_error).to receive(:message).and_return('Lost connection to MySQL server during query')
+      allow_any_instance_of(ActiveRecord::StatementInvalid).to receive(:message).and_return('Lost connection to MySQL server during query')
+      allow_any_instance_of(ActiveRecord::DatabaseConnectionError).to receive(:message).and_return('Lost connection to MySQL server during query')
     end
 
     context "when retry failed " do
       specify do
-        if ActiveRecord::VERSION::MAJOR < 6
-          expect(ActiveRecord::Base.logger).to receive(:warn).with(warning_template % [
-            "MySQL server has gone away. Trying to reconnect in 0.5 seconds.",
-            "#{mysql_error}: Lost connection to MySQL server during query: SELECT `employees`.* FROM `employees` [ActiveRecord::StatementInvalid]",
-          ])
-        else
-          expect(ActiveRecord::Base.logger).to receive(:warn).with(warning_template % [
-            "MySQL server has gone away. Trying to reconnect in 0.5 seconds.",
-            "#{mysql_error}: Lost connection to MySQL server during query [ActiveRecord::StatementInvalid]",
-          ])
-        end
-
+        expect(ActiveRecord::Base.logger).to receive(:warn).with(warning_template % [
+          "MySQL server has gone away. Trying to reconnect in 0.5 seconds.",
+          "Lost connection to MySQL server during query [ActiveRecord::StatementInvalid]",
+        ])
 
         (1.0..4.5).step(0.5).each do |sec|
           expect(ActiveRecord::Base.logger).to receive(:warn).with(warning_template % [
             "MySQL server has gone away. Trying to reconnect in #{sec} seconds.",
-            "Lost connection to MySQL server during query [#{mysql_error}]",
+            "Lost connection to MySQL server during query [ActiveRecord::DatabaseConnectionError]",
           ])
         end
 
         expect(ActiveRecord::Base.logger).to receive(:warn).with(warning_template % [
           "Query retry failed.",
-          "Lost connection to MySQL server during query [#{mysql_error}]",
+          "Lost connection to MySQL server during query [ActiveRecord::DatabaseConnectionError]",
         ])
 
         expect(Employee.all.length).to eq 1000
         MysqlServer.stop
 
         expect {
           Employee.all.length
-        }.to raise_error(mysql_error)
+        }.to raise_error(ActiveRecord::DatabaseConnectionError)
       end
     end
 
     context "when retry succeeded" do
       specify do
-        if ActiveRecord::VERSION::MAJOR < 6
-          expect(ActiveRecord::Base.logger).to receive(:warn).with(warning_template % [
-            "MySQL server has gone away. Trying to reconnect in 0.5 seconds.",
-            "#{mysql_error}: Lost connection to MySQL server during query: SELECT `employees`.* FROM `employees` [ActiveRecord::StatementInvalid]",
-          ])
-        else
-          expect(ActiveRecord::Base.logger).to receive(:warn).with(warning_template % [
-            "MySQL server has gone away. Trying to reconnect in 0.5 seconds.",
-            "#{mysql_error}: Lost connection to MySQL server during query [ActiveRecord::StatementInvalid]",
-          ])
-        end
+        expect(ActiveRecord::Base.logger).to receive(:warn).with(warning_template % [
+          "MySQL server has gone away. Trying to reconnect in 0.5 seconds.",
+          "Lost connection to MySQL server during query [ActiveRecord::StatementInvalid]",
+        ])
 
         expect(Employee.all.length).to eq 1000
         MysqlServer.restart