Merge pull request #25107 from Erol/introduce-new-ar-transaction-error-classes

Introduce new ActiveRecord transaction error classes

Closes #26018

3 files changed, 17 insertions, 4 deletions

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 610d78245f..acc21866f1 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -753,7 +753,7 @@ module ActiveRecord
         when ER_DATA_TOO_LONG
           ValueTooLong.new(message)
         when ER_LOCK_DEADLOCK
-          TransactionSerializationError.new(message)
+          DeadlockDetected.new(message)
         else
           super
         end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 61a980fda9..e213c991c8 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -407,6 +407,7 @@ module ActiveRecord
         FOREIGN_KEY_VIOLATION = "23503"
         UNIQUE_VIOLATION      = "23505"
         SERIALIZATION_FAILURE = "40001"
+        DEADLOCK_DETECTED     = "40P01"
 
         def translate_exception(exception, message)
           return exception unless exception.respond_to?(:result)
@@ -419,7 +420,9 @@ module ActiveRecord
           when VALUE_LIMIT_VIOLATION
             ValueTooLong.new(message)
           when SERIALIZATION_FAILURE
-            TransactionSerializationError.new(message)
+            SerializationFailure.new(message)
+          when DEADLOCK_DETECTED
+            DeadlockDetected.new(message)
           else
             super
           end
diff --git a/activerecord/lib/active_record/errors.rb b/activerecord/lib/active_record/errors.rb
index 26146dbce7..3f75ce4099 100644
--- a/activerecord/lib/active_record/errors.rb
+++ b/activerecord/lib/active_record/errors.rb
@@ -285,14 +285,24 @@ module ActiveRecord
   class TransactionIsolationError < ActiveRecordError
   end
 
-  # TransactionSerializationError will be raised when a transaction is rolled
+  # TransactionRollbackError will be raised when a transaction is rolled
   # back by the database due to a serialization failure or a deadlock.
   #
   # See the following:
   #
   # * http://www.postgresql.org/docs/current/static/transaction-iso.html
   # * https://dev.mysql.com/doc/refman/5.7/en/error-messages-server.html#error_er_lock_deadlock
-  class TransactionSerializationError < StatementInvalid
+  class TransactionRollbackError < StatementInvalid
+  end
+
+  # SerializationFailure will be raised when a transaction is rolled
+  # back by the database due to a serialization failure.
+  class SerializationFailure < TransactionRollbackError
+  end
+
+  # DeadlockDetected will be raised when a transaction is rolled
+  # back by the database when a deadlock is encountered.
+  class DeadlockDetected < TransactionRollbackError
   end
 
   # IrreversibleOrderError is raised when a relation's order is too complex for