Should test actual error which is raised from the database

1 files changed, 23 insertions, 1 deletions

diff --git a/activerecord/test/cases/adapters/mysql2/transaction_test.rb b/activerecord/test/cases/adapters/mysql2/transaction_test.rb
index 25d9f69a89..7b032fed6d 100644
--- a/activerecord/test/cases/adapters/mysql2/transaction_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/transaction_test.rb
@@ -62,7 +62,29 @@ module ActiveRecord
 
     test "raises TransactionTimeout when mysql raises ER_LOCK_WAIT_TIMEOUT" do
       assert_raises(ActiveRecord::TransactionTimeout) do
-        ActiveRecord::Base.connection.execute("SIGNAL SQLSTATE 'HY000' SET MESSAGE_TEXT = 'Testing error', MYSQL_ERRNO = 1205;")
+        s = Sample.create!(value: 1)
+        latch1 = Concurrent::CountDownLatch.new
+        latch2 = Concurrent::CountDownLatch.new
+
+        thread = Thread.new do
+          Sample.transaction do
+            Sample.lock.find(s.id)
+            latch1.count_down
+            latch2.wait
+          end
+        end
+
+        begin
+          Sample.transaction do
+            latch1.wait
+            Sample.connection.execute("SET innodb_lock_wait_timeout = 1")
+            Sample.lock.find(s.id)
+          end
+        ensure
+          Sample.connection.execute("SET innodb_lock_wait_timeout = DEFAULT")
+          latch2.count_down
+          thread.join
+        end
       end
     end
   end