Wrap Mysql count of deleted rows in lock block to avoid conflict in test

1 files changed, 28 insertions, 0 deletions

diff --git a/activerecord/test/cases/adapters/mysql2/count_deleted_rows_with_lock_test.rb b/activerecord/test/cases/adapters/mysql2/count_deleted_rows_with_lock_test.rb
new file mode 100644
index 0000000000..4d361e405c
--- /dev/null
+++ b/activerecord/test/cases/adapters/mysql2/count_deleted_rows_with_lock_test.rb
@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+require "cases/helper"
+require "support/connection_helper"
+require "models/author"
+require "models/bulb"
+
+module ActiveRecord
+  class CountDeletedRowsWithLockTest < ActiveRecord::Mysql2TestCase
+    test "delete and create in different threads synchronize correctly" do
+      Bulb.unscoped.delete_all
+      Bulb.create!(name: "Jimmy", color: "blue")
+
+      delete_thread = Thread.new do
+        Bulb.unscoped.delete_all
+      end
+
+      create_thread = Thread.new do
+        Author.create!(name: "Tommy")
+      end
+
+      delete_thread.join
+      create_thread.join
+
+      assert_equal 1, delete_thread.value
+    end
+  end
+end