Write a spec covering the race condition during group deletion.

- Use multiple threads / database connections to:

  1. Escape the transaction the spec seems to be running
     in (`config.use_transactional_fixtures` is off, but
     `ActiveRecord::Base.connection.open_transactions` is not empty
     at the beginning of the spec.

  2. Simulate a Sidekiq worker performing the hard delete outside of the
     soft-delete transaction.

- The spec is a little clunky, but it was the smallest thing I could get
  working - and even this took a couple of hours. Let me know if you
  have any suggestions to improve it!

1 files changed, 9 insertions, 0 deletions

diff --git a/spec/support/database_connection_helpers.rb b/spec/support/database_connection_helpers.rb
new file mode 100644
index 00000000000..763329499f0
--- /dev/null
+++ b/spec/support/database_connection_helpers.rb
@@ -0,0 +1,9 @@
+module DatabaseConnectionHelpers
+  def run_with_new_database_connection
+    pool = ActiveRecord::Base.connection_pool
+    conn = pool.checkout
+    yield conn
+  ensure
+    pool.checkin(conn)
+  end
+end