Effective Testing with RSpec 3

Isolating Your Specs Using Database Transactions

To solve this issue, we’re going to wrap each spec in a database transaction. After each example runs, we want RSpec to roll back the transaction, canceling any writes that happened and leaving the database in a clean state. Sequel provides a test-friendly method for wrapping code in transactions.^[44]

An RSpec around hook would be perfect for this task. You already have a spec/support/db.rb file for database support code, so add it there, inside the RSpec.configure block:

06-integration-specs/07/expense_tracker/spec/support/db.rb

c.around(:example, :db) do |example|
  DB.transaction(rollback: :always) { example.run }
end

The sequence of calls in the new hook is a bit twisty, so bear ...