spec_helper.rb

  config.use_transactional_fixtures = false

  config.before(:suite) do
    DatabaseCleaner.clean_with :truncation
  end

  config.before(:each) do
    DatabaseCleaner.strategy = :transaction
  end

  config.before(:each, js: true) do
    DatabaseCleaner.strategy = :truncation
  end

  config.before(:each) do
    DatabaseCleaner.start
  end

  # Force the driver to wait till the page finishes loading
  config.after(:each, js: true) do
    current_path.should == current_path
  end

  config.after(:each) do
    DatabaseCleaner.clean
  end

BTW, @jnicklas also suggests using an :around block for database cleaning. teamcapybara/capybara#1089 (comment)