Factory Bot is a fixtures replacement which can generate the needed records directly in the tests. Faker can be used to create fake data for these records.
Create Acceptance Tests or Feature Tests to extend your automated tests with browser testing. It can help tests some areas that cannot be reached with other types of tests.
Using ActionMailer::Preview preview email samples without sending them. Using Zurb's Foundation for Emails, learn how to use email templates with the Ink framework.
Using the Rails 5.1.X defaults, we have a look at what is configured and explore the different types of tests; using the provided MiniTest and Capybara.