I just got AWDWR, second edition. I wanted to bone up on migrations, so I read the part of page 79 that starts with "Let's create a data-only migration" and happily walks you through the generation of a migration called add_test_data.
Later, in the migrations chapter on page 273, the book shows a generation of a migration called load_users_data. At the bottom of the page there is the dire warning: "Be warned: the only data you should load in migrations is data that you'll also want to see in production ... Do not load test data into your application this way."
These are seemingly contradictory. I don't see any further clarification in the book.
Is there a way to create a test-data-only migration that doesn't get inserted into the migration versioning system?