Register trainee teachers - Testing Data Migrations

Data migrations should be tested against production-like data.

1. Deploy to productiondata
2. Check that the deployment ran successfully and the data migration happened
3. Do any necessary checks on productiondata to ensure that the data has been changed as expected

RSpec tests

Where a migration has logic beyond looping a list and updating records, it is good practice to include a service within the migration and write a test for the service. An example is:

• add_ethnicity_to_teach_first_trainees_spec.rb
• 20231214132713_add_ethnicity_to_teach_first_trainees.rb