How do I test and document seeds?

To test and document seeds, use a schema file and nest the configurations under a seeds: key

Example

seeds/schema.yml

version: 2

seeds:
  - name: country_codes
    description: A mapping of two letter country codes to country names
    columns:
      - name: country_code
        tests:
          - unique
          - not_null
      - name: country_name
        tests:
          - unique
          - not_null