SKILL.md
Seed Database
Manage development and test data effectively.
Quick Reference
| Use | Solution |
|---|---|
| Static reference data | db/seeds.rb with findorcreate_by! |
| Test scenarios | FactoryBot in spec/factories/ |
| Complex relationships | Both combined |
HARD-GATE
NEVER commit production data to seeds
ALWAYS use factories for test-specific scenarios
ALWAYS make seeds idempotent (can run multiple times safely)
NEVER hardcode credentials (passwords, API keys, secrets) in seeds, factories, or examples
- Use ENV variables (e.g., ENV.fetch('DEFAULT_SEED_PASSWORD')) or SecureRandom.hex(16) for non-production data
- Use `rails credentials:edit` to manage production secrets, never commit them in code
Core Process
- Write idempotent seeds — use
findorcreate_by!so re-runs are safe. - Scope by environment — guard non-production data with
Rails.envchecks. - Run seeds — execute
rails db:seed(orrails db:setupfor a fresh database). - Validate idempotency — run
rails db:seeda second time and confirm no duplicates or errors. - Verify data — open
rails consoleand spot-check expected records exist with correct attributes.
Minimal Inline Example
A copy-paste ready db/seeds.rb covering idempotency, environment scoping, and safe credentials:
# db/seeds.rb
# Static reference data — safe to run repeatedly
Role.find_or_create_by!(name: 'admin') do |r|
r.description = 'Full system access'
end
Role.find_or_create_by!(name: 'member') do |r|
r.description = 'Standard user access'
end
# Development-only seed data — never runs in production
if Rails.env.development?
User.find_or_create_by!(email: '[email protected]') do |u|
u.role = Role.find_by!(name: 'admin')
u.password = ENV.fetch('DEFAULT_SEED_PASSWORD', SecureRandom.hex(16))
end
end
For FactoryBot factory definitions and more complex relationship patterns, see [EXAMPLES.md](EXAMPLES.md).
Extended Resources (Progressive Disclosure)
Load these files only when their specific content is needed:
- [EXAMPLES.md](EXAMPLES.md) — Use when you need complete seeding examples with environment-specific patterns and FactoryBot factory definitions
- [references/workflow.md](references/workflow.md) — Use when implementing complex seeding workflows or migration-dependent seed data
Output Style
- Use idiomatic Rails seeding patterns.
- Structure factories clearly.
- Follow the credential and idempotency rules in HARD-GATE without exception.
- Include verification commands:
rails db:seed, a second idempotency run, and arails consolespot-check. - Language — Must be in English unless explicitly requested otherwise.
Integration
| Skill | When to chain |
|---|---|
| write-tests | When setting up test scenarios |
| review-migration | When ensuring DB schema is aligned |