Seed Database

Manage development and test data effectively.

Quick Reference

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

1. Write idempotent seeds — use find_or_create_by! so re-runs are safe.
2. Scope by environment — guard non-production data with Rails.env checks.
3. Run seeds — execute rails db:seed (or rails db:setup for a fresh database).
4. Validate idempotency — run rails db:seed a second time and confirm no duplicates or errors.
5. Verify data — open rails console and spot-check expected records exist with correct attributes.

Extended Resources

Environment-Specific Seeds Use find_or_create_by! to keep seeds idempotent — safe to run multiple times.

# db/seeds.rb
if Rails.env.development?
  require Rails.root.join('db/seeds/development')
elsif Rails.env.test?
  require Rails.root.join('db/seeds/test')
end

# db/seeds/development.rb
10.times do |i|
  email = "dev_user_#{i + 1}@example.com"

  User.find_or_create_by!(email: email) do |u|
    u.password = ENV.fetch('DEFAULT_SEED_PASSWORD', SecureRandom.hex(16))
  end
end

FactoryBot Factory Example

# spec/factories/users.rb
FactoryBot.define do
  factory :user do
    email { Faker::Internet.unique.email }
    password { ENV.fetch('DEFAULT_SEED_PASSWORD', SecureRandom.hex(16)) }

    trait :admin do
      admin { true }
    end
  end
end

• SKILL.md
• EXAMPLES.md
• references/workflow.md
• FactoryBot documentation
• Faker gem
• Rails Seeding Guide

Output Style

1. Use idiomatic Rails seeding patterns.
2. Structure factories clearly.
3. Ensure no credentials are leaked.
4. Include a production-secret note: use rails credentials:edit for production secrets and never commit them in seeds, factories, examples, logs, or docs.
5. Include verification commands: rails db:seed, a second idempotency run, and a rails console spot-check.
6. Language — Must be in English unless explicitly requested otherwise.

Integration