seed_fixtures

Use your seeds.rb as fixtures when running tests.

Read the back story of this gem: https://ghiculescu.substack.com/p/using-realistic-development-and-test

Currently only Rails 7 is supported. PRs to support older Rails versions are welcome!

1. Add seed_fixtures to the test group of your Gemfile, then run bundle install.

2. In your test_helper.rb:

class ActiveSupport::TestCase
  # Add this line:
  fixtures_from_seeds

  # Comment out or remove this line:
  # fixtures :all
end

Notes:

• You cannot use standard Rails fixtures if you are using this gem. Make sure you remove the fixtures call that's included in test_helper.rb by default!
• Ensure your test_helper.rb includes this: require "rails/test_help".

3. Add .seeds_hash to your .gitignore file.

• When tests run, the contents of db/seeds.rb will be loaded into the test database.
• To improve performance, keeps a hash of everything your app's db/ folder in the .seeds_hash file. This way, seeds are only reloaded into the database if you change your seeds file or your schema.
• Adds a parallel_setup hook, so if you run parallel tests, seeds will be loaded correctly. (This is needed because parallel databases are truncated before each run.)

Just like anything else in the database...

user = User.find_by(name: "Alex")

Or if you like, define helper methods for easy lookup.

module SeedFixtureLookups
  def user_alex
    @user_alex ||= User.where(name: "Alex").sole
  end
end

class ActiveSupport::TestCase
  include SeedFixtureLookups
end

# in a test...
test "alex exists" do
  assert_not_nil user_alex
end

Not everyone agrees this is a good idea. And for many apps, it's not! But for some apps it is a very neat way of writing a robust test suite. If your app is one of those, give this a try.

There's more back story on the gem here: https://ghiculescu.substack.com/p/using-realistic-development-and-test

The gem is available as open source under the terms of the MIT License.