Using Seed Data with RSpec Stories 17 Jul 2008

Yesterday I needed to introduce seed data into our application. In order for our story suite to continue to run I needed to populate seed data into the testing environment when the stories ran. I didn’t want to use the production seed data in my test environment, but I wanted to keep things simple. I am already using using “seed_fu”:http://github.com/mbleigh/seed-fu/tree from Michael Bleigh to handle the seed data for production. Why not leverage it for stories as well?

I made a minor modification to the task to support passing in an argument to rake or setting an environment variable so you can load “fixtures” from a different directory. In my “stories/helper.rb” file I have added near the top:

system "rake db:seed FIXTURE_PATH=stories/fixtures"

This loads the seed data from “RAILS_ROOT/stories/fixtures”. Here’s the modified seed_fu rake task:

namespace :db do
  desc "Loads seed data from db/fixtures for the current environment."
  task :seed => :environment do
    fixture_path = ENV["FIXTURE_PATH"] ? ENV["FIXTURE_PATH"] : "db/fixtures"
    Dir[File.join(RAILS_ROOT, fixture_path, '\*.rb')].sort.each { |fixture| 
      puts "\n== Seeding from #{File.split(fixture).last} " + \
         ("=" * (60 - (17 + File.split(fixture).last.length)))
      load fixture 
      puts "=" * 60 + "\n"
    }
    Dir[File.join(RAILS_ROOT, fixture_path, RAILS_ENV, '\*.rb')].sort.each { |fixture| 
      puts "\n== [#{RAILS_ENV}] Seeding from #{File.split(fixture).last} " + \
          ("=" * (60 - (20 + File.split(fixture).last.length + RAILS_ENV.length)))
      load fixture 
      puts "=" * 60 + "\n"
    }
  end
end

After this my seed data was resembling the typical format:

ExpenseCategory.transaction do
  ExpenseCategory.seed(:object_code) do |s|
     s.object_code = "1234"
     s.name = "Foo"
  end

  ExpenseCategory.seed(:object_code) do |s|
     s.object_code = "1235"
     s.name = "Bar"
  end

  ExpenseCategory.seed(:object_code) do |s|
     s.object_code = "1236"
     s.name = "Baz"
  end
end

And while I like this it’s a little verbose. So I modified seed_fu to introduce the seed_many method to consolidate that:

ExpenseCategory.transaction do
  ExpenseCategory.seed_many(:object_code, [
     { :object_code => "1234", :name => "Foo"},
     { :object_code => "1235", :name => "Bar"},
     { :object_code => "1236", :name => "Baz"}
  ])
end

It maintains a simple API and highly readable seed data. I’ve committed this to my fork of seed_fu, and am hoping that Michael accepts the patch and adds it to seed_fu.

The patch for the rake FIXTURE_PATH: “http://github.com/zdennis/seed-fu/commit/4d391aa214c369f161e37c194b07d49e55312b35”:http://github.com/zdennis/seed-fu/commit/4d391aa214c369f161e37c194b07d49e55312b35
The patch to add the seed_many method: “http://github.com/zdennis/seed-fu/commit/9f7e8b27b7cb175911474a898ea282771ab2a5c3”:http://github.com/zdennis/seed-fu/commit/9f7e8b27b7cb175911474a898ea282771ab2a5c3