Question

My app has what is effectively a constant database table. It’s big — it contains ~125K rows of 14 fields — and rebuilding it takes about five minutes.

For development and production work, I rebuild as part of seeding the database. But for testing, I don’t want to wait five minutes every time I run the tests.

What technique or workflow would you suggest in this case? (One approach might be to alias development_constant_table as test_constant_table for the duration of the tests, if that’s possible.)

update

I should mention that db/seeds.rb file looks something like this:

# file: db/seeds.rb
require "#{Rails.root}/db/time_dimension_loader"
TimeDimensionLoader.perform_lengthy_table_creation

Answer 1

Okay, Tony Hopkinson’s pointer to stackoverflow.com/questions/1574797/ pointed the way.

First, create a rake file:

# lib/tasks/test_seed.rake
namespace :db do 
  namespace :test do
    task :prepare => :environment do
      Rake::Task["db:seed"].invoke
    end
  end
end

Then when you invoke the standard rake db:test:prepare, your new rake task gets executed after the standard db:test:prepare runs. So yes, it takes a while to run the rake task, but thereafter the table is present (and persists) so you don’t have to rebuild the table every time you run RSpec or autotest.