With RSpec, how to seed the database on load?

In spec_helper.rb or rails_helper.rb:

RSpec.configure do |config|
  config.before(:suite) do
    Rails.application.load_seed # loading seeds
  end
end

However Scott's solution surely works for you, I believe the better way to solve your problem was to put the code responsible for seeding your test database within RSpec's configure block:

I use SeedFu and in my spec_helper I have:

RSpec.configure do |config|

  # some other configuration code ...

  config.before(:suite) do
    # ...
    SeedFu.seed
    # ...
  end

  # some other configuration code ...

end

I've followed the raging debate over at Auto-load the seed data from db/seeds.rb with rake. Die-hards maintain that you should never load seed data for tests, but I take the more moderate stance that there are occasions where you might want to load seed data for specific tests, e.g. verifying that the seed data exists.

Unlike some answers given here, I do not recommend unconditionally loading the seeds from inside your spec_helper file. Instead, you can load your seeds using before :each or before :all inside just those test files that need the seeds, e.g.:

describe "db seed tests" do
  before(:each) do
    load "#{Rails.root}/db/seeds.rb" 
  end

  ...your test code here...
end

update

As @marzapower points out, if you go this route, your seeds.db file should clear each table before creating entries or use find_or_create_by methods. (Hint: the former is faster and more reliable.) This will prevent duplicate entries if you load the seeds.db file more than once.