RR has block mode.

rr-blocks.rb

image_a = Image.make
stub(image_a).migrated? { false }
stub(image_a).local_filename { 'spec/fixtures/backdrop.jpg' }

image_b = Image.make
stub(image_b).migrated? { false }
stub(image_b).local_filename { 'spec/fixtures/backdrop.jpg' }

document = Movie.new(:title => 'Test Movie', :images => [image_a, image_b])

mock(Fh::ImageryMigrator).migrate_image(image_a).once
mock(Fh::ImageryMigrator).migrate_image(image_b).once

# ---

stub(image_a = Image.make) do
  migrated? { false }
  local_filename { 'spec/fixtures/backdrop.jpg' }
end

stub(image_b = Image.make) do
  migrated? { false }
  local_filename { 'spec/fixtures/backdrop.jpg' }
end

mock(Fh::ImageryMigrator) do
  migrate_image(image_a).once
  migrate_image(image_b).once
end