How to properly do model testing with ActiveStorage in rails?

Question

I have just switched to using ActiveStorage on rails 5.1.4 and I am new to TDD and struggling to figure out how to test a model that has_one_attached :avatar

Answer 1

I solved using

FactoryBot.define do
  factory :culture do
    name 'Soy'
    after(:build) do |culture|
      culture.image.attach(io: File.open(Rails.root.join('spec', 'factories', 'images', 'soy.jpeg')), filename: 'soy.jpeg', content_type: 'image/jpeg')
    end
  end
end

After

describe '#image' do
  subject { create(:culture).image }

  it { is_expected.to be_an_instance_of(ActiveStorage::Attached::One) }
end