SimpleCov Rspec coverage not handle prepend files

Question

I am working with Spree gem and Rails 6. I create decorator for Spree::Variant and Spree::Product

variant_decorator.rb:

# frozen_string_literal: true

module Spree
  module VariantDecorator
    def display_price_ca(currency = Spree::Config[:currency])
      price_in(currency, Spree::Country.ca)&.display_price
    end

    def display_price_us(currency = Spree::Config[:currency])
      price_in(currency, Spree::Country.us)&.display_price
    end

    def price_in(currency, country = nil)
      pricess = prices.select { |price| price.currency == currency } || prices.build(currency: currency)
      return pricess.last unless country

      pricess.sort_by { |e| -e[:id] }
             .find { |p| p.country == country }
    end

    def amount_in(currency, country = nil)
      price_in(currency, country).try(:amount)
    end
  end
end

Spree::Variant.prepend Spree::VariantDecorator

product_decorator.rb

# frozen_string_literal: true

module Spree
  module ProductDecorator
    module ClassMethods
      def really_destroy_all
        ClassMethodWorker
          .perform_async(klass: 'Spree::Product',
                         instance_id: Spree::Product.unscoped.pluck(:id),
                         metod: 'really_destroy!')
      end

      def discontinue_on_now!
        unscoped.update_all(discontinue_on: DateTime.current)
      end
    end
    def self.prepended(base)
      class << base
        prepend ClassMethods
      end
      base.validates :price_list_material_id, uniqueness: true
      base.has_many :prices, through: :master
      base.has_many :countries, through: :prices

      base.delegate :display_price_ca, :display_price_us, to: :find_or_build_master
    end
  end
end

Spree::Product.prepend Spree::ProductDecorator

I create simple Rspec for display_price_ca and display_price_us

describe Spree::Product, type: :model do
  context 'product instance' do
    context 'prices' do
      let(:product_ca) { create(:product_ca, country_price: 15) }
      let(:product_us) { create(:product_us, country_price: 25) }
      let(:product_all_country) { create(:product_all_country) }

      it '#display_price_ca' do
        expect(product_ca.display_price_ca.to_s).to eq('$15.00')
        expect(product_all_country.display_price_ca.to_s).to eq('$20.00')
      end

      it '#display_price_us' do
        expect(product_us.display_price_us.to_s).to eq('$25.00')
        expect(product_all_country.display_price_us.to_s).to eq('$10.00')
      end
    end
  end
end

SimpleCov not handle decorators and show to me:

Coverage report generated for RSpec to /data/server-store/coverage. 163 / 1387 LOC (11.75%) covered

I have SimpeCov start in spec_hepler.rb:

require 'simplecov'
SimpleCov.start "rails"

Result for variant_decorator.rb:

I see lines not covered, but it should be covered. What might be a problem and how to fix it? Thanks.

Answer 1

You mentioned that you added the SimpleCov call to spec_helper.rb. If you also have a rails_helper.rb file, and you require that file from your specs, you will need to add the SimpleCov initialization to that file instead. Add it to the very top of the file, before anything else, otherwise your decorator files will not be included.

I'm working on a large Spree-based application and I also ran into this problem.