parsley/spec/models/recipe_spec.rb

require 'rails_helper'

RSpec.describe Recipe, type: :model do
  describe '#update_rating!' do

    it 'should set rating to nil with no ratings' do
      r = create(:recipe)
      r.update_rating!
      expect(r.rating).to be_nil

      create(:log, rating: nil, source_recipe: r)

      r.update_rating!
      expect(r.rating).to be_nil
    end

    it 'should set rating based on user logs' do
      user = create(:user)
      other_user = create(:user)
      r = create(:recipe, user: user)
      create(:log, rating: 2, source_recipe: r, user: user)
      create(:log, rating: 4, source_recipe: r, user: user)
      create(:log, rating: 5, source_recipe: r, user: other_user)

      r.update_rating!

      expect(r.rating).to eq 3
    end

  end
end