cart_calculator_spec.rb

gistfile1.txt

require_relative "cart_calculator"

RSpec.describe CartCalculator do
  let(:products) do
    [
      { name: "Book", price: 20 },
      { name: "Pen", price: 5 },
      { name: "Notebook", price: 15 }
    ]
  end

  describe "#calculate_total" do
    it "calculates basic total without discounts" do
      calculator = CartCalculator.new(products)
      result = calculator.calculate_total

      expect(result[:subtotal]).to eq(40)
      expect(result[:discount]).to eq(0)
      expect(result[:shipping]).to eq(10)
      expect(result[:total]).to eq(50)
    end

    it "applies free shipping for orders over $50" do
      expensive_products = [
        { name: "Premium Book", price: 60 }
      ]
      calculator = CartCalculator.new(expensive_products)
      result = calculator.calculate_total

      expect(result[:shipping]).to eq(0)
    end

    it "applies bulk discount for orders over $100" do
      bulk_products = [
        { name: "Premium Book", price: 120 }
      ]
      calculator = CartCalculator.new(bulk_products)
      result = calculator.calculate_total

      expect(result[:discount]).to eq(12) # 10% of 120
      expect(result[:total]).to eq(108) # 120 - 12 (no shipping, over $50)
    end
  end
end