Implement shipment reader

- Add shipment object
- Add object to represent invalid shipments
- Implement reader for the csv input format

lib/planet_express.rb

@@ -4,6 +4,10 @@ require 'planet_express/version'
 require 'planet_express/shipping_option'
 require 'planet_express/shipping_option_repository'
 
+require 'planet_express/shipment'
+require 'planet_express/invalid_shipment'
+require 'planet_express/shipment_reader'
+
 module PlanetExpress
   class Error < StandardError; end
   # Your code goes here...

lib/planet_express/invalid_shipment.rb

@@ -0,0 +1,11 @@
+module PlanetExpress
+  class InvalidShipment
+    def initialize(raw_string)
+      @raw_string = raw_string
+    end
+
+    def if_valid(&block)
+      return
+    end
+  end
+end

lib/planet_express/shipment.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+module PlanetExpress
+  class Shipment
+    attr_reader :date, :shipping_option, :discounts
+
+    def initialize(date, shipping_option)
+      @date = date
+      @shipping_option = shipping_option
+      @discounts = []
+    end
+
+    def if_valid(&block)
+      yield self
+    end
+
+    def add_discount(discount)
+      discounts.push(discount)
+    end
+
+    def inspect
+      "#{self.class.name} [#{date} #{shipping_option}]"
+    end
+  end
+end

lib/planet_express/shipment_reader.rb

@@ -0,0 +1,40 @@
+require 'csv'
+
+module PlanetExpress
+  class ShipmentReader
+    include Enumerable
+    attr_reader :input, :shipping_option_repository
+
+    def initialize(input, shipping_option_repository)
+      @input = input
+      @shipping_option_repository = shipping_option_repository
+    end
+
+    def each
+      CSV.new(input, headers: false, col_sep: ' ').each do |row|
+        date = parse_date(row)
+        shipping_option = find_shipping_option(row)
+
+        if date.nil? || shipping_option.nil?
+          yield InvalidShipment.new(row.join(" "))
+        else
+          yield Shipment.new(date, shipping_option)
+        end
+      end
+    end
+
+    private
+
+    def find_shipping_option(row)
+      shipping_option_repository.find_by_provider_and_package_size(row[2], row[1])
+    end
+
+    def parse_date(row)
+      begin
+        return Date.iso8601(row[0])
+      rescue ArgumentError => _e
+        nil
+      end
+    end
+  end
+end

spec/fixtures/shipment_input_file.txt

@@ -0,0 +1,21 @@
+2015-02-01 S MR
+2015-02-02 S MR
+2015-02-03 L LP
+2015-02-05 S LP
+2015-02-06 S MR
+2015-02-06 L LP
+2015-02-07 L MR
+2015-02-08 M MR
+2015-02-09 L LP
+2015-02-10 L LP
+2015-02-10 S MR
+2015-02-10 S MR
+2015-02-11 L LP
+2015-02-12 M MR
+2015-02-13 M LP
+2015-02-15 S MR
+2015-02-17 L LP
+2015-02-17 S MR
+2015-02-24 L LP
+2015-02-29 CUSPS
+2015-03-01 S MR

spec/shipment_reader_spec.rb

@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+RSpec.describe PlanetExpress::ShipmentReader do
+  let(:shipping_option_repsitory) { PlanetExpress::ShippingOptionRepository.new }
+
+  let(:input) { '' }
+
+  subject { PlanetExpress::ShipmentReader.new(input, shipping_option_repsitory) }
+
+  describe '#each' do
+    context 'with a file' do
+      let(:input) { File.read(File.expand_path('../fixtures/shipment_input_file.txt', __FILE__)) }
+      let(:result) { subject.to_a }
+
+      it 'parses the file' do
+        expect(result.length).to eq(21)
+        expect(result.select { |item| item.instance_of?(PlanetExpress::Shipment) }.length).to eq(20)
+        expect(result.select { |item| item.instance_of?(PlanetExpress::InvalidShipment) }.length).to eq(1)
+      end
+    end
+
+    context 'with valid shipment' do
+      let(:input) { '2015-02-01 S MR' }
+
+      let(:result) { subject.to_a }
+      let(:shipment) { result.first }
+
+      it 'returns a parsed shipment' do
+        expect(shipment.date).to eq(Date.new(2015, 2, 1))
+        expect(shipment.shipping_option).to eq(PlanetExpress::ShippingOption.new('MR', 'S', 200))
+      end
+    end
+
+    context 'with an invalid shipment' do
+      let(:input) { '2015-02-29 CUSPS' }
+
+      let(:result) { subject.to_a }
+      let(:shipment) { result.first }
+
+      it 'returns an invalid shipment' do
+        expect(shipment).to be_an_instance_of(PlanetExpress::InvalidShipment)
+      end
+    end
+  end
+end