Added #between method to Sale class

lib/far_mar/Sale.rb

@@ -28,5 +28,17 @@ def vendor
         vendor.id == self.vendor_id
       end
     end
+    def product
+      FarMar::Product.all.find do |product|
+        product.id == self.product_id
+      end
+    end
+    def self.between(beginning_time, end_time)
+      beginning_time = DateTime.strptime(beginning_time, "%Y-%m-%d %H:%M:%S %z")
+      end_time = DateTime.strptime(end_time, "%Y-%m-%d %H:%M:%S %z")
+      self.all.find_all do |sale|
+        sale.purchase_time > beginning_time && sale.purchase_time < end_time
+      end
+    end
   end
 end

spec/far_mar/Sale_spec.rb

@@ -27,4 +27,33 @@
       expect(@sale.vendor.name).to eq "Beer, Heathcote and Leffler"
     end
   end
+  describe ".product" do
+    it "returns the product instance whose id matches the sales's product_id" do
+      expect(@sale.product.id).to eq 2213
+      expect(@sale.product.name).to eq "Rotten Fruit"
+    end
+  end
+  describe "#between(beginning_time, end_time)"do
+    it "returns a collection of sales where the purchase_time is between the two parameters" do
+      begin_time = "2013-11-06 08:47:12 -0800"
+      end_time = "2013-11-06 08:52:59 -0800"
+      expect(FarMar::Sale.between(begin_time, end_time).length).to eq 4
+      expect(FarMar::Sale.between(begin_time, end_time)[1].id).to eq 4119
+      expect(FarMar::Sale.between(begin_time, end_time)[1].class).to eq FarMar::Sale
+    end
+    context "when end_time is before beginning_time" do
+      it "returns an empty array" do
+        begin_time = "2013-11-06 08:52:59 -0800"
+        end_time = "2013-11-06 08:47:12 -0800"
+        expect(FarMar::Sale.between(begin_time, end_time)).to eq []
+      end
+    end
+    context "when beginning_time and end_time are the same" do
+      it "returns an empty array" do
+        begin_time = "2013-11-06 08:47:12 -0800"
+        end_time = "2013-11-06 08:47:12 -0800"
+        expect(FarMar::Sale.between(begin_time, end_time)).to eq []
+      end
+    end
+  end
 end