Improve availability validator spec readability and remove unnecessary expect statements

spec/models/spree/stock/availability_validator_spec.rb

@@ -9,16 +9,11 @@ module Spree
         let(:order) { create(:order_with_line_items) }
         let(:line_item) { order.line_items.first }
 
-        before do
-          expect(order.shipment.inventory_units).to be_empty
-          expect(line_item.target_shipment).to be_nil
-        end
-
         context "available quantity when variant.on_hand > line_item.quantity" do
           it "suceeds" do
             line_item.quantity = line_item.variant.on_hand - 1
             validator.validate(line_item)
-            expect(line_item.errors[:quantity].size).to eq(0)
+            expect(line_item).to be_valid
           end
         end
 
@@ -26,14 +21,14 @@ module Spree
           it "fails" do
             line_item.quantity = line_item.variant.on_hand + 1
             validator.validate(line_item)
-            expect_product_out_of_stock_error
+            expect(line_item).not_to be_valid
           end
 
           it "succeeds with line_item skip_stock_check" do
             line_item.skip_stock_check = true
             line_item.quantity = line_item.variant.on_hand + 1
             validator.validate(line_item)
-            expect(line_item.errors[:quantity].size).to eq(0)
+            expect(line_item).to be_valid
           end
         end
       end
@@ -42,34 +37,20 @@ module Spree
         let(:order) { create(:completed_order_with_totals) }
         let(:line_item) { order.line_items.first }
 
-        before do
-          expect(line_item.quantity).to eq(1)
-          expect(line_item.variant.on_hand).to eq(4)
-
-          expect(order.shipment.inventory_units).to_not be_empty
-          expect(order.shipment.inventory_units_for(line_item.variant).size).to eq(1)
-        end
-
         context "when adding all variant.on_hand quantity to existing line_item quantity" do
           it "succeeds because it excludes existing inventory units from the validation" do
             line_item.quantity += line_item.variant.on_hand
             validator.validate(line_item)
-            expect(line_item.errors[:quantity].size).to eq(0)
+            expect(line_item).to be_valid
           end
 
           it "fails if one more item is added" do
             line_item.quantity += line_item.variant.on_hand + 1
             validator.validate(line_item)
-            expect_product_out_of_stock_error
+            expect(line_item).not_to be_valid
           end
         end
       end
-
-      def expect_product_out_of_stock_error
-        quantity_error = line_item.errors[:quantity].first
-        expect(quantity_error).to include(line_item.variant.product.name)
-        expect(quantity_error).to include("out of stock")
-      end
     end
   end
 end