issue #112 - managed to replicate ingredient subtraction issue in mod…

…el test. The short circuit in the sub() function in ingredient doesn't appear to actually avoid hitting the false state where the whole ingredient is removed. Not sure why. Research required on short circuiting functions via returns in ruby.

spec/models/meal_plan_spec.rb

@@ -17,6 +17,11 @@
   let(:recipe_unitless_2) { FactoryGirl.create(:recipe, user: user1, ingredients_block: "3 apples") }
   let(:recipe5) { FactoryGirl.create(:recipe, user: user1, ingredients_block: "4 pounds of apples") }
   let(:recipe6) { FactoryGirl.create(:recipe, user: user1, ingredients_block: "4 grams of apples") }
+
+  let(:recipe7) { FactoryGirl.create(:recipe, user: user1) }
+  let(:recipe8) { FactoryGirl.create(:recipe, user: user1) }
+  let(:recipe9) { FactoryGirl.create(:recipe, user: user1) }
+
   let(:mealplan1) { FactoryGirl.create(:meal_plan, user: user1) }
 
   it "doesn't crash when subtracting a recipe with a weird unit" do
@@ -92,4 +97,11 @@
     expect(mealplan1.user.grocery_list.ingredients.first.unitized_amount).to_not eq recipe5.ingredients.first.unitized_amount
   end
 
+  it "doesn't completely wipe out the grocery list in our meal plan feature spec scenario" do
+    mealplan1.recipes << recipe7
+    mealplan1.recipes << recipe9
+    mealplan1.recipes.delete(recipe7)
+    expect(mealplan1.user.grocery_list.ingredients).to eq recipe7.ingredients.first
+  end
+
 end