fix(#4297): flaky report spec

Changes the test to explicitly create all the items needed. This removes
flakiness surrounding potential situations where generated items get
counted as disposable.

spec/services/reports/children_served_report_service_spec.rb

@@ -106,35 +106,55 @@
     end
   end
   describe "#disposable_diapers_from_kits_total" do
-    it "calculates the number of disposable diapers that have been distributed within kits" do
+    it "calculates the number of disposable diapers that have been distributed within kits this year" do
       organization = create(:organization, skip_items: true)
-      toddler_disposable_kit = create(:kit, :with_item, organization: organization)
-      infant_disposable_kit = create(:kit, :with_item, organization: organization)
-      infant_cloth_kit = create(:kit, :with_item, organization: organization)
-
-      within_time = Time.zone.parse("2020-05-31 14:00:00")
 
+      # create disposable/ nondisposable base items
       create(:base_item, name: "Toddler Disposable Diaper", partner_key: "toddler diapers", category: "disposable diaper")
       create(:base_item, name: "Infant Disposable Diaper", partner_key: "infant diapers", category: "infant disposable diaper")
       create(:base_item, name: "Infant Cloth Diaper", partner_key: "infant cloth diapers", category: "cloth diaper")
 
-      toddler_disposable_kit_item = create(:item, name: "Toddler Disposable Diapers", partner_key: "toddler diapers")
-      infant_disposable_kit_item = create(:item, name: "Infant Disposable Diapers", partner_key: "infant diapers")
-      infant_cloth_kit_item = create(:item, name: "Infant Cloth Diapers", partner_key: "infant cloth diapers")
+      # create disposable/ nondisposable items
+      toddler_disposable_kit_item = create(:item, name: "Toddler Disposable Diaper", partner_key: "toddler diapers", organization: organization)
+      infant_disposable_kit_item = create(:item, name: "Infant Disposable Diapers", partner_key: "infant diapers", organization: organization)
+      infant_cloth_kit_item = create(:item, name: "Infant Cloth Diapers", partner_key: "infant cloth diapers", organization: organization)
+
+      # create line items that contain the d/nd items
+      toddler_disposable_line_item = create(:line_item, item: toddler_disposable_kit_item, quantity: 5)
+      infant_disposable_line_item = create(:line_item, item: infant_disposable_kit_item, quantity: 5)
+      infant_cloth_line_item = create(:line_item, item: infant_cloth_kit_item, quantity: 5)
 
-      toddler_disposable_kit.line_items.first.update!(item_id: toddler_disposable_kit_item.id, quantity: 5)
-      infant_disposable_kit.line_items.first.update!(item_id: infant_disposable_kit_item.id, quantity: 5)
-      infant_cloth_kit.line_items.first.update!(item_id: infant_cloth_kit_item.id, quantity: 5)
+      # create kits that contain the d/nd line items
+      toddler_disposable_kit = create(:kit, organization: organization, line_items: [toddler_disposable_line_item])
+      infant_disposable_kit = create(:kit, organization: organization, line_items: [infant_disposable_line_item])
+      infant_cloth_kit = create(:kit, organization: organization, line_items: [infant_cloth_line_item])
+
+      # create items which have the kits
+      create(:base_item, name: "Unrelated Base", partner_key: "unrelated base", category: "unrelated base")
+      infant_disposable_dist_item = create(:item, name: "Dist Item 1", organization: organization, partner_key: "unrelated base", kit: toddler_disposable_kit)
+      toddler_disposable_dist_item = create(:item, name: "Dist Item 2", organization: organization, partner_key: "unrelated base", kit: infant_disposable_kit)
+      infant_cloth_dist_item = create(:item, name: "Dist Item 3", organization: organization, partner_key: "unrelated base", kit: infant_cloth_kit)
+
+      within_time = Time.zone.parse("2020-05-31 14:00:00")
 
+      # create empty distributions
       infant_distribution = create(:distribution, organization: organization, issued_at: within_time)
       toddler_distribution = create(:distribution, organization: organization, issued_at: within_time)
 
-      create(:line_item, quantity: 10, item: toddler_disposable_kit.item, itemizable: toddler_distribution)
-      create(:line_item, quantity: 10, item: infant_disposable_kit.item, itemizable: infant_distribution)
-      create(:line_item, :distribution, quantity: 10, item: infant_cloth_kit.item, itemizable: infant_distribution)
+      # add line items to distributions which contain the d/nd kits
+      create(:line_item, quantity: 10, item: toddler_disposable_dist_item, itemizable: toddler_distribution)
+      create(:line_item, quantity: 10, item: infant_disposable_dist_item, itemizable: infant_distribution)
+      create(:line_item, :distribution, quantity: 10, item: infant_cloth_dist_item, itemizable: infant_distribution)
 
       service = described_class.new(organization: organization, year: within_time.year)
 
+      # Find distributions, that has a
+      # Line item, that has an
+      # Item, which has a
+      # Kit, which has a
+      # Line item, which has an
+      # Item, which is a disposable diaper.
+      # And then add all those quantities up
       expect(service.disposable_diapers_from_kits_total).to eq(100)
     end
   end