Fix regression in item category filter

app/models/distribution.rb

@@ -48,9 +48,9 @@ class Distribution < ApplicationRecord
   enum delivery_method: { pick_up: 0, delivery: 1, shipped: 2 }
   scope :active, -> { joins(:line_items).joins(:items).where(items: { active: true }) }
   # add item_id scope to allow filtering distributions by item
-  scope :by_item_id, ->(item_id) { joins(:items).where(items: { id: item_id }) }
+  scope :by_item_id, ->(item_id) { includes(:items).where(items: { id: item_id }) }
   # partner scope to allow filtering by partner
-  scope :by_item_category_id, ->(item_category_id) { joins(:items).where(items: { item_category_id: item_category_id }) }
+  scope :by_item_category_id, ->(item_category_id) { includes(:items).where(items: { item_category_id: item_category_id }) }
   scope :by_partner, ->(partner_id) { where(partner_id: partner_id) }
   # location scope to allow filtering distributions by location
   scope :by_location, ->(storage_location_id) { where(storage_location_id: storage_location_id) }

app/services/distribution_totals_service.rb

@@ -50,7 +50,7 @@ def calculate_quantities(distributions)
   #
   # @return [Hash<Integer, Integer>]
   def calculate_values(distributions)
-    distributions
+    Distribution
       .where(id: distributions.class_filter(filter_params))
       .left_joins(line_items: [:item])
       .group("distributions.id, line_items.id, items.id")

spec/requests/distributions_requests_spec.rb

@@ -175,6 +175,18 @@
           expect(item_total_header.text).to eq("Total in #{item_category.name}")
           expect(item_value_header.text).to eq("Total Value")
         end
+
+        it "doesn't show duplicate distributions" do
+          # Add another item in given category so that a JOIN clauses would produce duplicates
+          item.update(item_category: item_category_2, value_in_cents: 50)
+
+          get distributions_path, params: params
+
+          page = Nokogiri::HTML(response.body)
+          distribution_rows = page.css("table tbody tr")
+
+          expect(distribution_rows.count).to eq(1)
+        end
       end
     end