fix(billing): display product fee filters

app/models/fee.rb

@@ -153,6 +153,7 @@ def item_description
   def invoice_name
     return invoice_display_name if invoice_display_name.present?
     return charge.invoice_display_name.presence || billable_metric.name if charge?
+    return invoiceable.invoice_name if product?
     return add_on.invoice_name if add_on?
     return invoiceable&.name.presence || fee_type if credit?
     return fixed_charge.invoice_display_name.presence || fixed_charge_add_on.invoice_name if fixed_charge?
@@ -161,7 +162,11 @@ def invoice_name
   end
 
   def filter_display_name(separator: ", ")
-    charge_filter&.display_name(separator:)
+    if product?
+      product_filter&.invoice_name
+    else
+      charge_filter&.display_name(separator:)
+    end
   end
 
   def grouped_by_display
@@ -173,7 +178,7 @@ def grouped_by_display
   def invoice_sorting_clause
     base_clause = "#{invoice_name} #{filter_display_name}".downcase
 
-    return base_clause unless charge?
+    return base_clause unless charge? || product?
     return base_clause if grouped_by.blank?
 
     "#{invoice_name} #{grouped_by.values.join} #{filter_display_name}".downcase
@@ -184,11 +189,15 @@ def currency
   end
 
   def grouped_or_filtered?
-    grouped_by.present? || charge_filter_id.present?
+    grouped_by.present? || filtered?
   end
 
   def ungrouped_or_filtered?
-    grouped_by.blank? || charge_filter_id.present?
+    grouped_by.blank? || filtered?
+  end
+
+  def filtered?
+    charge_filter_id.present? || product_filter_id.present?
   end
 
   def presentation_group_keys_values_displayed_in_invoice

app/views/helpers/fee_display_helper.rb

@@ -6,7 +6,13 @@ def self.grouped_by_display(fee)
   end
 
   def self.fee_title(fee)
-    fee.invoice_name + grouped_by_display(fee) + (fee.charge_filter_id? ? " • #{fee.filter_display_name(separator: " • ")}" : "")
+    filter_display = if fee.filtered?
+      " • #{fee.filter_display_name(separator: " • ")}"
+    else
+      ""
+    end
+
+    fee.invoice_name + grouped_by_display(fee) + filter_display
   end
 
   def self.should_display_subscription_fee?(invoice_subscription)

spec/models/fee_spec.rb

@@ -600,6 +600,48 @@
     end
   end
 
+  describe "#filter_display_name" do
+    let(:charge) { create(:standard_charge) }
+    let(:charge_filter) { create(:charge_filter, charge:, invoice_display_name: "EU Premium") }
+    let(:product) { create(:product) }
+    let(:product_filter) { create(:product_filter, product:, invoice_display_name: "EU Premium") }
+
+    context "when the fee is charge-backed" do
+      let(:fee) { build(:charge_fee, charge:, charge_filter:) }
+
+      it "uses the charge filter display name" do
+        expect(fee.filter_display_name).to eq("EU Premium")
+      end
+    end
+
+    context "when the fee is product-backed" do
+      let(:fee) { build(:fee, fee_type: :product, product_filter:) }
+
+      it "uses the product filter invoice name" do
+        expect(fee.filter_display_name).to eq("EU Premium")
+      end
+
+      context "when sorting the invoice fees" do
+        let(:product) { create(:product, name: "Compute") }
+        let(:fee) do
+          build(
+            :fee,
+            fee_type: :product,
+            product_filter:,
+            invoiceable: product,
+            subscription: nil,
+            invoice_display_name: nil,
+            grouped_by: {}
+          )
+        end
+
+        it "includes the product filter" do
+          expect(fee.invoice_sorting_clause).to eq("compute eu premium")
+        end
+      end
+    end
+  end
+
   describe "#grouped_by_display" do
     let(:charge) { create(:standard_charge, properties:) }
     let(:fee) { described_class.new(charge:, fee_type: "charge", grouped_by:) }
@@ -977,6 +1019,11 @@
       fee = build(:charge_fee, grouped_by: {}, charge_filter_id: SecureRandom.uuid)
       expect(fee).to be_grouped_or_filtered
     end
+
+    it "returns true when product_filter_id is present" do
+      fee = build(:fee, fee_type: :product, grouped_by: {}, product_filter_id: SecureRandom.uuid)
+      expect(fee).to be_grouped_or_filtered
+    end
   end
 
   describe "#ungrouped_or_filtered?" do
@@ -994,6 +1041,35 @@
       fee = build(:charge_fee, grouped_by: {"cloud" => "aws"}, charge_filter_id: SecureRandom.uuid)
       expect(fee).to be_ungrouped_or_filtered
     end
+
+    it "returns true when product_filter_id is present" do
+      fee = build(:fee, fee_type: :product, grouped_by: {"cloud" => "aws"}, product_filter_id: SecureRandom.uuid)
+      expect(fee).to be_ungrouped_or_filtered
+    end
+  end
+
+  describe "#filtered?" do
+    let(:fee) { build(:fee) }
+
+    it "returns false when neither filter is present" do
+      expect(fee).not_to be_filtered
+    end
+
+    context "when the charge filter is present" do
+      let(:fee) { build(:charge_fee, charge_filter_id: SecureRandom.uuid) }
+
+      it "returns true" do
+        expect(fee).to be_filtered
+      end
+    end
+
+    context "when the product filter is present" do
+      let(:fee) { build(:fee, fee_type: :product, product_filter_id: SecureRandom.uuid) }
+
+      it "returns true" do
+        expect(fee).to be_filtered
+      end
+    end
   end
 
   describe "#basic_rate_percentage?" do

spec/views/helpers/fee_display_helper_spec.rb

@@ -43,6 +43,27 @@
         expect(subject).to eq("Compute • eu • EU Premium")
       end
     end
+
+    context "when product filter is present" do
+      let(:product) { create(:product, organization: charge.organization, name: "Compute") }
+      let(:product_filter) { create(:product_filter, product:, invoice_display_name: "EU Premium") }
+      let(:fee) do
+        build(
+          :fee,
+          charge: nil,
+          fee_type: "product",
+          invoiceable: product,
+          subscription: nil,
+          product_filter:,
+          grouped_by: {},
+          invoice_display_name: nil
+        )
+      end
+
+      it "returns invoice_name appended with the product filter display name" do
+        expect(subject).to eq("Compute • EU Premium")
+      end
+    end
   end
 
   describe ".should_display_subscription_fee?" do