Extract tag_rule filtering into separate service

app/services/order_cycle_distributed_products.rb

@@ -36,74 +36,7 @@ class OrderCycleDistributedProducts
       joins(:stock_items).
       where(query_stock_with_overrides)
 
-    if distributor_rules.any?
-      stocked_variants = apply_tag_rules(stocked_variants)
-    end
-
-    stocked_variants
-  end
-
-  def apply_tag_rules(stocked_variants)
-    stocked_variants.where(query_with_tag_rules)
-  end
-
-  def distributor_rules
-    @distributor_rules ||= TagRule::FilterProducts.prioritised.for(distributor)
-  end
-
-  def customer_tag_list
-    customer.andand.tag_list || []
-  end
-
-  def default_rule_tags
-    default_rules.map(&:preferred_variant_tags)
-  end
-
-  def hide_rule_tags
-    hide_rules.map(&:preferred_variant_tags)
-  end
-
-  def show_rule_tags
-    show_rules.map(&:preferred_variant_tags)
-  end
-
-  def overrides_to_hide
-    @overrides_to_hide = VariantOverride.where(hub_id: distributor.id).
-      tagged_with(default_rule_tags + hide_rule_tags, any: true).
-      pluck(:id)
-  end
-
-  def overrides_to_show
-    @overrides_to_show = VariantOverride.where(hub_id: distributor.id).
-      tagged_with(show_rule_tags, any: true).
-      pluck(:id)
-  end
-
-  def customer_applicable_rules
-    # Rules which apply specifically to the current customer
-    @customer_applicable_rules ||= non_default_rules.select{ |rule| customer_tagged?(rule) }
-  end
-
-  def default_rules
-    # These rules hide a variant_override with tag X
-    distributor_rules.select(&:is_default?)
-  end
-
-  def non_default_rules
-    # These rules show or hide a variant_override with tag X for customer with tag Y
-    distributor_rules.reject(&:is_default?)
-  end
-
-  def hide_rules
-    @hide_rules ||= customer_applicable_rules.select{ |rule| rule.preferred_matched_variants_visibility == 'hidden'}
-  end
-
-  def show_rules
-    customer_applicable_rules - hide_rules
-  end
-
-  def customer_tagged?(rule)
-    customer_tag_list.include? rule.preferred_customer_tags
+    ProductTagRulesFilterer.new(distributor, customer, stocked_variants).call
   end
 
   def query_stock_with_overrides
@@ -114,22 +47,6 @@ class OrderCycleDistributedProducts
                                       AND #{variant_not_on_demand} AND #{variant_in_stock} ) )"
   end
 
-  def query_with_tag_rules
-    "#{variant_not_overriden} OR ( #{variant_overriden}
-                                   AND ( #{override_not_hidden_by_rule}
-                                   OR #{override_shown_by_rule} ) )"
-  end
-
-  def override_not_hidden_by_rule
-    return "FALSE" unless overrides_to_hide.any?
-    "variant_overrides.id NOT IN (#{overrides_to_hide.join(',')})"
-  end
-
-  def override_shown_by_rule
-    return "FALSE" unless overrides_to_show.any?
-    "variant_overrides.id IN (#{overrides_to_show.join(',')})"
-  end
-
   def variant_not_overriden
     "variant_overrides.id IS NULL"
   end

app/services/product_tag_rules_filterer.rb

@@ -0,0 +1,111 @@
+# Takes a Spree::Variant AR object and filters results based on applicable tag rules.
+# Tag rules exists in the context of enterprise, customer, and variant_overrides,
+# and are applied to variant_overrides only. Returns a Spree::Variant AR object.
+
+class ProductTagRulesFilterer
+  def initialize(distributor, customer, variants_relation)
+    @distributor = distributor
+    @customer = customer
+    @variants_relation = variants_relation
+  end
+
+  def call
+    return variants_relation unless distributor_rules.any?
+
+    filter(variants_relation)
+  end
+
+  private
+
+  attr_accessor :distributor, :customer, :variants_relation
+
+  def distributor_rules
+    @distributor_rules ||= TagRule::FilterProducts.prioritised.for(distributor).all
+  end
+
+  def filter(variants_relation)
+    return variants_relation unless overrides_to_hide.any?
+
+    variants_relation.where(query_with_tag_rules)
+  end
+
+  def query_with_tag_rules
+    "#{variant_not_overriden} OR ( #{variant_overriden}
+                                   AND ( #{override_not_hidden_by_rule}
+                                   OR #{override_shown_by_rule} ) )"
+  end
+
+  def variant_not_overriden
+    "variant_overrides.id IS NULL"
+  end
+
+  def variant_overriden
+    "variant_overrides.id IS NOT NULL"
+  end
+
+  def override_not_hidden_by_rule
+    return "FALSE" unless overrides_to_hide.any?
+    "variant_overrides.id NOT IN (#{overrides_to_hide.join(',')})"
+  end
+
+  def override_shown_by_rule
+    return "FALSE" unless overrides_to_show.any?
+    "variant_overrides.id IN (#{overrides_to_show.join(',')})"
+  end
+
+  def overrides_to_hide
+    @overrides_to_hide ||= VariantOverride.where(hub_id: distributor.id).
+      tagged_with(default_rule_tags + hide_rule_tags, any: true).
+      pluck(:id)
+  end
+
+  def overrides_to_show
+    @overrides_to_show ||= VariantOverride.where(hub_id: distributor.id).
+      tagged_with(show_rule_tags, any: true).
+      pluck(:id)
+  end
+
+  def default_rule_tags
+    default_rules.map(&:preferred_variant_tags)
+  end
+
+  def hide_rule_tags
+    hide_rules.map(&:preferred_variant_tags)
+  end
+
+  def show_rule_tags
+    show_rules.map(&:preferred_variant_tags)
+  end
+
+  def default_rules
+    # These rules hide a variant_override with tag X and apply to all customers
+    distributor_rules.select(&:is_default?)
+  end
+
+  def non_default_rules
+    # These rules show or hide a variant_override with tag X for customer with tag Y
+    distributor_rules.reject(&:is_default?)
+  end
+
+  def customer_applicable_rules
+    # Rules which apply specifically to the current customer
+    @customer_applicable_rules ||= non_default_rules.select{ |rule| customer_tagged?(rule) }
+  end
+
+  def hide_rules
+    @hide_rules ||= customer_applicable_rules.
+      select{ |rule| rule.preferred_matched_variants_visibility == 'hidden' }
+  end
+
+  def show_rules
+    customer_applicable_rules - hide_rules
+  end
+
+  def customer_tagged?(rule)
+    customer_tag_list.include? rule.preferred_customer_tags
+  end
+
+  def customer_tag_list
+    customer.andand.tag_list || []
+  end
+end

spec/services/product_tag_rules_filterer_spec.rb

@@ -0,0 +1,98 @@
+require "spec_helper"
+
+describe ProductTagRulesFilterer do
+  describe "filtering by tag rules" do
+    let!(:distributor) { create(:distributor_enterprise) }
+    let(:product) { create(:product, supplier: distributor) }
+    let(:v1) { create(:variant, product: product) }
+    let(:v2) { create(:variant, product: product) }
+    let(:v3) { create(:variant, product: product) }
+    let(:v4) { create(:variant, product: product) }
+    let(:variant_hidden_by_default) { create(:variant_override, variant: v1, hub: distributor) }
+    let(:variant_hidden_by_rule) { create(:variant_override, variant: v2, hub: distributor) }
+    let(:variant_shown_by_rule) { create(:variant_override, variant: v3, hub: distributor) }
+    let(:variant_hidden_for_another_customer) { create(:variant_override, variant: v4, hub: distributor) }
+    let(:customer) { create(:customer, enterprise: distributor) }
+    let(:variants_relation) {
+      Spree::Variant.joins(:product).where("spree_products.supplier_id = ?", distributor.id)
+    }
+    let(:default_hide_rule) {
+      create(:filter_products_tag_rule,
+             enterprise: distributor,
+             is_default: true,
+             preferred_variant_tags: "hide_these_variants_from_everyone",
+             preferred_matched_variants_visibility: "hidden")
+    }
+    let!(:hide_rule) {
+      create(:filter_products_tag_rule,
+             enterprise: distributor,
+             preferred_variant_tags: "hide_these_variants",
+             preferred_customer_tags: "hide_from_these_customers",
+             preferred_matched_variants_visibility: "hidden" )
+    }
+    let!(:show_rule) {
+      create(:filter_products_tag_rule,
+             enterprise: distributor,
+             preferred_variant_tags: "show_these_variants",
+             preferred_customer_tags: "show_for_these_customers",
+             preferred_matched_variants_visibility: "visible" )
+    }
+    let!(:non_applicable_rule) {
+      create(:filter_products_tag_rule,
+             enterprise: distributor,
+             preferred_variant_tags: "hide_these_other_variants",
+             preferred_customer_tags: "hide_from_other_customers",
+             preferred_matched_variants_visibility: "hidden" )
+    }
+    let(:filterer) { described_class.new(distributor, customer, variants_relation) }
+
+    context "when the distributor has no rules" do
+      it "returns the relation unchanged" do
+        expect(filterer.call).to eq variants_relation
+      end
+    end
+
+    describe "#customer_applicable_rules" do
+      it "returns a list of tags that apply to the current customer" do
+        customer.update_attribute(:tag_list, show_rule.preferred_customer_tags)
+
+        customer_applicable_rules = filterer.__send__(:customer_applicable_rules)
+        expect(customer_applicable_rules).to eq [show_rule]
+      end
+    end
+
+    describe "#overrides_to_hide" do
+      context "with default rules" do
+        it "lists overrides tagged as hidden for this customer" do
+          variant_hidden_by_default.update_attribute(:tag_list, default_hide_rule.preferred_variant_tags)
+
+          overrides_to_hide = filterer.__send__(:overrides_to_hide)
+          expect(overrides_to_hide).to eq [variant_hidden_by_default.id]
+        end
+      end
+
+      context "with default and specific rules" do
+        it "lists overrides tagged as hidden for this customer" do
+          customer.update_attribute(:tag_list, hide_rule.preferred_customer_tags)
+          variant_hidden_by_default.update_attribute(:tag_list, default_hide_rule.preferred_variant_tags)
+          variant_hidden_by_rule.update_attribute(:tag_list, hide_rule.preferred_variant_tags)
+          variant_hidden_for_another_customer.update_attribute(:tag_list, non_applicable_rule.preferred_variant_tags)
+
+          overrides_to_hide = filterer.__send__(:overrides_to_hide)
+          expect(overrides_to_hide).to eq [variant_hidden_by_default.id, variant_hidden_by_rule.id]
+        end
+      end
+
+    end
+
+    describe "#overrides_to_show" do
+      it "lists overrides tagged as visible for this customer" do
+        customer.update_attribute(:tag_list, show_rule.preferred_customer_tags)
+        variant_shown_by_rule.update_attribute(:tag_list, show_rule.preferred_variant_tags)
+
+        overrides_to_show = filterer.__send__(:overrides_to_show)
+        expect(overrides_to_show).to eq [variant_shown_by_rule.id]
+      end
+    end
+  end
+end