Backport promotion code batch fix from Solidus

app/models/solidus_friendly_promotions/promotion_code/batch_builder.rb

@@ -33,7 +33,8 @@ def build_promotion_codes
       private
 
       def generate_random_codes
-        created_codes = 0
+        created_codes = promotion_code_batch.promotion_codes.count
+
         batch_size = @options[:batch_size]
 
         while created_codes < number_of_codes
@@ -42,13 +43,15 @@ def generate_random_codes
           new_codes = Array.new(max_codes_to_generate) { generate_random_code }.uniq
           codes_for_current_batch = get_unique_codes(new_codes)
 
-          codes_for_current_batch.each do |value|
-            PromotionCode.create!(
+          codes_for_current_batch = codes_for_current_batch.map do |value|
+            SolidusFriendlyPromotions::PromotionCode.create!(
               value: value,
               promotion: promotion,
               promotion_code_batch: promotion_code_batch
             )
-          end
+          rescue ActiveRecord::RecordInvalid
+            nil
+          end.compact
           created_codes += codes_for_current_batch.size
         end
       end

spec/models/solidus_friendly_promotions/promotion_code/batch_builder_spec.rb

@@ -104,4 +104,34 @@
       end
     end
   end
+
+  context "when promotion_code creation returns an error" do
+    before do
+      @raise_exception = true
+      allow(SolidusFriendlyPromotions::PromotionCode).to receive(:create!) do
+        if @raise_exception
+          @raise_exception = false
+          raise(ActiveRecord::RecordInvalid)
+        else
+          create(:friendly_promotion_code, promotion: promotion)
+        end
+      end
+    end
+
+    it "creates the correct number of codes anyway" do
+      subject.build_promotion_codes
+      expect(promotion.codes.size).to eq(number_of_codes)
+    end
+  end
+
+  context "when same promotion_codes are already present" do
+    let(:number_of_codes) { 50 }
+    before do
+      create_list(:friendly_promotion_code, 11, promotion: promotion, promotion_code_batch: code_batch)
+    end
+
+    it "creates only the missing promotion_codes" do
+      expect { subject.build_promotion_codes }.to change { promotion.codes.size }.by(39)
+    end
+  end
 end