From 4d87b88e856520d6193601f8672074f0d8a92c1a Mon Sep 17 00:00:00 2001
From: NewAlexandria <zak@newalexandria.org>
Date: Mon, 2 Mar 2026 15:23:53 -0500
Subject: [PATCH] Handle duplicate base_codes in PromotionMigrator

PromotionMigrator#copy_promotion_codes joined legacy and new
promotion_code_batches on base_code alone, which is not unique across
promotions; unrelated batches sharing a base_code multiplied rows in the
INSERT ... SELECT and triggered PG::UniqueViolation on
index_solidus_promotions_promotion_codes_on_value. Constrain the join on
promotion_id and created_at so each legacy code resolves to the correct
new batch for the promotion being migrated.
---
 .../solidus_promotions/promotion_migrator.rb  |  5 +-
 .../promotion_migrator_spec.rb                | 49 +++++++++++++++++++
 2 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/promotions/lib/solidus_promotions/promotion_migrator.rb b/promotions/lib/solidus_promotions/promotion_migrator.rb
index b7b22c691b0..f3e9313aa54 100644
--- a/promotions/lib/solidus_promotions/promotion_migrator.rb
+++ b/promotions/lib/solidus_promotions/promotion_migrator.rb
@@ -61,7 +61,10 @@ def copy_promotion_codes(new_promotion)
         SELECT solidus_promotions_promotions.id AS promotion_id, solidus_promotions_promotion_code_batches.id AS promotion_code_batch_id, value, spree_promotion_codes.created_at, spree_promotion_codes.updated_at
         FROM spree_promotion_codes
         LEFT OUTER JOIN spree_promotion_code_batches ON spree_promotion_code_batches.id = spree_promotion_codes.promotion_code_batch_id
-        LEFT OUTER JOIN solidus_promotions_promotion_code_batches ON solidus_promotions_promotion_code_batches.base_code = spree_promotion_code_batches.base_code
+        LEFT OUTER JOIN solidus_promotions_promotion_code_batches
+          ON solidus_promotions_promotion_code_batches.base_code = spree_promotion_code_batches.base_code
+          AND solidus_promotions_promotion_code_batches.promotion_id = #{new_promotion.id}
+          AND solidus_promotions_promotion_code_batches.created_at = spree_promotion_code_batches.created_at
         INNER JOIN spree_promotions ON spree_promotion_codes.promotion_id = spree_promotions.id
         INNER JOIN solidus_promotions_promotions ON spree_promotions.id = solidus_promotions_promotions.original_promotion_id
         WHERE spree_promotion_codes.promotion_id = #{new_promotion.original_promotion_id};
diff --git a/promotions/spec/lib/solidus_promotions/promotion_migrator_spec.rb b/promotions/spec/lib/solidus_promotions/promotion_migrator_spec.rb
index 85b9a8e5cb6..031586030ac 100644
--- a/promotions/spec/lib/solidus_promotions/promotion_migrator_spec.rb
+++ b/promotions/spec/lib/solidus_promotions/promotion_migrator_spec.rb
@@ -52,6 +52,55 @@
     end
   end
 
+  context "when multiple promotions have batches with the same base_code" do
+    let(:shared_base_code) { "SUVIE" }
+    let(:shared_time) { Time.current.change(usec: 0) }
+    let!(:spree_promotion) { create(:promotion) }
+    let!(:another_spree_promotion) { create(:promotion) }
+    let!(:first_batch) do
+      Spree::PromotionCodeBatch.create!(
+        promotion: spree_promotion,
+        base_code: shared_base_code,
+        number_of_codes: 1,
+        created_at: shared_time,
+        updated_at: shared_time
+      )
+    end
+    let!(:second_batch) do
+      Spree::PromotionCodeBatch.create!(
+        promotion: another_spree_promotion,
+        base_code: shared_base_code,
+        number_of_codes: 1,
+        created_at: shared_time,
+        updated_at: shared_time
+      )
+    end
+    let!(:first_code) do
+      create(
+        :promotion_code,
+        promotion: spree_promotion,
+        promotion_code_batch: first_batch,
+        value: "suvie-lgm4gw"
+      )
+    end
+    let!(:second_code) do
+      create(
+        :promotion_code,
+        promotion: another_spree_promotion,
+        promotion_code_batch: second_batch,
+        value: "suvie-abc123"
+      )
+    end
+
+    it "copies each code exactly once without raising a duplicate value error" do
+      expect { subject }.not_to raise_error
+      expect(SolidusPromotions::PromotionCode.where(value: [first_code.value, second_code.value]).count).to eq(2)
+      expect(
+        SolidusPromotions::PromotionCode.where(value: [first_code.value, second_code.value]).group(:value).count.values
+      ).to all(eq(1))
+    end
+  end
+
   context "if our rules and actions are missing from the promotion map" do
     let(:promotion_map) do
       {