Create variant appends variant in rankings

packages/medusa/src/services/__tests__/product-variant.js

@@ -148,7 +148,7 @@ describe("ProductVariantService", () => {
       expect(productVariantRepository.create).toHaveBeenCalledWith({
         id: IdMap.getId("v2"),
         product_id: IdMap.getId("ironman"),
-        variant_rank: 0,
+        variant_rank: 1,
         options: [
           {
             id: IdMap.getId("test"),

packages/medusa/src/services/product-variant.js

@@ -174,7 +174,7 @@ class ProductVariantService extends BaseService {
         )
       }
 
-      if (!rest.variant_rank) rest.variant_rank = 0
+      if (!rest.variant_rank) rest.variant_rank = product.variants.length
 
       const toCreate = {
         ...rest,