fix(server): Correctly update ProductVariant tax category

server/src/api/resolvers/product.resolver.ts

@@ -117,6 +117,7 @@ export class ProductResolver {
 
     @Mutation()
     @Allow(Permission.UpdateCatalog)
+    @Decode('taxCategoryId')
     async updateProductVariants(
         @Ctx() ctx: RequestContext,
         @Args() args: UpdateProductVariantsMutationArgs,

server/src/entity/product-variant/product-variant.subscriber.ts

@@ -1,4 +1,5 @@
-import { EntitySubscriberInterface, EventSubscriber, InsertEvent } from 'typeorm';
+import { ID } from 'shared/shared-types';
+import { Connection, EntitySubscriberInterface, EventSubscriber, InsertEvent } from 'typeorm';
 
 import { I18nError } from '../../i18n/i18n-error';
 import { AdjustmentSource } from '../adjustment-source/adjustment-source.entity';
@@ -21,10 +22,7 @@ export class ProductVariantSubscriber implements EntitySubscriberInterface<Produ
         if (channelId === undefined) {
             throw new I18nError(`error.channel-id-not-set`);
         }
-        const taxCategory = await event.connection.getRepository(AdjustmentSource).findOne(taxCategoryId);
-        if (!taxCategory) {
-            throw new I18nError(`error.tax-category-not-found`, { id: taxCategoryId });
-        }
+        const taxCategory = await this.getTaxCategory(event.connection, taxCategoryId);
         const variantPrice = new ProductVariantPrice({ price, channelId });
         variantPrice.variant = event.entity;
         variantPrice.priceBeforeTax = this.getPriceBeforeTax(price, taxCategory.getTaxCategoryRate());
@@ -42,11 +40,16 @@ export class ProductVariantSubscriber implements EntitySubscriberInterface<Produ
         if (!variantPrice) {
             throw new I18nError(`error.could-not-find-product-variant-price`);
         }
+        let taxCategory = variantPrice.taxCategory;
+        if (event.queryRunner.data.taxCategoryId !== undefined) {
+            taxCategory = await this.getTaxCategory(event.connection, event.queryRunner.data.taxCategoryId);
+            variantPrice.taxCategory = taxCategory;
+        }
 
         variantPrice.price = event.entity.price || 0;
         variantPrice.priceBeforeTax = this.getPriceBeforeTax(
             variantPrice.price,
-            variantPrice.taxCategory.getTaxCategoryRate(),
+            taxCategory.getTaxCategoryRate(),
         );
         await event.manager.save(variantPrice);
     }
@@ -54,4 +57,12 @@ export class ProductVariantSubscriber implements EntitySubscriberInterface<Produ
     private getPriceBeforeTax(priceAfterTax: number, taxRatePercentage: number): number {
         return Math.round(priceAfterTax / (1 + taxRatePercentage / 100));
     }
+
+    private async getTaxCategory(connection: Connection, id: ID): Promise<AdjustmentSource> {
+        const taxCategory = await connection.getRepository(AdjustmentSource).findOne(id);
+        if (!taxCategory) {
+            throw new I18nError(`error.tax-category-not-found`, { id });
+        }
+        return taxCategory;
+    }
 }