feat(F-091): completed feature

project/src/modules/catalog/domain/errors.ts

@@ -19,9 +19,11 @@ export class ProductBrandNotFoundError extends Error {
   }
 }
 
+export type ProductVariantCode = 'sku' | 'ean';
+
 export class ProductVariantCodeAlreadyExistsError extends Error {
-  constructor() {
-    super('Product variant SKU or EAN already exists');
+  constructor(public readonly field?: ProductVariantCode) {
+    super(field ? `Product variant ${field.toUpperCase()} already exists` : 'Product variant SKU or EAN already exists');
     this.name = 'ProductVariantCodeAlreadyExistsError';
   }
 }

project/src/modules/catalog/infrastructure/pg-variant-repository.ts

@@ -1,5 +1,8 @@
 import type pg from 'pg';
-import { ProductVariantCodeAlreadyExistsError } from '../domain/errors.js';
+import {
+  ProductVariantCodeAlreadyExistsError,
+  type ProductVariantCode,
+} from '../domain/errors.js';
 import type { ProductVariantRepository } from '../domain/ports.js';
 import type { NewProductVariant, ProductVariant, ProductVariantPatch } from '../domain/variant.js';
 
@@ -47,7 +50,7 @@ export class PgProductVariantRepository implements ProductVariantRepository {
       return toVariant(row);
     } catch (error) {
       if (isPgError(error, UNIQUE_VIOLATION)) {
-        throw new ProductVariantCodeAlreadyExistsError();
+        throw new ProductVariantCodeAlreadyExistsError(uniqueConstraintField(error));
       }
       throw error;
     }
@@ -82,7 +85,7 @@ export class PgProductVariantRepository implements ProductVariantRepository {
       return row ? toVariant(row) : undefined;
     } catch (error) {
       if (isPgError(error, UNIQUE_VIOLATION)) {
-        throw new ProductVariantCodeAlreadyExistsError();
+        throw new ProductVariantCodeAlreadyExistsError(uniqueConstraintField(error));
       }
       throw error;
     }
@@ -116,3 +119,14 @@ function toVariant(row: VariantRow): ProductVariant {
 function isPgError(error: unknown, code: string): boolean {
   return typeof error === 'object' && error !== null && 'code' in error && error.code === code;
 }
+
+function uniqueConstraintField(error: unknown): ProductVariantCode | undefined {
+  if (typeof error !== 'object' || error === null || !('constraint' in error)) {
+    return undefined;
+  }
+  const constraint = error.constraint;
+  if (typeof constraint !== 'string') return undefined;
+  if (constraint.endsWith('_sku_key')) return 'sku';
+  if (constraint.endsWith('_ean_key')) return 'ean';
+  return undefined;
+}