DEVX-640: refactoring resolveKey and fixing empty set attribute

Author: ShipilA

commercetools/commercetools-importapi-utils/src/main/java/com/commercetools/sdk/ProductUtil.java

@@ -35,11 +35,7 @@
 import io.vrap.rmf.base.client.Builder;
 
 public final class ProductUtil {
-    private static KeyResolverService keyResolverService;
-
-    public ProductUtil() {
-        keyResolverService = new ExpandObjResolverService();
-    }
+    private static KeyResolverService keyResolverService= new ExpandObjResolverService();
 
     public static ProductDraftImport toProductDraftImport(ProductProjection product) {
         var draft = ProductDraftImport.builder()
@@ -229,7 +225,7 @@ private static Attribute mapAttribute(com.commercetools.api.models.product.Attri
         if (value instanceof ArrayList) {
             var list = (ArrayList<?>) value;
             if (list.isEmpty()) {
-                return Attribute.referenceSetBuilder().build();
+                return Attribute.textSetBuilder().value().build();
             }
             if (list.get(0) instanceof LocalDate) {
                 return Attribute.dateSetBuilder().name(attribute.getName()).value((ArrayList<LocalDate>) list).build();

commercetools/commercetools-importapi-utils/src/test/java/com/commercetools/sdk/ProductUtilTest.java

@@ -188,7 +188,7 @@ void productTransformTestAttributesEmptySet() {
         var transformedProduct = toProductDraftImport(testProduct);
         assertEquals(testProduct.getKey(), transformedProduct.getKey());
         assertEquals(1, transformedProduct.getAttributes().size());
-        assertEquals("reference", transformedProduct.getAttributes().get(0).getType());
+        assertEquals("text-set", transformedProduct.getAttributes().get(0).getType());
     }
 
     @Test