ENGCOM-5436: #758: applied_taxes of empty cart causes 'Internal server error' message on PHP 7.2 #759

Author: naydav

app/code/Magento/QuoteGraphQl/Model/Resolver/CartPrices.php

@@ -73,7 +73,7 @@ private function getAppliedTaxes(Total $total, string $currency): array
         $appliedTaxesData = [];
         $appliedTaxes = $total->getAppliedTaxes();
 
-        if (count($appliedTaxes) === 0) {
+        if (empty($appliedTaxes)) {
             return $appliedTaxesData;
         }
 

dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Customer/CartTotalsTest.php

@@ -64,6 +64,33 @@ public function testGetCartTotalsWithTaxApplied()
         self::assertEquals('USD', $appliedTaxesResponse[0]['amount']['currency']);
     }
 
+    /**
+     * @magentoApiDataFixture Magento/Customer/_files/customer.php
+     * @magentoApiDataFixture Magento/GraphQl/Tax/_files/tax_rule_for_region_1.php
+     * @magentoApiDataFixture Magento/GraphQl/Catalog/_files/simple_product.php
+     * @magentoApiDataFixture Magento/GraphQl/Catalog/_files/apply_tax_for_simple_product.php
+     * @magentoApiDataFixture Magento/GraphQl/Quote/_files/customer/create_empty_cart.php
+     * @magentoApiDataFixture Magento/GraphQl/Quote/_files/set_new_shipping_address.php
+     * @magentoApiDataFixture Magento/GraphQl/Quote/_files/set_new_billing_address.php
+     */
+    public function testGetCartTotalsWithEmptyCart()
+    {
+        $maskedQuoteId = $this->getMaskedQuoteIdByReservedOrderId->execute('test_quote');
+        $query = $this->getQuery($maskedQuoteId);
+        $response = $this->graphQlQuery($query, [], '', $this->getHeaderMap());
+
+        self::assertArrayHasKey('prices', $response['cart']);
+        $pricesResponse = $response['cart']['prices'];
+        self::assertEquals(0, $pricesResponse['grand_total']['value']);
+        self::assertEquals(0, $pricesResponse['subtotal_including_tax']['value']);
+        self::assertEquals(0, $pricesResponse['subtotal_excluding_tax']['value']);
+        self::assertEquals(0, $pricesResponse['subtotal_with_discount_excluding_tax']['value']);
+
+        $appliedTaxesResponse = $pricesResponse['applied_taxes'];
+
+        self::assertCount(0, $appliedTaxesResponse);
+    }
+
     /**
      * @magentoApiDataFixture Magento/Customer/_files/customer.php
      * @magentoApiDataFixture Magento/GraphQl/Catalog/_files/simple_product.php

dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Guest/CartTotalsTest.php

@@ -59,6 +59,32 @@ public function testGetCartTotalsWithTaxApplied()
         self::assertEquals('USD', $appliedTaxesResponse[0]['amount']['currency']);
     }
 
+    /**
+     * @magentoApiDataFixture Magento/GraphQl/Tax/_files/tax_rule_for_region_1.php
+     * @magentoApiDataFixture Magento/GraphQl/Catalog/_files/simple_product.php
+     * @magentoApiDataFixture Magento/GraphQl/Catalog/_files/apply_tax_for_simple_product.php
+     * @magentoApiDataFixture Magento/GraphQl/Quote/_files/guest/create_empty_cart.php
+     * @magentoApiDataFixture Magento/GraphQl/Quote/_files/set_new_shipping_address.php
+     * @magentoApiDataFixture Magento/GraphQl/Quote/_files/set_new_billing_address.php
+     */
+    public function testGetCartTotalsWithEmptyCart()
+    {
+        $maskedQuoteId = $this->getMaskedQuoteIdByReservedOrderId->execute('test_quote');
+        $query = $this->getQuery($maskedQuoteId);
+        $response = $this->graphQlQuery($query);
+
+        self::assertArrayHasKey('prices', $response['cart']);
+        $pricesResponse = $response['cart']['prices'];
+        self::assertEquals(0, $pricesResponse['grand_total']['value']);
+        self::assertEquals(0, $pricesResponse['subtotal_including_tax']['value']);
+        self::assertEquals(0, $pricesResponse['subtotal_excluding_tax']['value']);
+        self::assertEquals(0, $pricesResponse['subtotal_with_discount_excluding_tax']['value']);
+
+        $appliedTaxesResponse = $pricesResponse['applied_taxes'];
+
+        self::assertCount(0, $appliedTaxesResponse);
+    }
+
     /**
      * @magentoApiDataFixture Magento/GraphQl/Catalog/_files/simple_product.php
      * @magentoApiDataFixture Magento/GraphQl/Quote/_files/guest/create_empty_cart.php