MC-19226: Cart Promotions :: Store promotions detail on the quote

- review fixes

Author: Prabhu Ram

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

@@ -42,7 +42,7 @@ private function getDiscountValues(Quote $quote)
         $discountValues=[];
         $address = $quote->getShippingAddress();
         $totalDiscounts = $address->getExtensionAttributes()->getDiscounts();
-        if ($totalDiscounts) {
+        if ($totalDiscounts && is_array($totalDiscounts)) {
             foreach ($totalDiscounts as $value) {
                 $discount = [];
                 $amount = [];

app/code/Magento/SalesRule/Model/Data/RuleDiscount.php

@@ -9,11 +9,12 @@
 
 use Magento\Framework\Api\ExtensionAttributesInterface;
 use Magento\SalesRule\Api\Data\RuleDiscountInterface;
+use Magento\Framework\Api\AbstractExtensibleObject;
 
 /**
  * Data Model for Rule Discount
  */
-class RuleDiscount extends \Magento\Framework\Api\AbstractExtensibleObject implements RuleDiscountInterface
+class RuleDiscount extends AbstractExtensibleObject implements RuleDiscountInterface
 {
     const KEY_DISCOUNT_DATA = 'discount';
     const KEY_RULE_LABEL = 'rule';

dev/tests/integration/testsuite/Magento/SalesRule/Model/Rule/Action/Discount/CartFixedTest.php

@@ -164,6 +164,7 @@ public function testDiscountsOnQuoteWithFixedDiscount(): void
         /** @var CartItemInterface $item */
         $item = $quote->getItems()[0];
         $quoteItemDiscounts = $item->getExtensionAttributes()->getDiscounts();
+        $this->assertArrayHasKey('0', $quoteItemDiscounts);
         $discountData = $quoteItemDiscounts[0]->getDiscountData();
         $ruleLabel = $quoteItemDiscounts[0]->getRuleLabel();
         $this->assertEquals(5, $discountData->getAmount());
@@ -173,6 +174,7 @@ public function testDiscountsOnQuoteWithFixedDiscount(): void
         $this->assertEquals('TestRule_Coupon', $ruleLabel);
 
         $quoteAddressItemDiscount = $quote->getShippingAddressesItems()[0]->getExtensionAttributes()->getDiscounts();
+        $this->assertArrayHasKey('0', $quoteAddressItemDiscount);
         $discountData = $quoteAddressItemDiscount[0]->getDiscountData();
         $ruleLabel = $quoteAddressItemDiscount[0]->getRuleLabel();
         $this->assertEquals(5, $discountData->getAmount());

dev/tests/integration/testsuite/Magento/SalesRule/_files/coupon_cart_fixed_discount.php

@@ -41,7 +41,6 @@
 
             'store_id' => 0,
             'store_label' => 'TestRule_Coupon',
-
         ]
     ]
 );