ENGCOM-3271: fixed Quote Item Prices are NULL in cart related events. #…

…18685 #18808

 - Merge Pull Request #18808 from ashutoshwebkul/magento2:2.2-develop
 - Merged commits:
   1. 09586e4
   2. 1638891
   3. 175ebc0
   4. 59bd874

app/code/Magento/Quote/Model/Quote/Item/Processor.php

@@ -97,6 +97,7 @@ public function prepare(Item $item, DataObject $request, Product $candidate)
         $item->addQty($candidate->getCartQty());
 
         $customPrice = $request->getCustomPrice();
+        $item->setPrice($candidate->getFinalPrice());
         if (!empty($customPrice)) {
             $item->setCustomPrice($customPrice);
             $item->setOriginalCustomPrice($customPrice);

app/code/Magento/Quote/Test/Unit/Model/Quote/Item/ProcessorTest.php

@@ -76,7 +76,8 @@ protected function setUp()
                 'addQty',
                 'setCustomPrice',
                 'setOriginalCustomPrice',
-                'setData'
+                'setData',
+                'setprice'
             ]);
         $this->quoteItemFactoryMock->expects($this->any())
             ->method('create')
@@ -98,7 +99,13 @@ protected function setUp()
 
         $this->productMock = $this->createPartialMock(
             \Magento\Catalog\Model\Product::class,
-            ['getCustomOptions', '__wakeup', 'getParentProductId', 'getCartQty', 'getStickWithinParent']
+            [
+                'getCustomOptions',
+                '__wakeup',
+                'getParentProductId',
+                'getCartQty',
+                'getStickWithinParent',
+                'getFinalPrice']
         );
         $this->objectMock = $this->createPartialMock(
             \Magento\Framework\DataObject::class,
@@ -239,13 +246,17 @@ public function testPrepare()
         $customPrice = 400000000;
         $itemId = 1;
         $requestItemId = 1;
+        $finalPrice = 1000000000;
 
         $this->productMock->expects($this->any())
             ->method('getCartQty')
             ->will($this->returnValue($qty));
         $this->productMock->expects($this->any())
             ->method('getStickWithinParent')
             ->will($this->returnValue(false));
+        $this->productMock->expects($this->once())
+            ->method('getFinalPrice')
+            ->will($this->returnValue($finalPrice));
 
         $this->itemMock->expects($this->once())
             ->method('addQty')
@@ -255,6 +266,9 @@ public function testPrepare()
             ->will($this->returnValue($itemId));
         $this->itemMock->expects($this->never())
             ->method('setData');
+        $this->itemMock->expects($this->once())
+            ->method('setPrice')
+            ->will($this->returnValue($this->itemMock));
 
         $this->objectMock->expects($this->any())
             ->method('getCustomPrice')
@@ -282,13 +296,17 @@ public function testPrepareWithResetCountAndStick()
         $customPrice = 400000000;
         $itemId = 1;
         $requestItemId = 1;
+        $finalPrice = 1000000000;
 
         $this->productMock->expects($this->any())
             ->method('getCartQty')
             ->will($this->returnValue($qty));
         $this->productMock->expects($this->any())
             ->method('getStickWithinParent')
             ->will($this->returnValue(true));
+        $this->productMock->expects($this->once())
+            ->method('getFinalPrice')
+            ->will($this->returnValue($finalPrice));
 
         $this->itemMock->expects($this->once())
             ->method('addQty')
@@ -298,6 +316,9 @@ public function testPrepareWithResetCountAndStick()
             ->will($this->returnValue($itemId));
         $this->itemMock->expects($this->never())
             ->method('setData');
+        $this->itemMock->expects($this->once())
+            ->method('setPrice')
+            ->will($this->returnValue($this->itemMock));
 
         $this->objectMock->expects($this->any())
             ->method('getCustomPrice')
@@ -325,13 +346,17 @@ public function testPrepareWithResetCountAndNotStickAndOtherItemId()
         $customPrice = 400000000;
         $itemId = 1;
         $requestItemId = 2;
+        $finalPrice = 1000000000;
 
         $this->productMock->expects($this->any())
             ->method('getCartQty')
             ->will($this->returnValue($qty));
         $this->productMock->expects($this->any())
             ->method('getStickWithinParent')
             ->will($this->returnValue(false));
+        $this->productMock->expects($this->once())
+            ->method('getFinalPrice')
+            ->will($this->returnValue($finalPrice));
 
         $this->itemMock->expects($this->once())
             ->method('addQty')
@@ -341,6 +366,9 @@ public function testPrepareWithResetCountAndNotStickAndOtherItemId()
             ->will($this->returnValue($itemId));
         $this->itemMock->expects($this->never())
             ->method('setData');
+        $this->itemMock->expects($this->once())
+            ->method('setPrice')
+            ->will($this->returnValue($this->itemMock));
 
         $this->objectMock->expects($this->any())
             ->method('getCustomPrice')
@@ -368,6 +396,7 @@ public function testPrepareWithResetCountAndNotStickAndSameItemId()
         $customPrice = 400000000;
         $itemId = 1;
         $requestItemId = 1;
+        $finalPrice = 1000000000;
 
         $this->objectMock->expects($this->any())
             ->method('getResetCount')
@@ -386,10 +415,16 @@ public function testPrepareWithResetCountAndNotStickAndSameItemId()
         $this->productMock->expects($this->any())
             ->method('getStickWithinParent')
             ->will($this->returnValue(false));
+        $this->productMock->expects($this->once())
+            ->method('getFinalPrice')
+            ->will($this->returnValue($finalPrice));
 
         $this->itemMock->expects($this->once())
             ->method('addQty')
             ->with($qty);
+        $this->itemMock->expects($this->once())
+            ->method('setPrice')
+            ->will($this->returnValue($this->itemMock));
 
         $this->objectMock->expects($this->any())
             ->method('getCustomPrice')