From 1cdca1b57f3810fd5b88d548b3ba12a86e5b95b8 Mon Sep 17 00:00:00 2001
From: Artjoms Travkovs <artjoms.travkovs@scandiweb.com>
Date: Thu, 31 Oct 2019 21:29:54 +0200
Subject: [PATCH 1/3] Added stock quantity check

---
 src/Model/Resolver/SaveCartItem.php | 39 +++++++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/src/Model/Resolver/SaveCartItem.php b/src/Model/Resolver/SaveCartItem.php
index d6ae014..86bfbea 100644
--- a/src/Model/Resolver/SaveCartItem.php
+++ b/src/Model/Resolver/SaveCartItem.php
@@ -36,6 +36,8 @@
 use Magento\Bundle\Model\Product\Type;
 use Magento\Framework\DataObject;
 use Magento\Catalog\Model\Product\Attribute\Repository;
+use Magento\CatalogInventory\Api\StockStatusRepositoryInterface;
+use Magento\Quote\Api\Data\CartItemInterface;
 
 /**
  * Class SaveCartItem
@@ -73,6 +75,16 @@ class SaveCartItem implements ResolverInterface
      */
     protected $quoteIdMaskResource;
     
+    /**
+     * @var Configurable
+     */
+    protected $configurableType;
+
+    /**
+     * @var StockStatusRepositoryInterface
+     */
+    protected $stockStatusRepository;
+
     /**
      * SaveCartItem constructor.
      * @param QuoteIdMaskFactory      $quoteIdMaskFactory
@@ -88,7 +100,9 @@ public function __construct(
         ParamOverriderCartId $overriderCartId,
         ProductRepository $productRepository,
         Repository $attributeRepository,
-        QuoteIdMask $quoteIdMaskResource
+        QuoteIdMask $quoteIdMaskResource,
+        Configurable $configurableType,
+        StockStatusRepositoryInterface $stockStatusRepository
     )
     {
         $this->quoteIdMaskFactory = $quoteIdMaskFactory;
@@ -97,6 +111,8 @@ public function __construct(
         $this->productRepository = $productRepository;
         $this->attributeRepository = $attributeRepository;
         $this->quoteIdMaskResource = $quoteIdMaskResource;
+        $this->configurableType = $configurableType;
+        $this->stockStatusRepository = $stockStatusRepository;
     }
     
     /**
@@ -228,6 +244,8 @@ public function resolve(
         $itemId = $this->getItemId($requestCartItem);
         if ($itemId) {
             $cartItem = $quote->getItemById($itemId);
+            $this->checkItemQty($cartItem, $qty);
+
             $cartItem->setQty($qty);
             $this->quoteRepository->save($quote);
         } else {
@@ -253,7 +271,24 @@ public function resolve(
         
         return [];
     }
-    
+
+    protected function checkItemQty(CartItemInterface $cartItem, $qty): void
+    {
+        $product = $cartItem->getProduct();
+
+        if ($cartItem->getProductType() === Configurable::TYPE_CODE) {
+            $attributesInfo = $cartItem->getBuyRequest()->getDataByKey('super_attribute');
+            $product = $this->configurableType->getProductByAttributes($attributesInfo, $product);
+        }
+
+        $stockStatus = $this->stockStatusRepository->get($product->getId());
+        $stockItem = $stockStatus->getStockItem();
+
+        if ($qty < $stockItem->getMinSaleQty() || $qty > $stockItem->getMaxSaleQty()) {
+            throw new GraphQlInputException(new Phrase('Provided quantity exceeds stock limits'));
+        }
+    }
+
     /**
      * @param string $sku
      * @param int    $qty

From 327fb54d7f31e91cda71313bdfef3b86a69bb03b Mon Sep 17 00:00:00 2001
From: Artjoms Travkovs <artjoms.travkovs@scandiweb.com>
Date: Thu, 14 Nov 2019 21:50:04 +0200
Subject: [PATCH 2/3] Added check for max stock qty

---
 src/Model/Resolver/SaveCartItem.php | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/Model/Resolver/SaveCartItem.php b/src/Model/Resolver/SaveCartItem.php
index 86bfbea..28b28d9 100644
--- a/src/Model/Resolver/SaveCartItem.php
+++ b/src/Model/Resolver/SaveCartItem.php
@@ -284,7 +284,10 @@ protected function checkItemQty(CartItemInterface $cartItem, $qty): void
         $stockStatus = $this->stockStatusRepository->get($product->getId());
         $stockItem = $stockStatus->getStockItem();
 
-        if ($qty < $stockItem->getMinSaleQty() || $qty > $stockItem->getMaxSaleQty()) {
+        $fitsInStock = $qty <= $stockItem->getQty();
+        $isInMinMaxSaleRange = $qty >= $stockItem->getMinSaleQty() || $qty <= $stockItem->getMaxSaleQty();
+
+        if (!($fitsInStock && $isInMinMaxSaleRange)) {
             throw new GraphQlInputException(new Phrase('Provided quantity exceeds stock limits'));
         }
     }

From afc54f8c4d346a25e2d1500d0c9ed09d2da203ea Mon Sep 17 00:00:00 2001
From: Artjoms Travkovs <artjoms.travkovs@scandiweb.com>
Date: Fri, 15 Nov 2019 20:40:19 +0200
Subject: [PATCH 3/3] Enhanced qty excceeded error handling

---
 src/Model/Resolver/SaveCartItem.php | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/Model/Resolver/SaveCartItem.php b/src/Model/Resolver/SaveCartItem.php
index 28b28d9..21d7563 100644
--- a/src/Model/Resolver/SaveCartItem.php
+++ b/src/Model/Resolver/SaveCartItem.php
@@ -256,13 +256,18 @@ public function resolve(
             }
             $newQuoteItem = $this->buildQuoteItem($sku, $qty, (int)$quoteId,
                 $requestCartItem['product_option'] ?? []);
-            
-            $quote->addProduct($product, $this->prepareAddItem(
-                $product,
-                $newQuoteItem
-            ));
-            $this->quoteRepository->save($quote);
-            
+
+            try {
+                $quote->addProduct($product, $this->prepareAddItem(
+                    $product,
+                    $newQuoteItem
+                ));
+
+                $this->quoteRepository->save($quote);
+            } catch (\Exception $e) {
+                throw new GraphQlInputException(new Phrase($e->getMessage()));
+            }
+
             // Related to bug: https://github.com/magento/magento2/issues/2991
             $quote = $this->quoteRepository->getActive($quoteId);
             $quote->setTotalsCollectedFlag(false)->collectTotals();