PERF-10: fix add to cart for simple products with options

src/Model/Quote/Quote.php

@@ -11,6 +11,10 @@
  */
 namespace ScandiPWA\QuoteGraphQl\Model\Quote;
 
+use Magento\Catalog\Model\Product;
+use Magento\Catalog\Model\Product\Type\AbstractType;
+use Magento\Framework\DataObject;
+use Magento\Framework\Exception\LocalizedException;
 use Magento\Quote\Model\Quote as SourceQuote;
 
 /**
@@ -29,4 +33,36 @@ public function beforeSave()
         $this->setCustomerIsGuest($customerIsGuest);
         return $this;
     }
+
+    public function addProduct(
+        Product $product,
+                $request = null,
+                $processMode = AbstractType::PROCESS_MODE_FULL
+    )
+    {
+        if ($request === null) {
+            $request = 1;
+        }
+
+        if (is_numeric($request)) {
+            $request = $this->objectFactory->create(['qty' => $request]);
+        }
+
+        if (!$request instanceof DataObject) {
+            throw new LocalizedException(
+                __('We found an invalid request for adding product to quote.')
+            );
+        }
+
+        if (!$product->isSalable()) {
+            throw new LocalizedException(
+                __('Product that you are trying to add is not available.')
+            );
+        }
+
+        $productId = $product->getId();
+        $product = clone $this->productRepository->getById($productId, false, $this->getStore()->getId());
+
+        parent::addProduct($product, $request, $processMode);
+    }
 }